5.13. Renewable Polyvinyl Chloride
Most PVC resins are thermoplastic but some grades are cross-linkable.
5.13.1. Natural-Sourced Polyvinyl Chloride
Renewable PVC resin could be produced according to the ethylene–ethanol route. Solvay is developing bio-PVC. A project in Brazil is based on dehydration followed by chlorination of bioethanol. The objective is to reach 1/3 of the total PVC output.
Be careful: Soft bio-PVC compounds can be obtained thanks to fossil PVC and high bioplasticizer level (see next chapter).
5.13.2. Reminder of Fossil-Sourced Polyvinyl Chloride Resin General Properties
Partially renewable PVC are claimed having properties and characteristics of the same order as fossil PVC and could be processed by clients’ equipment without the need for any drastic adjustments. The following information deals with general properties of fossil PVC and, of course, some properties of renewable PVC can be different. So, keeping equal all the other parameters, do not make a short-sighted replacement of fossil polymer by the same weight of biosourced material without preliminary feasibility studies. Often, the recipe or/and processing conditions must be adjusted.
Table 5.64
Polypropylenes: Examples of Properties
| Reinforced PP | Homopolymer | Copolymer | Impact Modified | 10–40% Talc | 10–40% Mineral | 10–20% Glass Fiber | 30–40% Glass Fiber | |||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | |
| Miscellaneous properties | ||||||||||||||
| Density (g/cm3) | 0.90 | 0.91 | 0.90 | 0.91 | 0.88 | 0.91 | 0.97 | 1.25 | 0.97 | 1.25 | 0.97 | 1.05 | 1.10 | 1.23 |
| Shrinkage (%) | 1.0 | 3.0 | 2.0 | 3.0 | 2.0 | 3.0 | 0.9 | 1.4 | 0.6 | 1.4 | 0.3 | 1.0 | 0.1 | 1.0 |
| Absorption of water (%) | 0.01 | 0.10 | 0.01 | 0.10 | 0.01 | 0.10 | 0.01 | 0.03 | 0.01 | 0.03 | 0.01 | 0.02 | 0.01 | 0.02 |
| Mechanical properties | ||||||||||||||
| Shore hardness, D | 70 | 83 | 70 | 80 | 45 | 55 | 75 | 85 | 70 | 80 | 80 | 85 | 85 | 88 |
| Stress at yield (MPa) | 35 | 40 | 20 | 35 | 11 | 28 | 22 | 28 | 19 | 27 | 35 | 56 | 42 | 70 |
| Tensile strength (MPa) | 20 | 40 | 30 | 35 | 23 | 35 | 21 | 28 | 18 | 24 | 35 | 56 | 42 | 70 |
| Elongation at break (%) | 150 | 600 | 200 | 500 | 200 | 700 | 20 | 30 | 30 | 50 | 3 | 4 | 2 | 3 |
| Tensile modulus (GPa) | 1.1 | 1.6 | 1.0 | 1.2 | 0.4 | 1.0 | 1.5 | 3.5 | 1 | 3.5 | 2.8 | 4 | 4 | 10 |
| Flexural modulus (GPa) | 1.2 | 1.6 | 1.0 | 1.4 | 0.4 | 1.0 | 1.5 | 4 | 1.4 | 3.1 | 2.5 | 3.5 | 4 | 7 |
| Notched impact strength ASTM D256 (J/m) | 20 | 60 | 60 | 500 | 110 | NB | 30 | 200 | 38 | 110 | 50 | 145 | 45 | 160 |
| Thermal properties | ||||||||||||||
| Heat distortion temperature (HDT) B (0.46 MPa) (°C) | 100 | 120 | 85 | 104 | 75 | 88 | 100 | 127 | 85 | 113 | 110 | 140 | 140 | 155 |
| HDT A (1.8 MPa) (°C) | 50 | 60 | 50 | 60 | 46 | 57 | 56 | 75 | 50 | 68 | 90 | 127 | 125 | 140 |
| Table Continued | ||||||||||||||
| Reinforced PP | Homopolymer | Copolymer | Impact Modified | 10–40% Talc | 10–40% Mineral | 10–20% Glass Fiber | 30–40% Glass Fiber | |||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | |
| Vicat softening point A (°C) | 154 | 154 | 135 | 152 | 135 | 152 | 137 | 153 | 150 | 162 | ||||
| Vicat softening point B (°C) | 90 | 92 | 45 | 73 | 45 | 73 | 46 | 100 | 96 | 128 | ||||
| Continuous use temperature (°C) | 120 | 130 | 110 | 130 | 100 | 115 | 110 | 130 | 110 | 130 | 110 | 130 | 110 | 130 |
| Glass transition temperature (°C) | −10 | −10 | −20 | −20 | −20 | −20 | −20 | −10 | −20 | −10 | −20 | −10 | −20 | −10 |
| Melting temperature (°C) | 168 | 173 | 155 | 173 | 150 | 168 | 160 | 173 | 160 | 173 | 160 | 173 | 160 | 173 |
| Minimum service temperature (°C) | −20 | −10 | −20 | −10 | −40 | −20 | −20 | −5 | −20 | −5 | −40 | −5 | −30 | −5 |
| Thermal conductivity (W/m K) | 0.15 | 0.21 | 0.15 | 0.21 | 0.15 | 0.21 | 0.3 | 0.4 | 0.3 | 0.4 | 0.2 | 0.3 | 0.3 | 0.3 |
| Specific heat (cal/g/°C) | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 | ||||||||
| Coefficient of thermal expansion (10−5/°C) | 6 | 17 | 7 | 17 | 7 | 17 | 4 | 8 | 3 | 6 | 4 | 7 | 2 | 3 |
| Electrical properties | ||||||||||||||
| Volume resistivity (ohm cm) | 1016 | 1018 | 1016 | 1018 | 1016 | 1018 | 1016 | 1017 | 1016 | 1017 | 1016 | 1017 | 1016 | 1017 |
| Dielectric constant | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.3 | 2.6 | 2.6 | 2.6 | 2.6 |
| Loss factor (10−4) | 3 | 5 | 3 | 5 | 3 | 5 | 7 | 11 | 7 | 11 | 10 | 20 | 10 | 20 |
| Dielectric strength (kV/mm) | 20 | 28 | 20 | 28 | 20 | 28 | 30 | 70 | 30 | 70 | 30 | 45 | 30 | 45 |
| Arc resistance (s) | 135 | 180 | 135 | 180 | 135 | 180 | 100 | 130 | 100 | 130 | 75 | 100 | 60 | 75 |
| Table Continued | ||||||||||||||
| Reinforced PP | Homopolymer | Copolymer | Impact Modified | 10–40% Talc | 10–40% Mineral | 10–20% Glass Fiber | 30–40% Glass Fiber | |||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | |
| Fire behavior | ||||||||||||||
| Oxygen index (%) | 17 | 18 | 17 | 18 | 17 | 18 | 17 | 18 | 17 | 18 | 17 | 18 | 17 | 18 |
| UL94 fire rating | HB | HB | HB | HB | HB | HB | HB | HB | HB | HB | HB | HB | HB | HB |
| General chemical properties are subject to the compatibility of the fillers and reinforcements with the ambient conditions. If the fillers are well adapted, the chemical properties are the same for filled and neat polymers. | |
| Light | UV stabilizers or/and black color with suitable carbon blacks are needed |
| Weak acids | Good behavior |
| Strong acids | Good behavior except oxidizing acids |
| Weak bases | Good behavior |
| Strong bases | Good behavior |
| Solvents | Good behavior up to 60°C except chlorinated solvents, certain oxidants, aromatic hydrocarbons |
| Copper, manganese, and cobalt are oxidation catalysts and must be avoided, in particular, for inserts | |
| Food contact | Possible for special grades |
5.13.2.1. Overview of Fossil Polyvinyl Chloride
Several acronyms are used for different PVCs:
• S-PVC for suspension PVC
• E-PVC for emulsion PVC
• M-PVC for mass or bulk PVC
• PVC-U for unplasticized PVC
• PVC-P for plasticized PVC
• PVC-HI for high impact PVC.
Pure PVC is the linear homopolymer of vinyl chloride. The industrial polymers are amorphous with a backbone identical to those of polyethylene, PP, and polybutene but the pendant chlorine atoms result in a polar polymer. The theoretical chlorine content is roughly 57%.
PVC can be polymerized, possibly with a comonomer (mainly vinyl acetate):
• In an emulsion, the oldest process. The presence of emulsifiers at a greater or lesser level gives a variable haze to the finished articles, eases the processing, decreases the electrostatic buildup, and increases the absorption of water. E-PVC, dispersion PVC, or PVC pastes are used to make plastisols and organosols.
• In suspension. This process gives transparent parts, good electrical properties, and a weak absorption of water.
• In bulk. PVC is free from additives such as protective emulsifiers, dispersants, or colloids, which makes it possible to obtain parts that are even more transparent and glossy than suspension PVC.
• In solution. Today this technique is obsolete.
The property sets of raw PVCs as-polymerized are generally unsuitable for the range of intended applications. It is essential to upgrade and customize the raw polymers by compounding to satisfy the requirements of customers and applications. Numerous additives, fillers, plasticizers, stabilizers, etc., are used, allowing the manufacture of various parts and goods from a very rigid to a very soft character.
Albeit starting from a single and simple chemical formula, PVC leads to a myriad of products with very different properties. In general, and where no other indication is given, the following features relate to rigid PVC.
In addition to this diversity, a few PVC products, cables, or foams, for example, are cross-linked.
PVCs can be classified versus:
• Their molecular weight or degree of polymerization, often expressed as K value or K-wert, inferred from viscosity measurements. Fig. 5.48A and B displays some examples of polymerization degrees and molecular weights versus K values. Slightly different data can be found quoted elsewhere because several methods to measure K values exist.
• Rigidity or plasticization: rigid or unplasticized PVC (PVC-U), semirigid PVC, flexible or soft PVC.
• The type of processing: in the melt state, in the liquid state (plastisols or organosols), foams. Plastisols have very special mechanical, thermal, and chemical properties due to their high flexibility and the use of large amounts of plasticizers.
The particular morphology of foams induces the following:
• A decrease in the mechanical properties due to the low quantity of polymer and the high proportion of gas.
• A weaker chemical resistance due to the highly divided state of the polymer. The thin cell walls immediately absorb liquids and gases.
Lastly, PVC/PVAC are the most-used copolymers for some specialty application niches. They are appreciated for their lower melt viscosities, higher tolerance to additive fillers, and better cold-draw properties than homopolymers.
Figure 5.48 (A) PVC (polyvinyl chloride): examples of polymerization degrees versus K values. (B) PVC: examples of molecular weights versus K values.
Advantages
PVC is regarded as perhaps the most versatile thermoplastic resin, due to its ability to accept an extremely wide variety of additives: Plasticizers, stabilizers, fillers, processing aids, impact modifiers, lubricants, foaming agents, biocides, pigments, reinforcements…
General advantages depend on the type of compound.
Rigid PVC is appreciated for its rigidity at room temperature, low price, chemical resistance except to certain solvents, dimensional stability, easy welding and joining, resistance to weathering for well-optimized compounds, possibility of transparency, food contact, fireproofing.
Flexible PVC is appreciated for the versatility of its characteristics according to the formulation. Significant quantities of fillers and plasticizers are used to optimize some of the characteristics such as behavior at low temperatures, fire resistance, flexibility and hardness in the elastomer range, low price, electric insulation, easy welding and joining, possibility of transparency, food contact, fireproofing.
Plastisols allowing the use of particular liquid-state processing techniques: casting, rotomolding, dipping, coating…
Drawbacks
PVC by itself cannot be processed, it must be compounded with at least a stabilizer, a lubricant, and, if flexible, a plasticizer.
PVCs are currently handicapped by the ecological problems associated with chlorine and also with some of the plasticizers for the flexible products.
Rigid PVC is inherent sensitivity to UV without protection (but adequate compounds exist); softening and creep when the temperature rises; attack by aromatic or chlorinated hydrocarbons as well as by esters and ketones; impact sensitivity, the more so as the temperature decreases; high density; fume toxicity and corrosivity in the event of fire; less easy to inject; tool corrosion.
Flexible PVC suffers from the same drawbacks as rigid PVC the more so as the amount of plasticizer increases, increasing creep, fire sensitivity (except for FR plasticizers), fume toxicity and corrosivity, and decreasing chemical resistance and thermal aging resistance.
Special Grades
These can be classified according to the type of processing, specific properties, targeted applications:
• extrusion, injection, compression, blown film, thermoforming, calendering, blow molding, rotational molding, foam, slush molding, coating, powdering, coextrusion, for thin or thick parts, for plastisols…
• stabilized against heat, UV, light and weathering; antistatic, conductive, reinforced, food contact, approved for medical applications, fireproofed, transparent, low warpage, high fluidity, low to high K-values, high plasticizer absorption, low fogging, very low fisheye level…
• for films, sheets, tubes, wire and cable coatings, fibers, mass-produced goods…
Recycled PVC is proposed with cost and environmental advantages.
Processing
All the molten-state processing methods are usable: extrusion, injection, compression, blown film, blow molding, rotational molding, thermoforming, foam, coating, powdering, coextrusion, fluidized bed, machining for high hardness grades, welding. Special grades can be cross-linked after shaping.
Processing methods in the liquid state are also used: casting, rotomolding, dipping, coating…
Applications
Although varying according to the country, consumption is approximately divided into the following:
• 68% rigid PVC
• 31% flexible PVC
• 1% in other applications.
The main application sector by far is the building and construction sector, which consumes more than two-thirds of all PVC. Then there are multiple applications in packaging, electrical and electronics (EE), home and leisure, medical, automotive, industry…
• Building and construction
• pipes and fittings consume 47% of the PVC total for potable water, sewer, irrigation, drain, rainwater, soil and waste systems, venting, ducting, fire sprinkler piping, chemical and food processing… Physical forms are very diverse, from monolayer tubes to corrugated or multilayer pipes, spiral wound, small or large diameter…
• siding consumes 15% of all PVC with gutters, downspouts, boardings…
• windows and doors consume 4% of the PVC total with shutters, architectural glazing systems, conservatory devices…
• fencing, barriers, decking…
• docking, landfill liners, membranes, swimming pool liners…
• internal and external cladding, roofing and ceiling systems…
• flooring and wall covering…
• Packaging
• films and sheets for packaging and thermoforming consume 7% of the total for PVC
• clear and opaque bottles consume 1% of all PVC
• food and nonfood packaging, various containers for chemicals, clear blisters…
• jar lid gasketing…
• Electricity, electronics and appliances
• wire and cable insulation consumes 4% of the PVC total with construction and automobile wires, electrical cord jacketing, fiber optic sheathing, heat-shrinkable sleeves…
• components in phone systems, power tools, refrigerators, washing machines, air conditioners, computers, keyboards, housings…
• floppy disk jackets…
• Home and leisure sector applications consume 7% of the total for PVC
• garden hoses
• toys, dolls, fishing lures, fancy goods…
• inflatable covers, structures and devices…
• shoe soles
• coated fabrics for clothing, leather working, opaque curtains, tarpaulins…
• films and sheets for adhesive tapes, translucent curtains, school and office stationery…
• upholstery, covering, padding…
• patio furniture
• coated metal racks and shelving…
• credit cards
• strapping, fibers…
• Medical applications consume 4% of all PVC
• fluid bags and containers for blood, plasmas, intravenous solutions, urine continence…
• blood vessels for artificial kidneys, heart and lung bypass sets…
• tubing, catheters, cannulas, endotracheal tubing, feeding and pressure monitoring tubing…
• artificial skin in emergency burns treatment
• drip chamber components
• inflatable splints, prosthetics…
• surgical and examination gloves, inhalation masks, overshoes, protective sheeting and tailored covers, mattress and bedding covers, antibump protection bars…
• blisters and dosage packs for pharmaceuticals and medicines, single dose medication packaging, shatter-proof bottles and jars…
• The automotive and transportation sector consumes 2% of the PVC total
• instrument panels and associated moldings, dashboards, interior door panels and pockets, sun visors, security covers, headlining, floor coverings, floor mats, arm rests, seat coverings…
• exterior side moldings, protective strips, window trims, body side moldings…
• underbody antiabrasion coating, mud flaps, antistone damage protection…
• body seam sealing, seals, foamed gaskets…
A new and fast-developing application is “synthetic wood” or “wood plastic composite” (i.e., WPC) made from rigid PVC heavily filled with wood flour and other natural fibers, extruded in wood-like profiles that can be sawn, nailed, and screwed just like natural wood (see Chapters 6 and 8 for more details).
Thermal Behavior
The continuous use temperatures in an unstressed state are generally estimated up to 90°C for a rigid PVC and 80°C or less for a flexible PVC.
Service temperatures are definitely lower under mechanical stress because of modulus decay, strain, creep, relaxation… They can be of the order of 50°C up to 80°C according to the HDT and applied stresses.
For example,
• for a flexible PVC, the stress at 60°C is half that at 20°C
• for a given rigid PVC, the tensile strength falls by 50% between 20°C and 60°C and the HDT A (1.8 MPa) is 65°C.
For a given grade of PVC (30% plasticizer), the retention of short-term tensile strength and elongation at break versus temperature is shown in Fig. 5.49. The short-term retention of tensile strength falls to roughly 30% at 80°C and, at the same time, the elongation at break retention roughly doubles.
Figure 5.49 PVC (polyvinyl chloride): examples of retentions of tensile strengths (TS, %) and elongations at break (EB, %) versus temperature (°C).
For long-term heat aging, PVC follows two degradation pathways:
• an oxidative reaction like numerous other polymers, which can be compensated for with antioxidants
• dehydrochlorination, releasing hydrochloric acid (HCl), which needs compounding with very effective protective stabilizers to prevent this.
The UL temperature indices of specific grades can be as follows:
• 50–90°C for the electrical properties alone
• 50–85°C for electrical and mechanical properties, excluding impact strength
• 50–70°C for electrical and mechanical properties, including impact strength.
Rigid PVCs are brittle materials with a minimum service temperature of the order of 0°C to −10°C.
Plasticized PVCs are more resistant and, according to the type and amount of plasticizers, can have a minimum service temperature of the order of −5°C down to −50°C.
The glass transition temperature (Tg) range for rigid PVC by DSC measurements is roughly 60–100°C. After plasticization, the Tg range can be from −5°C down to −50°C.
These results relate to some grades only and cannot be generalized.
5.13.2.2. Optical Properties
PVC can be transparent to opaque according to the grade. The light transmission for the 500–800 nm region can be as high as 85–90% with a haze of 2.5% and a refractive index of about 1.53–1.54.
These results relate to some grades only and cannot be generalized.
5.13.2.3. Mechanical Properties
Rigid PVC is a stiff and brittle material with rather high modulus and tensile strength but low elongation at break and weak impact strength.
After plasticization, the behavior can be totally different, with very low moduli and tensile strength, high elongation at break, and better impact resistance.
The coefficients of friction are rather high, 0.4–0.45, for example, or higher for some plasticized grades.
Dimensional Stability
Rigid PVC is an amorphous polymer with low shrinkage, a fair coefficient of thermal expansion for a polymer, limited creep at room temperature, and low water absorption by moisture exposure.
This good dimensional stability can be altered by plasticization to a greater or lesser degree.
Poisson’s Ratio
Poisson’s ratio depends on numerous parameters concerning the grade used and its processing, the temperature, the possible reinforcements, the direction of testing with regard to the molecular or reinforcement orientation. For a given sample, it was evaluated at 0.35 for a rigid PVC and significantly higher for a flexible grade. This is an example only that cannot be generalized.
Creep
Rigid PVCs have average moduli, which limits strains and leads to average creep moduli at room temperature. After plasticization, the very low moduli involve high strains for moderate stresses and low creep moduli even at room temperature.
When the temperature rises, creep increases and creep moduli fall.
Fig. 5.50A displays examples of creep under relatively high stresses (10–30 MPa) for rigid PVC at room temperature. We can note that the creep moduli are much higher than those of polyethylene or PP (less than 1 GPa).
Fig. 5.50B displays examples of creep under relatively high stresses (7–14 MPa) at room temperature for impact-modified rigid PVC or PVC-HI. Times are much longer than for the previous graph (20,000 h versus 400). Compared to Fig. 5.50A, the plasticization decreases the creep moduli. However, they are always higher than those of polyethylene or PP (less than 1 GPa) for a same creep time.
Relaxation
Fig. 5.51A and B displays the same relaxation data expressed as stress retention, the first with an algebraic time scale showing the fast drop of stress at the start of test and the second with a logarithmic time scale showing a regular decrease of stress.
Figure 5.50 (A) Rigid PVC (polyvinyl chloride): examples of creep modulus (GPa) versus time (h) for various stresses (MPa). (B) PVC-HI: examples of creep modulus (GPa) versus time (h) for various stresses (°C).
Figure 5.51 (A) Stress relaxation of PVC (polyvinyl chloride): examples of stress retention (%) versus time (h) under 0.5% strain at 20°C. (B) Stress relaxation of PVC: examples of stress retention (%) versus time (h) under 0.5% strain at 20°C.
These results relate to one grade only and cannot be generalized.
5.13.2.4. Aging
Dynamic Fatigue
The dynamic fatigue can be fair for certain grades if care is taken to limit the strains by restricting the stresses to values in keeping with the low elongation at break of the rigid PVCs.
For a given grade of PVC, Fig. 5.52 displays an example of the SN or Wöhler’s curve concerning flexural tests with maximum stress of ±σ and average stress of 0.
Weathering
PVC resists hydrolysis well but is naturally sensitive to light and UV. It must be protected by addition of anti-UV and other protective agents. In these cases, long warranty periods can be allowed, for example, 10 years and more. For a white, protected, rigid PVC, after natural weathering for 3 years in Michigan, the retention of impact strength is 68% and the yellowness index increases by 5.
Figure 5.52 SN curve of rigid PVC (polyvinyl chloride): examples of maximum stress (MPa) versus number of cycles at rupture (N).
These results are examples only and they cannot be generalized.
High-Energy Radiation
PVC behaves well when exposed to high-energy radiation (electron beam, gamma rays) in the absence of oxygen.
In the presence of air, it yellows and releases chlorine even for weak doses of irradiation. It is preferable to avoid sterilization by high-energy radiation.
However, it is possible to cross-link exceptional compounds by high-energy radiation under particular conditions. This method is used, for example, for cable coating and foams.
These results are examples only and they cannot be generalized.
Behavior at High Frequencies
PVCs have high loss factors, about 100 × 10−4, and heat up under high-frequency current. They can be welded by this technique.
Chemicals
Rigid PVC absorbs little water and is not very sensitive to it.
Appropriate grades are approved for food contact or for medical applications.
Chemical inertia is generally fair up to 60°C.
PVC resists dilute acids, dilute alkalis, and aliphatic hydrocarbons well.
PVC is attacked by aromatic hydrocarbons, chlorinated solvents, esters, ethers, and ketones.
Resistance to oils, greases, and alcohols is variable.
The chemical resistance of flexible PVC can be strongly reduced and the absorption of water can be appreciably higher.
Table 5.65 displays general assessments of behavior for given grades after prolonged immersion in a range of chemicals at room temperature. The results are not necessarily representative of all the fossil PVC and bio-PVC. These general indications should be verified by consultation with the producer of the selected grades and by tests under operating conditions.
Permeability
For films, in several series of experiments concerning various thicknesses of various polymers, permeability coefficients have been calculated for a reference thickness of 40 μm. Units differ for the various gases but are comparable for the different polymers tested with the same gas. The following data (without units) are only given to provide some idea and cannot be used for designing any parts or goods.
• Water vapor: rigid and flexible PVCs have permeabilities evaluated at 8 and 20, respectively, compared to a full range of 0.05 up to 400 for all tested plastics.
• Gases: rigid and flexible PVCs have permeabilities, evaluated at
• air: 28 and 550 versus a full range of 3 up to 2750 for all tested plastics
• carbon dioxide: 200 and 8500 versus a full range of 30 up to 59,000 for all tested plastics
• nitrogen: 12 and 350 versus a full range of 1 up to 3500 for all tested plastics
• oxygen: 87 and 1500 versus a full range of <1 up to 11,000 for all tested plastics.
Fire Resistance
Due to the chlorine content, the fire resistance is inherently better than for hydrocarbon polymers. Rigid PVC is self-extinguishing but releases chlorine during combustion. Oxygen indices are about 45 but can decrease with some plasticizers.
Table 5.65
PVC (Polyvinyl Chloride): Examples of Chemical Behavior at Room Temperature
| Chemicals | Concentration (%) | Estimated Behavior | |
| Rigid PVC (Polyvinyl Chloride) | Plasticized PVC | ||
| Acetic acid | 10–96 | l | l |
| Acetic aldehyde | 100 | n | n |
| Acetic anhydride | 100 | n | n |
| Acetone | 100 | n | n |
| Acetonitrile | 100 | n | n |
| Acetophenone | 100 | n | n |
| Aluminum chloride | Solution | S | S |
| Aluminum sulfate | Unknown | S | S |
| Ammonium hydroxide | 30 | S | S |
| Ammonium sulfate | 50 | S | S |
| Amyl acetate | 100 | n | n |
| Amyl alcohol | 100 | S | S |
| Aniline | 100 | n | n |
| Aqua regia | Unknown | l | n |
| Arsenic acid | Unknown | S | S |
| ASTM1 oil | 100 | S | S |
| ASTM2 oil | 100 | S | S |
| ASTM3 oil | 100 | S | S |
| Barium chloride | Saturated | S | S |
| Benzaldehyde | 100 | n | n |
| Benzene | 100 | n | n |
| Benzyl alcohol | 100 | S | S |
| Boric acid | Unknown | S | S |
| Bromine (liquid) | 100 | n | n |
| Butanol | 100 | S | S |
| Butyl acetate | 100 | n | n |
| Butyric acid | Unknown | S | S |
| Calcium chloride | Unknown | S | S |
| Carbon sulfide | 100 | n | n |
| Carbon tetrachloride | 100 | l | l |
| Castor oil | 100 | S | S |
| Chlorine (dry gas) | 100 | l | l |
| Table Continued | |||
| Chemicals | Concentration (%) | Estimated Behavior | |
| Rigid PVC (Polyvinyl Chloride) | Plasticized PVC | ||
| Chlorine water | Unknown | l | l |
| Chloroacetic acid | Unknown | S | n |
| Chlorobenzene | 100 | n | n |
| Chloroform | 100 | n | n |
| Chlorosulfonic acid | Unknown | l | n |
| Chromic acid | Unknown | S | S |
| Citric acid | 10 | S | S |
| Copper sulfate | Unknown | S | S |
| Cyclohexane | 100 | S | S |
| Dichloroethylene | 100 | n | n |
| Diethylamine | 100 | l | n |
| Diethylene glycol | 100 | S | S |
| Diethylether | 100 | n | n |
| Dimethylamine | 100 | l | l |
| Dimethylformamide | 100 | n | n |
| Dioctylphthalate | 100 | n | n |
| Ethanol | Unknown | S | S |
| Ethyl acetate | 100 | n | n |
| Ethyl chloride | 100 | n | n |
| Ethylene glycol | 100 | S | S |
| Fluosilicic acid | Unknown | S | S |
| Formic acid | 40–85 | S | S |
| Freon 11 | 100 | l | l |
| Furfural | 100 | n | n |
| Glycerol | 100 | S | S |
| Hexane | 100 | S | S |
| Hydrazine | 100 | S to l | n |
| Hydrobromic acid | 48 | S | S |
| Hydrochloric acid | 10–36 | S | S |
| Hydrofluoric acid | 40 | l | l |
| Hydrogen peroxide | 30 | S | S |
| Hydrogen peroxide | 90 | S to l | n |
| Table Continued | |||
| Chemicals | Concentration (%) | Estimated Behavior | |
| Rigid PVC (Polyvinyl Chloride) | Plasticized PVC | ||
| Hydrogen sulfide gas | Unknown | S | S |
| Iron(III) chloride | Unknown | S | S |
| Isopropanol | 100 | S | S |
| Lactic acid | 90 | l | l |
| Lead acetate | 10 | S | S |
| Linseed oil | 100 | S | S |
| Liquid paraffin | 100 | S | S |
| Magnesium chloride | Unknown | S | S |
| Mercury chloride | Unknown | S | S |
| Methanol | 100 | S | l |
| Methyl bromide | 100 | n | n |
| Methylene chloride | 100 | l | n |
| Methyl ethyl ketone | 100 | n | n |
| Mineral oil | 100 | S | S |
| Monoethanolamine | Unknown | n | n |
| Nickel chloride | Unknown | S | S |
| Nitric acid | 10 | S | S |
| Nitric acid | 65 | S | n |
| Nitric acid | >75 | n | n |
| Nitrobenzene | 100 | n | n |
| Oleic acid | Unknown | S | S |
| Olive oil | 100 | S | S |
| Oxalic acid | Unknown | S | S |
| Ozone | Unknown | S | S |
| Perchloroethylene | 100 | n | n |
| Petroleum | 100 | S to l | l |
| Phenol | Unknown | l | n |
| Phosphoric acid | 85 | S | S |
| Picric acid | Solution | S | S |
| Potassium cyanide | Unknown | S | S |
| Potassium fluoride | Unknown | S | S |
| Potassium hydroxide | 45 | S | S |
| Table Continued | |||
| Chemicals | Concentration (%) | Estimated Behavior | |
| Rigid PVC (Polyvinyl Chloride) | Plasticized PVC | ||
| Potassium permanganate | 20 | S | S |
| Potassium sulfate | Unknown | S | S |
| Propanol | 100 | S | S |
| Pyridine | Unknown | n | n |
| Seawater | 100 | S | S |
| Silver nitrate | Unknown | S | S |
| Sodium borate | Unknown | S | S |
| Sodium carbonate | 10 | S | S |
| Sodium chloride | 25 | S | S |
| Sodium cyanide | Unknown | S | S |
| Sodium hydroxide | 10–55 | S | S |
| Sodium hypochlorite | 20 | S | S |
| Sodium nitrate | Solution | S | S |
| Sulfamic acid | Solution | S | S |
| Sulfuric acid | 10–70 | S | S |
| Sulfuric acid | 96 | l to n | n |
| Sulfuric acid | Fuming | n | n |
| Sulfurous anhydride (gas) | Unknown | S | S |
| Thionyl chloride | 100 | n | n |
| Tin chloride | Unknown | S | S |
| Toluene | 100 | n | n |
| Transformer oil | 100 | S | S |
| Trichloroethane | 100 | n | n |
| Trichloroethylene | 100 | n | n |
| Tricresylphosphate | Unknown | n | n |
| Triethylamine | Unknown | S | l |
| Turpentine oil | 100 | S | S |
| Vegetable oil | 100 | S | S |
| Water | 100 | S | S |
| Xylene | 100 | n | n |
| Zinc chloride | Unknown | S | S |
Flexible PVC generally burns more easily than rigid PVC, the more so the higher the level of flammable plasticizers. Oxygen indices as low as 20 are quoted. Using fire-retardant plasticizers the oxygen index can reach 40.
5.13.2.5. Electrical Properties
PVCs are good insulators even in a wet environment, with fair dielectric resistivities and rigidities, and rather high loss factors. Resistivity decreases when the temperature rises. PVCs heat up under high-frequency current and microwaves.
Special grades and compounds are marketed for electrical applications such as the insulation of wires and cables.
The transverse resistivity of plasticized PVCs decreases as the plasticizer content increases.
5.13.2.6. Joining, Decoration
Welding is easy by all the processes for rigid PVCs. Sometimes it can be more difficult for flexible PVCs and even impossible by frictional techniques for very soft compounds.
Gluing is easy for rigid PVCs including using solutions of PVC. Sometimes it can be more difficult for flexible PVCs.
All precautions must be taken concerning health and safety according to local laws and regulations.
5.13.2.7. Foams
Unlike industrial solid polymers, which are processed as carefully as possible to avoid the formation of bubbles, vacuoles, etc., alveolar materials result from the desire to introduce, in a controlled way, a certain proportion of voids with the aim of
• increasing flexibility: very soft seals.
• improving the thermal or phonic insulating character: foams for building, automotive…
• making damping parts: foams for packaging, automotive, and transport safety parts.
The alveolar materials consist of a polymer skeleton surrounding the cells, which may be closed or partially or completely open to neighboring cells or the outside.
The intrinsic properties come from those of the PVC with the following:
• a reduction in the mechanical properties due to the small quantity of material and the high proportion of gas
• a reduction in the chemical behavior due to the highly divided nature of the material. The thin cell walls immediately absorb liquids and gases and are rapidly damaged.
Generally, the properties of the PVC foams are as follows:
• densities from 30 kg/m3 up to 700 kg/m3 for rigid foams and 50 kg/m3 up to 100 kg/m3 for flexible foams
• rigid to flexible
• closed or open cells
• cross-linked or linear: often, cross-linking improves the mechanical properties and chemical resistance.
The absorption and the permeability to water or moisture are low for those foams with closed cells and their hydrolysis behavior is generally fair.
The fire resistance is inherently good and can be improved by an appropriate formulation, but PVC contains a high chlorine level that is released in the event of combustion and can involve corrosion during processing. The thermal behavior is limited.
PVC foams (Table 5.66) have
• insulating properties
• damping properties
• fair mechanical characteristics according to their density
• a low absorption and permeability to water or moisture for closed cell foams and excellent hydrolysis behavior
• a naturally fair fire resistance that can be improved by an appropriate formulation
• ease of machining with tools used for wood. PVC foams can be glued, welded, stamped, and thermoformed.
Table 5.66 shows some examples of PVC foam properties. These data cannot be used for designing. A specific property is the ratio of the actual property value divided by the density.
Table 5.66
Examples of the Properties of PVC (Polyvinyl Chloride) Foams
| Cross-linked PVC Foams | ||||||
| Density (kg/m3) | 30 | 100 | 400 | |||
| Property | Property | Property | ||||
| Actual | Specific | Actual | Specific | Actual | Specific | |
| Density (g/cm3) | 0.03 | 0.1 | 0.4 | |||
| Maximum service temperature (°C) | 80 | 70–80 | ||||
| Minimal service temperature (°C) | −200 | −200 | −200 | |||
| Compression strength (MPa) | 0.220 | 7.3 | 1.700 | 17 | 11.240 | 28 |
| Compression modulus (GPa) | 0.012 | 0.4 | 0.125 | 1.25 | 0.500 | 1.2 |
| Tensile strength (MPa) | 0.510 | 17 | 3.100 | 31 | 12.400 | 31 |
| Tensile modulus (GPa) | 0.020 | 0.67 | 0.105 | 1.05 | 0.469 | 1.2 |
| Thermal conductivity (W/m K) | 0.029 | 0.023 | 0.059 | |||
| Water absorption, 7 days, 40°C (%) | 0.11 | 0.02 | ||||
| Poisson’s ratio | 0.32 | |||||
| Coefficient of thermal expansion (10−5/°C) | 4 | 3.5 | 2.2 | |||
| Linear PVC Foams | ||||||
| Density (kg/m3) | 60 | 90 | 140 | |||
| Density (g/cm3) | 0.06 | 0.09 | 0.14 | |||
| Compression strength (MPa) | 0.380 | 6.3 | 0.900 | 10 | 1.600 | 11.4 |
| Compression modulus (GPa) | 0.030 | 0.5 | 0.056 | 0.6 | 0.135 | 1 |
| Tensile strength (MPa) | 0.900 | 15 | 1.400 | 15.6 | 2.400 | 17 |
| Tensile modulus (GPa) | 0.030 | 0.5 | 0.050 | 0.56 | 0.090 | 0.6 |
| Thermal conductivity (W/m K) | 0.034 | 0.037 | 0.039 | |||
Examples of Applications
Composites
• Sandwich panels for body structures of refrigerated lorries and similar vehicles; roofs of coaches; structural components; containers for maritime, road, railway and air transport; wagons to carry and store food onboard aircraft; shelters, bodies of military light machines.
• Nautical structural components: hulls, decks, superstructures and partitions of motorboats; vessels for fishing or racing.
• Structural and interior components for aeronautic, automotive, and railway equipment: floors, radomes, bodies of buses and coaches (Neoplan), front-end components, drivers’ cabs, partition walls, luggage racks in high-speed trains.
Building and civil engineering
• Thermal insulation of roofs, walls, ceilings, floors.
• Thermal insulation of sandwich panels for industrial construction.
Nautical
• Life jackets, life suits.
• Safety padding.
• Buoys.
• Floats for cables and other devices…
Sports and leisure
• Gym mats, padding, damping, and insulating mats.
• Protective devices for various sports such as hockey, basket, soccer, boxing…
• Padding of helmets and seats for babies and children…
Industry
• Machine soundproofing.
• Impact and vibration damping.
Miscellaneous
• Panels for showrooms, display units…
• Scenery…
• Shop fittings…
• Insulation of tanks, pipes…
• Packaging of fragile goods, warm or cold foods…
• Scale models, do-it-yourself…
5.13.2.8. Trade Name and Producer Examples
Trade names examples: Astralon, Exon, Fiberloc, Geon, Hostalit, Igelite, Lucoflex, Lucovyl, Marvinol, Norvinyl, Opalon, Ortodur, Pevikon, Polychlorovinyl, Polytherm, Porodur, Trovidor, Viniplast, Viniplaen, Vinnol, Vinoflex, Yugovinyl.
Foams: Airex, Celuform, Divinycell, Forex, Herex, Klegecell, Vestolit TSE…
Producer examples
| Arkema | http://www.arkema.com/ |
| Asahi Glass Corp | http://www.agc.com/ |
| China-Bluestar | http://www.china-bluestar.com/ |
| Formosa Plastics | http://www.fpcusa.com/ |
| Georgia Gulf | http://www.ggc.com/ |
| Ineos | http://www.ineos.com/ |
| LG Chemical | http://lgchemical.en.chemnet.com/ |
| Mexichem | http://www.mexichem.com/ |
| Oxychem | http://www.oxy.com/ |
| Petkim | http://www.petkim.com.tr/ |
| Qingdao Haijing Chemical Group | http://www.haijing.com/english/ |
| RusVinyl | http://www.rusvinyl.ru/ |
| Shin Etsu | http://www.shinetsu.co.jp/ |
| Solvay | http://www.solvay.com/ |
| Taiyo Vinyl Corp. | http://www.taiyo-vinyl.co.jp/ |
| Vinnolit | http://www.vinnolit.de/ |
| Vinythai | http://www.vinythai.co.th/ |
| Foam Producer Examples | |
| 3A Composites | http://www.airexbaltekbanova.com/about-us.html |
| Airex AG | http://www.airexag.ch/en/products.html |
| DIAB Group | http://www.diabgroup.com/ |
| Vestolit | http://www.vestolit.de/vestolit-en/ |
5.13.2.9. Property Tables of Dense Fossil Polyvinyl Chloride
Table 5.67 relates to examples only and cannot be generalized (see also Table 5.66 for foam properties). Data cannot be used for design purposes. These results are not necessarily representative of all the fossil PVC and bio-PVC. These general indications should be verified by consultation with the producer of the selected grades and by tests under operating conditions.
Table 5.67
Dense PVCs (Polyvinyl Chloride): Examples of Properties
| PVC | PVC-HI | Rigid Compounds | |
| Miscellaneous Properties | |||
| Density (g/cm3) | 1.38 | 1.34 | 1.35–1.5 |
| Shrinkage (%) | 0.1–0.6 | ||
| Absorption of water (%) | 0.04–0.4 | ||
| Mechanical Properties | |||
| Shore hardness, D | 84 | 82 | 65–90 |
| Rockwell hardness, M | 47 | 39 | <10–70 |
| Rockwell hardness, R | 115 | 105 | 50–120 |
| Stress at yield (MPa) | 55 | 45 | 35–50 |
| Tensile strength (MPa) | 53 | 33 | 35–60 |
| Elongation at break (%) | 20–40 | 40–120 | 2–80 |
| Tensile modulus (GPa) | 3 | 2.2–3 | 2.4–4 |
| Flexural strength (MPa) | 103 | 67 | |
| Flexural modulus (GPa) | 3 | 3 | 2.1–3.5 |
| Notched impact strength ASTM D256 (J/m) | 54 | 20–110 | |
| Thermal Properties | |||
| Heat distortion temperature (HDT) B (0.46 MPa) (°C) | 57–80 | ||
| HDT A (1.8 MPa) (°C) | 70 | 70 | 54–75 |
| Vicat softening point B50 (°C) | 83 | 81 | |
| Continuous use temperature (°C) | 60 | 60 | 50–80 |
| Glass transition temperature (°C) | 60–100 | ||
| Minimum service temperature (°C) | −10 to 0 | ||
| Thermal conductivity (W/m K) | 0.15 | 0.15 | 0.16 |
| Specific heat (cal/g/°C) | 0.2–0.3 | ||
| Coefficient of thermal expansion (10−5/°C) | 7–9.5 | 7–9.5 | 5–18 |
| Electrical Properties | |||
| Volume resistivity (ohm cm) | 1015–1016 | 1015 | 1015–1016 |
| Dielectric constant | 3–4 | 3–4 | 3–4 |
| Loss factor (10−4) | 25–250 | 25–250 | 100–200 |
| Dielectric strength (kV/mm) | 50 | 40 | 10–40 |
| Arc resistance (s) | 60–80 | ||
| Fire Behavior | |||
| Oxygen index | 45 | ||
| UL94 fire rating | V0 | ||
| 10% GF | 30% GF | 30% GF HI | |
| Miscellaneous Properties | |||
| Density (g/cm3) | 1.43 | 1.57 | 1.53 |
| Shrinkage (%) | 0–0.1 | 0–0.1 | 0–0.1 |
| Mechanical Properties | |||
| Shore hardness, D | 86 | 89 | 87 |
| Rockwell hardness, M | 53 | 65 | 57 |
| Rockwell hardness, R | 118 | 118 | 110 |
| Tensile strength (MPa) | 73 | 97 | 80 |
| Elongation at break (%) | 6 | 2 | 3.5 |
| Tensile modulus (GPa) | 4 | 9 | 6.9 |
| Flexural strength (MPa) | 123 | 159 | 114 |
| Flexural modulus (GPa) | 4.5 | 8.3 | 6.6 |
| Notched impact strength @ 20°C ASTM D256 (J/m) | 43 | 60 | 97 |
| Notched impact strength @ −40°C ASTM D256 (J/m) | 38 | 50 | 70 |
| Thermal Properties | |||
| HDT A (1.8 MPa) (°C) | 75 | 76 | 75 |
| Thermal conductivity (W/m K) | 0.35 | ||
| Specific heat (cal/g/°C) | 0.25 | ||
| Coefficient of thermal expansion (10−5/°C) | 3.6 | 2.2 | 2.5 |
| Electrical Properties | |||
| Volume resistivity (ohm cm) | 1015 | ||
| Dielectric constant | 3.4 | ||
| Fire Behavior | |||
| UL94 fire rating | 5 V to V0 | 5 V to V0 | 5 V to V0 |
| Flexible Compounds | |||
| Plasticized | Plasticized and Filled | ||
| Miscellaneous Properties | |||
| Density (g/cm3) | 1.15–1.35 | 1.30–1.9 | |
| Shrinkage (%) | 0.8–5 | 0.2–1 | |
| Absorption of water (%) | 0.15–0.75 | 0.2–1 | |
| Mechanical Properties | |||
| Shore hardness, A | 55 to >96 | 55 to >96 | |
| Shore hardness, D | <10–70 | <10–70 | |
| Table Continued | |||
| Flexible Compounds | |||
| Plasticized | Plasticized and Filled | ||
| Rockwell hardness, M | <5 | <5 | |
| Rockwell hardness, R | <20–67 | <20–67 | |
| Tensile strength (MPa) | 10–25 | 7–25 | |
| Elongation at break (%) | 200–500 | 100–400 | |
| Thermal Properties | |||
| Heat distortion temperature (HDT) B (0.46 MPa) (°C) | <56 | <56 | |
| HDT A (1.8 MPa) (°C) | <53 | <53 | |
| Continuous use temperature (°C) | 50–80 | 50–80 | |
| Glass transition temperature (°C) | −50 to −5 | −50 to −5 | |
| Minimum service temperature (°C) | −40 to −5 | −40 to −5 | |
| Thermal conductivity (W/m K) | 0.16 | 0.16 | |
| Specific heat (cal/g/°C) | 0.3–0.5 | 0.3–0.35 | |
| Coefficient of thermal expansion (10−5/°C) | 7–25 | 5–20 | |
| Electrical Properties | |||
| Volume resistivity (ohm cm) | 1010–1016 | 1010–1016 | |
| Dielectric constant | 3–5 | 3–5 | |
| Loss factor (10−4) | 25–1600 | 25–1600 | |
| Dielectric strength (kV/mm) | 10–30 | 10–30 | |
| Fire Behavior | |||
| Oxygen index | 21–39 | 21–39 | |
| General chemical properties are subject to the compatibility of the fillers and reinforcements with the ambient conditions. If the fillers are well adapted, the chemical properties are the same for filled and neat polymers. | |
| The chemical resistance of flexible PVC can be strongly reduced and the absorption of water can be definitely higher. | |
| Light | UV stabilizers are needed |
| Dilute acids | Good behavior |
| Dilute bases | Good behavior |
| Strong bases | Good behavior |
| Solvents | Good behavior with aliphatic hydrocarbons |
| Attacked by aromatic hydrocarbons, chlorinated solvents, esters, ethers, and ketones. Variable resistance to oils, greases, alcohols | |
| Food contact | Possible for special grades |
As previously said, renewable PVC resins are claimed having properties and characteristics of the same order as homologous fossil PVC resins and can be processed by clients’ equipment without the need for any drastic adjustments. The previous information deals with general properties of fossil PVC resins and, of course, some properties of renewable grades can be different.
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