Polyvinylchloride, flexible

Fig. 2 Compression set (elastic recovery under compressive deformation) at 70 °C for an ethyl-ene-LAO random copolymer, flexible polyvinylchloride (f-PVC) thermoplastic polyurethanes (TPUs), and thermoplastic vulcanizates (TPVs)...

The ability to make PE with properties that fall outside these limitations would lead to a tremendous expansion of uses for this polymer, for example replacing flexible polyvinylchloride (f-PVC), which cannot be incinerated or recycled, thermoplastic polyurethanes (TPUs), or thermoplastic vulcanates (TPVs). 

ISO 6453-85 Polymeric Materials, Cellular Flexible —Polyvinylchloride Foam Sheeting — Specification, 9 pp... 

PVDF polyvinylidine fluoride ETPU engineering thermoplastic polyurethane POP poly(oxyethylene glycol) polymer FPVC flexible polyvinylchloride Conv. conventional ... 

Elastic memory of the differences in shear history between material in the centre and outer screw channel regions may contribute to ripples in clear flexible polyvinylchloride sheet [11] and cause other rheological defects. 

A repeat was made of the experiment described in Section 2.3.4.2, in which clear flexible polyvinylchloride (PVC) was extruded with a 38 mm extruder and a striation of flexible black PVC was injected from a 25 mm extruder through a transducer port just before the mixer entry. Following stabilisation of extrusion conditions the extruder was stopped, the 8 mm strand die removed and the rotor and stator removed... 

To illustrate this relationship, consider a random ethylene copolymer of a density 0.856gcm" containing 19mol.% 1-octene comonomer. At room temperature, the material is elastic, or capable of recovering its size and shape after deformation. However, the copolymer loses the desirable properties of an elastomer at higher temperatures for example, the material has a compression set, a measure of a material s ability to recover its size after compression, of 100% at 70 °C (Figure 2). The ability to make PE with properties that fall outside these limitations would lead to a tremendous expansion of uses for this polymer, for example, replacing flexible polyvinylchloride (f-PVC), which cannot be incinerated or recycled, or more expensive thermoplastic polyurethanes (TPUs) or thermoplastic vulcanizates (TPVs). 

Figure 2 Compression set (elastic recovery under compressive deformation) at 70 °C for an E-LAO random copolymer, flexible polyvinylchloride (f-PVC), thermoplastic polyurethanes (TPUs), and thermoplastic vulcanizates (TPVs). Reproduced with permission from Wenzel, T. T. Arriola, D. J. Carnahan, E. M. et at. In Metal Catalysts in Olefin Poiymerization. Topics in Organometallic Chemistiy, Guan, I., Ed. Springer-Verlag Berlin, Germany, 2009 Vol. 26. ...

A few years ago, an effort was made to develop a polyolefin-based elastomer as a replacement materials for certain toy applications. One particular development target was to develop a drop-in alternative to flexible polyvinylchloride (f-PVC) in certain parts that are currently injection molded. Relatively unsophisticated molding equipment is frequently used in the manufacture of these parts in certain areas of the world e.g. lack of reliable temperature control and mechanical ejector devices), and this imposes tighter constraints on any material that was to substitute for an incumbent material. For this reason, the materials developed for these applications had to not only adequately match the p ormance properties of the incunfbent materials but processing performance had to also be reasonably matched as well. 

As can be seen from Eq. (77), the quantity Aa is definitely not a constant but diould grow with an increase in chain flexibility (Le. decrease of 0). Thus, if both the SB relationship and our Eq. (76) are correct, the plot of Aa against 0 Aa should be a straight line with a slope of unity. And, indeed, Aa actually tends to increase with decrease of 0, but this behavior cannot be quantitatively accounted for by Eq. (77), as the deviations of the experimental points from the theoretical line become steadily more pronounced as Aa decreases. The best fit of experimental values of Aa is observed only for those polymers which exactly conform to the SB rule (polyvinylchloride, polyvinylacetate, etc.). This result emphasizes once more that the value of fg as defined earlier is not a constant, at least for the many varieties of polymers. To gain a deeper insight into the expected relationship between Aaand 0, we plotted lg Aa against 0 Aa. In this case much better linear dependence clearly results, with the experimental points fluctuating around the theoretical line even for those polymers which do not obey the SB rule. 

HCN) from polyacrylonitrile or hydrogen chloride (HC1) from polyvinylchloride. Another hazard presented by plastics results from the presence of plasticizers added to provide essential properties, such as flexibility. The most widely used plasticizers are phthalates (see Chapter 14), which are environmentally persistent, resistant to treatment processes, and prone to undergo bioaccumulation. 

Polyvinylchloride (PVC) is a hard, amorphous polymer which softens at about 85 °C. Also in PVC rubbers are sometimes added in order to improve the impact strength. The main applications of PVC are pipes, gutters, front panels of buildings, cables, bottles, floor tiles. A much softer and more flexible material is obtained by blending with plasticizers soft or plasticized PVC is being used in artificial leather, tubes and hoses, footwear, films, etc. 

PVC (Polyvinylchloride) HC6511 Clear, very flexible, comes in varying degrees of durometer hardness. Excellent resistance to water and oxidation. Contains plasticizers (if leached out, will cause tubing to harden). 

The major use of vinyl chloride (also known as vinyl chloride monomer, VCM) is in the production of the ubiquitous plastic, PVC or polyvinylchloride, which began to be used in the 1940s. This polymer is used in a wide variety of products ranging from cling film, bottles, car components, pipes, electrical insulation, and window frames. Unfortunately, vinyl chloride, which is used to make the plastic, is a hazardous chemical. For this reason and because PVC is an organochlorine compound, it has received a bad press. It has important properties, however, such as flexibility, toughness, and durability, that make it an extremely useful and versatile material. 

AMS 3569A-88 Foam, Flexible Polyurethane (PUR), Open Pore, Polyvinylchloride Coated, 9 pp... 

Plasticizers (e.g., phthalate esters and p-nonylphenol) were introduced to impart flexibility to polyvinylchloride (PVC) and other plastics. Their developmental effects on children were subsequently discovered. 

Polyvinylchloride is rigid, transparent and, although it lacks the sparkle of poly styrene, is less brittle. Drop strength can be improved by the use of an impact modifier such as vinyl acetate or methyl methacrylate butadiene styrene (MBS). PVC is moderately permeable to moisture but has excellent resistance to oil and oxygen permeation. Plasticised PVC has high flexibility and is particularly useful when a collapsible pack is required. It is a poor barrier to moisture and a moderate barrier to gases, hence is usually overwrapped . 

Polyvinylchloride (PVC) is commercially the most signihcant member of the family of vinyl resins. The other important members of this group are chlorinated-PVC (CPVC) and polyvinylidene chloride (PVDC). PVC is one of the most widely used, commodity type thermoplastics with an annual consumption of over 5 Mton/y in the USA. The excellent versatility of PVC is attributed to its blending capability with a variety of plasticizers, additives and fillers to yield products ranging from very flexible to very rigid types. In addition, PVC has a low cost advantage and a reasonably good balance of properties, which... 

Polyvinylchloride (PVC) coating is widely used for its barrier function together with PET fabric. It is essentially a hard polymer, but its hardness, and thus its flexibility, may be varied by the addition of softeners. However, softeners pose a problem because they can volatilise during use, thus leaving PVC in a hard and brittle state with microcracks, where soil may collect and chemicals or water can get to the polyester. 

Acrylonitrile-butadiene rubber, NBR, styrene-aciylonitrile rubber, SAN, ethylene-vinyl acetate copolymer, EVA, and acrylic copolymers are helpful modifications of polyvinylchloride that change its processing characteristics and elastomeric properties. Blending with these copolymers helps to reduce the requirement for low molecular weight plasticizers. Ethylene-vinyl acetate copolymer plays a role of high molecular weight plasticizer in production of vinyl hose. This reduces the amount of DOP used in flexible hose applications. Ethylene copolymer is used plasticize PVC that reduces gel. "" Phthalate plasticizers can be eliminated from water based adhesives because of utilization of vinyl acetate ethylene copolymer as a high molecular plasticizer/modifier. " ... 

Polyvinylchloride is very popular in flame resistant applications because of its intrinsic protection due to its high content of chlorine (57%). At the same time, PVC is a rigid material and requires plasticizers to produce flexible articles. Addition of plasticizers reduces chlorine content and some form of enhancement of flame retardancy is required. Chloroparaffins were commonly used as secondary plasticizers due to their very high chlorine content (up to 70%) but some chloroparaffins are now on the hsts of restricted... 

Thermoplastic polymers These may be repeatedly warmed and cooled without appreciable changes occurring in the properties of the material. They are good insulators, but give off toxic fumes when burned. They have a flexible quality when operated up to a maximum temperature of 70"C but should not be flexed when the air temperature is near 0 C, otherwise they may crack. Polyvinylchloride (PVC) used for cable insulation is a thermoplastic polymer. 

Many of the hazards from the polymer industry arise from the monomers used as raw materials. Many monomers are reactive and flammable, with a tendency to form explosive vapor mixtures with air. All have a certain degree of toxicity vinyl chloride is a known human carcinogen. The combustion of many polymers may result in the evolution of toxic gases, such as hydrogen cyanide (HCN) from polyacrylonitrile or hydrogen chloride (HCl) from polyvinylchloride. Another hazard presented by plastics results from the presence of plasticizers added to provide essential properties such as flexibility. The most widely used plasticizers are phthalates, which are environmentally persistent, resistant to treatment processes, and prone to undergo bioaccumulation. 

It is said that polyvinylchloride is a particular polymer which can be continuously transformed from rigid-state to flexible-state with a proper quantity of plasticizer which is necessary to be used in itself. However, plasticizer is essentially apt to bleed out and is not so good for the physical nature after long periods of outdoor exposure. 

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