Chlorinated polyethylene applications

Chlorinated poly (vinyl chloride) (CPVC) has increased Tg compared to PVC, and this increases its upper use temperature. Applications include hot- and cold-water pipe as well as pipe for the handling of industrial chemical liquids. Chlorinated polyethylene (CPE) finds use as roofing and other vapor barrier membranes, as pond liners, and as an additive to improve the impact strength of PVC. 

Chlorinated polyethylene Chlorinated polyethylene Chloropoly- ethylene CM Not applicable Not applicable CE U6- 135 50-90 20 350 261... 

Small amounts of other polymers are used in certain niche applications, including chlorinated polyethylene (CPE), neoprene, chlorosulfonated polyethylene, nylon, and TPU. 

Application of this method for miscibility studies of blends of ethylene-vinyl acetate copolymer (45 wt.- % Ac) with chlorinated polyethylene (52 wt.- % Cl) at a constant frequency of 37 Hz is demonstrated in Fig. 13. The method has shown single T s for the blends studied. The Maxwell-Winger-Sillars conductivity effect which appears after the glass transition temperatures is also shown in this Figure. 

A few plastics which tend to be naturally brittle require an improvement in both their drop (impact) strength and their top loading (compression) strength. In the case of polystyrene, rubber is widely used as an impact modifier. Rigid PVC, particularly when used as a container, may suffer weakness when subjected to, say, a 3 4 foot drop test. Up to 15% of methyl methacrylate butadiene styrene (MBS) copolymer is usually added to improve impact strength. Chlorinated polyethylene has more recently been introduced as a PVC impact modifier. Vinyl acetate is frequently used as a modifier for PVC film. Polythene, LDPE-HOPE can have resistance to stress (environmental stress cracking), improved by the use either of rubber or polyisobutylene. These modifications have not as yet had any pharmaceutical applications. 

Unplasticized PVC present some processing difficulties due to its high melt viscosity in addition, the finished product is too brittle for some applications. To overcome these problems and to produce toughening, certain polymeric additives are usually added to the PVC. These materials, known as impact modifiers, are generally semicompatible and often some what rubbery in nature [14]. Among the most important impact modifiers in use today are butadiene-acrylonitrile copolymers (nitrile rubber), acrylonitrile-butadiene-styrene (ABS) graft terpolymers, methacrylate-butadiene-styrene (MBS) terpo-lymers, chlorinated polyethylene, and some polyacrylates. 

As already mentioned, most of the vessels concerned were in the chlorine production areas, but there are also some in the HCl recycling plant, the chlorinated polyethylene (Tyrin ) plant and also the glycerine and methylene diisocyanate plants. The most common application area was in acidic low pH media (37% of all the vessels) whereas 23% were in high pH caustic service, 27% were in neutral pH applications and the final 13% have been classified as mixed organic and inorganic streams. 

Chlorinated polyethylene (CPEy PEC). With a chlorine content to 25 to 40%, its most important applications are in PVC as an impact modifier and in technical rubber goods. Trade names Dow CPE (USA), Hostalit Z (FRG), Hostapren (FRG). 

Uses of Chlorinated Polyethylene Vulcanizates. CM is used in applications where aging resistance in hot air, oils, or chemicals is required and where good ozone, weathering, and flame resistance are required. Many such applications are in the wire and cable industry. 

The recent proliferation of metallocene-based polyolefins and polyolefin elastomers have gained their popularity owing to their density, cost, and ease of processabUity. PVC/POE blends have therefore been investigated as flexible PVC compounds. However, these blends are thermodynamically immiscible and needed suitable compatibiUzers such as the chlorinated polyethylenes (Eastman and Dadmun 2002). Since they are not miscible, POEs do not lower the PVC modulus sufficiently unless some plasticizer or a compatible elastomer such as EPE is also added. Commercially, some PVC/POE alloys are offered by TeknorApex under Flexalloy trade name with a shore A hardness 40-60 and brittle points down to —50 °C. They are claimed to have excellent low-temperature toughness, flexibility, compression set-resistance, and oil resistance. Suitable applications include automotive hoses, seals, gaskets, wire jacketing, etc. 

Chlorinated polyethylene (CPE). Chlorinated polyethylene modifiers are most commonly used in pipe, fittings, siding, and weatherable profiles. CPE modifiers compete primarily with acrylics in siding applications. CPE can be used in resins other than PVC, for example, PE and PP. 

Another type of TPU/Polefinic blend that has been evaluated is the chlorinated polyethylene (CPE)/TPU blend, which is limited to TPUs that have low thermal processing temperature (<200°C) because of the thermal instability of CPE. The use of small amounts of CPE improve processing and mold release properties of TPU while small amounts of TPU in CPE result in good strength properties and processing characteristics [53], These blends can be used in applications where fire-retardant characteristics and/or low temperature flexibility of the materials are required. 

PMMA/PVC blends provide heat resistance and chemical and flammability resistance into materials for injection moulding and extrusion applications. The major applications of these blends are interior panelling, trim and seat backs in mass transit vehicles. Commercially available PMMA is miscible with PVC [28, 31]. However, its phase behaviour is considered to be only partially miscible [29]. Chlorinated polyethylene blends with PVC have been used as impact modifiers and as secondary plasticisers [32], Chlorine contents of 42% and 30% by weight lead to miscible and immiscible properties, respectively. Impact modification will generally require phase separation, and plasticisation will require miscibility. 

Plastomer modification of PP continues to progress. Current work in many development laboratories focuses on modification of reactor TPOs to make soft flexible compounds for extruded or calendared sheet. In many such applications flexible PP sheets would replace plasticized polyvinyl chloride (PVC) or PVC blends, chlorinated polyethylene, or EPDM. 

Poly(vinyl chloride) + poly(vinyl chloride-co-acrylate), PVC + VC/A poly(vinyl chloride) + chlorinated polyethylene, PVC + PE- C, poly( vinyl chloride) + poly(acrylonitrile-co-butadiene-co-acrylester), PVC + ASA. Applications semifinished goods, foils, plates, profiles, pipes, fittings, gutters, window frames, door frames, panels, housings, bottles, blow molding, disks, blocking layers, fibers, fleeces, nets. 

A more positive aspect of the chemical functionality of PHB is that the polymer can act as a processing acid for other polymers such as PVC and polyacrylonitrile. Both PHB homopolymer and the HB-HV copolymers reduce the gelation time and improve the surface finish of extrudates when blended with unplasticized PVC at the 1% level prior to processing. They function in much the same way as high molecular weight polyacrylates and chlorinated polyethylene, which are already used commercially in this application. In addition, the power required to melt-extrude polyacrylonitrile-based resins, such as the Barex range from Lonza AG, is much reduced by the addition of 1% PHB to the polymer. 

Because of its structure, PVC is particularly sensitive to heat and is by far the largest user of heat stahilizers. Other vulnerable polymers are chlorinated polyethylene and PVC/ABS blends. The increasing use of engineering plastics in applications involving prolonged exposure to heat also calls for special stabilizer systems. 

To achieve good toughness, required for many applications, impact modifiers are added to PVC. Chlorinated polyethylenes, ethylene-vinyl acetate copolymers, styrene-methyl methacrylate grafted elastomers, vinyl rubbers, and polyacrylates are the most frequently used (316). These polymers are blended together with other additives. Blending conditions are extraordinary important for morphology control and consequently for final properties of the blends. 

Some specific recent applications of the chromatography-mass spectrometry technique to various types of polymers include the following PE [130, 131], poly(l-octene), poly(l-decene), poly(l-dodecene) and 1-octene-l-decene-l-dodecene terpolymer [132], chlorinated polyethylene [133], polyolefins [134,135], acrylic acid, methacrylic acid copolymers [136, 137], polyacrylate [138], styrene-butadiene and other rubbers [139-141], nitrile rubber [142], natural rubbers [143,144], chlorinated natural rubber [145,146], polychloroprene [147], PVC [148-150], silicones [151,152], polycarbonates (PC) [153], styrene-isoprene copolymers [154], substituted PS [155], polypropylene carbonate [156], ethylene-vinyl acetate copolymer [157], Nylon 6,6 [158], polyisopropenyl cyclohexane-a-methylstyrene copolymers [195], cresol-novolac epoxy resins [160], polymeric flame retardants [161], poly(4-N-alkylstyrenes) [162], pol)winyl pyrrolidone [31,163], vinyl pyrrolidone-methacryloxysilicone copolymers [164], polybutylcyanoacrylate [165], polysulfide copolymers [1669], poly(diethyl-2-methacryloxy) ethyl phosphate [167, 168], ethane-carbon monoxide copolymers [169], polyetherimide [170], and bisphenol-A [171]. 

Chlorinated polyethylene rubber or CPE is used extensively in critical hose and many cable applications. CPE imparts very good resistance to air aging, heat aging, ozone, and weathering. 

PVC with chlorinated polyethylene blends has improved impact performance, especially in the presence of notches and at lower temperatures than unmodified grades of PVC. They are used in continental Europe for external applications (e.g. rainwater goods) unmodified UPVC would be acceptable in the UK. Such blends are finding increasing use throughout Europe in extruded sections for window frames. 

Additional examples of the application of the Flory EOS to polymer blends include polystyrene/poly(vinyl methyl ether) [15,20,21], oligomeric polystyrene/polybutadiene [22], ethylene-vinyl acetate/chlorinated polyethylene [23], poly(e-caprolactone)/PVC [24], poly-(ether sulfone)/poly(ethylene oxide) [25]. 

SBS and SEBS block copolymers have been employed to impact modify HIPS, PPO/HIPS and various polyolefins. Maleic anhydride modified SEBS offers impact modification of polyamides and polyesters via reactive compatibilization. Chlorinated polyethylene (< 42 wt% Cl) is employed as an impact modifier for PVC, where weatherability is a primary concern [121]. Ethylene-(meth)acrylic acid copolymers and their neutralized versions (ionomers) have been utilized as impact modifiers for polyamides. PBT and PET impact modification with the poly(ester-ether block copolymer) (PBT-poly(tetramethylene oxide) (AB) ) yielded utility in automotive fascia applications. These products have been available under the tradenames Lomod (GE), Bexloy (duPont) andRiteflex (Hoechst-Celanese) [3]. 

Since little research had been reported on the application of thermal analysis (TA) methods to roofing, the committee recommended that more research be carried out to provide the technical basis for this application. The recommendation was based on research by Farlling and Backenstow and Flueler.I J These authors used TG, DSC, and DMA to characterize EPDM, PVC, and polymer-modified materials. Backenstow and Flueler reported the application of torsion pendulum analysis to characterize the above membrane materials. They concluded that TA techniques were useful for membrane characterization and should be investigated as methods for incorporation into standards. Previous work published by Cash on the use of DSC to characterize neoprene, chlorinated polyethylene (CPE) and PVC had shown that DSC could be used to identify not only the components in a single-ply sheet and the manufacturer, but also to differentiate between new and exposed materials. 

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