VINYL HALIDE POLYMER

PVF is more thermally stable than other vinyl halide polymers. High molecular weight PVF is reported to degrade in an inert atmosphere, with concurrent HF loss and backbone cleavage occurring at about 450°C (71,72). In air, HF loss occurs at about 350°C, followed by backbone cleavage around 450°C. 

Fhenoxypropylene sulfide increases the resistance of vinyl halide polymers to deoompesition by light.88... 

Fhenoxypropy] te sulfide increases the Teeietanioe of vinyl halide polymers to decomposition by light. ... 

Johnston, E, Plastic composition comprising a vinyl halide polymer and a phosphorus containing compound as a plasticizer therefor. Union Carbide and Carbon, U.S. Patent Appl. US 2668800, 1954 Chem. Abstr, 48, 8586h, 1954. 

Derivatives of monohydroxybenzophenone which possess R = H, lower alkyl, or halogen, and finding use for the stabilization of vinyl halide polymers [9-13] derivatives containing normal or branched alkyl radicals with six carbon atoms or more are finding use for the stabilization of polyethylene [5]. 

This study was followed by a series of papers that examined the effect of the distance between the pendant fluorine [96], chlorine [97], or bromine [98] atoms. Later, a series of ethylene/vinyl halide polymers containing fluorine, chlorine, and bromine were created via ADMET copolymerization of a halogen-containing (x,K)-diene and 1,9-decadiene [99]. Thermal analysis of these statistically random copolymers showed a distinct difference between their crystallization behavior and that of their compositionally matched precise analogs. The sharp melting... 

As an example of the use of a polymer-bound reagent 228, the transformation of alkoxyallenes 8 into vinyl halides 229 is depicted in Scheme 8.57 [131]. 

Koshechko, V.G., Titov, V.E. and Sednev, D.V. (1994) New route for producing acrylic add copolymers, based on electrochemical carboxylation of poly(vinyl halide)s and polybutadiene. Polymer 35, 1787-1788. 

This result may also give a partial explanation for the known ozone stability of polymers containing vinyl halide moieties. Part of this inertness is undoubtedly the result of the slow ozone attack. However, this phenomenon can only impart a prolonged ozone resistance, while the conversion of the original double bond into single bonds could impart a permanent ozone resistance. We are extending our research to further model compounds of such polymer microstructures to find out whether... 

The initial interest in vinyl derivatives was due to their importance in the production of polymers. At present, however, vinyl halides are also widely used in organic syntheses as both precursors for the generation of nucleophilic reagents like vinyllithium or -magnesium derivatives, and as formal equivalents of the vinyl cations in couplings with various organocuprates (Scheme 2.51). 

The coordination of the functionalities that may be present either in the monomer or in the growing polymer chain to the metal center is one key impediment in the development of new transition metal-based catalysts for the insertion polymerization of polar monomers. On the other hand, rapid -halide abstraction has prevented metal-catalyzed polymerization of vinyl halides. Several examples are discussed to illustrate these problems. 

In SPOC, either the aryl or vinyl halide or the boronate can be bound to the polymeric support. In most cases however, the aryl halide is bound to the polymer. A wide range of coupling conditions were developed within recent years, which are compatible with many polymeric supports (polystyrene, polyacrylamide, PEG, etc.) and are tolerated by many functional groups. 

During 1928-32 compositions were made by dissolving polymers of vinyl halides in a number of high-boiling esters at elevated temperatures to form rubberlike materials. 

PoIy(vinyl halides) - Biodegradable PVC has been made by grafting sucrose acrylate to the surface of the polymer,while the effects of weathering have been examined on UPVC windows. Here comparable studies were undertaken in order to compare natural with artificial ageing conditions. 

As mentioned before, the monomer has a low boiling point ( - 72.2°C) and a relatively low critical temperature (54.7°C). For comparison, vinyl chloride has a boiling point of - 13.8°C and a critical temperature of 147°C (cf. this series, Vol. 11, 2nd ed., p. 358). Therefore the polymerization of vinyl fluoride is usually carried out under high-pressure conditions which probably resemble the polymerization of ethylene more than that of the other vinyl halides. The monomer is soluble in a variety of solvents. At room temperature, the homopolymer is insoluble. Therefore the neat subdivision of polymerization techniques into bulk, solution, suspension, and emulsion procedures which we have used in many other sections in this series becomes blurred. Most procedures seem to lead to blocks of polymer or some sort of dispersions from which... 

Qin, M. F. Head to Head Vinyl Polymers Head to Head Poly(vinyl halides) and Chiral Crystallization. Dissertation, Polytechnic University, 1995. 

Polyvinyl compounds are produced either by the polymerization of vinyl compounds CH2=CHX or by polymer analog reactions on polyvinyl compounds. The derivatives of poly(vinyl alcohol) -%CH2—CH(OHH- , poly(vinyl halides) -f-CH2—CHHal and poly-(vinyl amines) -%CH2—CH(NRiR2)- are of particular commercial importance. In contrast to these, poly(vinyl sulfides) -f-CH2—CH(SR)- are only of academic interest. Vinyl alcohol is unstable, since it transforms into acetaldehyde on formation. Therefore, poly(vinyl alcohol) is produced from poly(vinyl acetate). 

Some vinylphosphonates and allylphosphonates are slow to form homopolymers although they copolymerise well with vinyl halides, acrylonitrile, CH2=CH CN and acrylates CH2=CH COOH. A simple alternating polymer (A B A B -type) is indicated in (12.168). As in all copolymers however, there also arises the possibility of a block-type polymer - (A) (B) , (A) (B) - being formed. 

Polyisobutylene of low molecular weight was synthesized by a Wurtz type reaction from l,4-dibromo-2,2,3,3 tetramethylbutane. Polyacrylates were obtained from alternating copolymerization of symmetric internal olefins or ethylene with maleic anhydride followed by quantitative esterification. Poly(vinyl halides) were prepared from cis-1,4-polybutadiene by chlorination (H-H PVC) or bromin-ation (H-H PrBr). The polymers were characterized and their chemical, thermal, degradation solution, melt and blending behavior was studied. 

Arc resistance and electrical insulation, combined with low volatility, are mentioned for polyester-styrene polymers containing cured aminoplasts as fillers. Curable epoxy resins may replace the polyester-styrene compositions. Reinforced unsaturated polyester-styrene compositions with or other thermoplastic vinyl halide form a... 

The first halide-containing ADMET polymer was synthesized as a sequence-controlled ethylene-co-vinyl chloride polymer [94]. Later, a series of ADMET polymers containing pendant fluorine, chlorine, and bromine groups were synthesized [95]. These polymers allowed the effect of pendant defect size to be systematically studied. As expected, the larger the pendant atom, the lower the melting temperature and enthalpy. 

N.W. Johnston and H.J. Harwood, Intersequence cyclization reaction in methyl methacrylate - vinyl halide copolymers and terpolymers, Polym. Sci., Part C, No. 22 591 (1969). 

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