Vinyl family

The vinyl family of polymers consists of poly(vinyl chloride), poly(vinylidene chloride), poly(vinyl acetate), and their copolymers and derived polymers. 

Vinyls are one of the most versatile families of plastics. The term vinyl usually identifies the major very large production of polyvinyl chloride (PVC) plastics. The vinyl family, in addition to PVCs, consists of polyvinyl acetals, polyvinyl acetates, polyvinyl alcohols, polyvinyl carbazoles, polyvinyl chloride-acetates, and polyvinylidene chlorides. As a family, they are strong and abrasion resistant. They are unaffected, for the most part, by prolonged exposure to water, common chemicals,... 

Owing to its versatility of application and low cost, PVC is one of the most widely used thermoplastics, and by far the most important member of the vinyl family. However, PVC is thermally unstable and difficult to process. To improve processability, the resin must be plasticized, stabilized and processed under strictly controlled conditions. The necessity to improve processability by incorporation of a permanent plasticizer was the main reason for blending PVC, in addition to the need to increase its HDT and impact strength. 

Acrylic adhesives first appeared about 1937 the acrylic resins may be considered as belonging to the vinyl family [1, p. 305], Today, acrylic adhesives appear in many forms as both pressure-sensitive and non-pressure sensitive formulations in organic solvent and emulsion forms as monomer and polymer cements as anaerobics as cyanoacrylates as so-called reactive or honeymoon two-part systems and as radiation curing formulations. Commercial production of acrylic polymers began in the late 1920s, but it was not until 1958 that the first aerylie sealant was developed [10, p. 226]. The solvent-based acrylic sealants were first introdueed to the eonstruction industry in about 1960 ... 

Plasticizers are quite varied for the vinyl family, depending on the type of vinyl polymer. Many plasticizers are known for PVB through decades of development trials. Plasticizers for PVA tend to be more limited in number. PVC similarly has few reported plasticizing agents.The function and types of plasticizers are addressed in detail in Section 2.5. It should be mentioned at this point, however, that atmospheric humidity can act as a plasticizer for PVA, which can have very major repercussions during post-cast processing. 

Analogously, poly(vinyl ketals) can be prepared from ketones, but since poly(vinyl ketals) are not commercially important, they are not discussed here. The acetalization reaction strongly favors formation of the 1,3-dioxane ring, which is a characteristic feature of this class of resins. The first of this family, poly(vinyl ben2al), was prepared in 1924 by the reaction of poly(vinyl alcohol) with ben2aldehyde in concentrated hydrochloric acid (2). Although many members of this class of resins have been made since then, only poly(vinyl formal) [9003-33-2] (PVF) and poly(vinyl butyral) [63148-65-2] (PVB) continue to be made in significant commercial quantities. 

Ethylene-vinyl acetate EVAs (in the polyolefin family) have exceptional barrier properties, good clarity and gloss, stress-crack resistance, low temperature toughness/retains flexibility, adhesion, resistance to UV radiation, etc. They have low resistance to heat and solvents. 

The rates of radical-forming thermal decomposition of four families of free radical initiators can be predicted from a sum of transition state and reactant state effects. The four families of initiators are trarw-symmetric bisalkyl diazenes,trans-phenyl, alkyl diazenes, peresters and hydrocarbons (carbon-carbon bond homolysis). Transition state effects are calculated by the HMD pi- delocalization energies of the alkyl radicals formed in the reactions. Reactant state effects are estimated from standard steric parameters. For each family of initiators, linear energy relationships have been created for calculating the rates at which members of the family decompose at given temperatures. These numerical relationships should be useful for predicting rates of decomposition for potential new initiators for the free radical polymerization of vinyl monomers under extraordinary conditions. 

We can incorporate short chain branches into polymers by copolymerizing two or more comonomers. When we apply this method to addition copolymers, the branch is derived from a monomer that contains a terminal vinyl group that can be incorporated into the growing chain. The most common family of this type is the linear low density polyethylenes, which incorporate 1-butene, 1-hexene, or 1-octene to yield ethyl, butyl, or hexyl branches, respectively. Other common examples include ethylene-vinyl acetate and ethylene-acrylic acid copolymers. Figure 5.10 shows examples of these branches. 

The most common copolymer of this type is ethylene-vinyl acetate, which we normally refer to as EVA. This variety of polyethylene is illustrated in Fig. 18.2 e), in which the ester branches are indicated by the symbol VA This family of copolymers is commercially available containing vinyl acetate concentrations of up to approximately 25 mole %. In addition to the randomly distributed ester branches, these resins also contain the short and long chain branches that are characteristic of low density polyethylene. 

Photolysis of acyldisilanes at A > 360 nm (103,104) was shown, based on trapping experiments, to yield both silenes 22 and the isomeric siloxy-carbenes 23, but with polysilylacylsilanes only silenes 24 are formed, as shown by trapping experiments and NMR spectroscopy (104,122-124) (see Scheme 4). These silenes react conventionally with alcohols, 2,3-dimethylbutadiene (with one or two giving some evidence of minor amounts of ene-like products), and in a [2 + 2] manner with phenyl-propyne. Ketones, however, do not react cleanly. Perhaps the most unusual behavior of this family of silenes is their exclusive head-to-head dimerization as described in Section V. More recently it has been found that these silenes undergo thermal [2 + 2] reactions with butadiene itself (with minor amounts of the [2 + 4] adduct) and with styrene and vinyl-naphthalene. Also, it has been found that a dimethylsilylene precursor will... 

Bogy o s group developed several ABPs for cysteine proteases with epoxide, vinyl sulfone, and acyloxymethyl ketone reactive groups [42,43]. Particularly noteworthy is DCG04 (4), a biotinylated papain-family protease inhibitor with an epoxide reactive group that targets... 

Santner H. J., Moller K. C., Ivanco J., Ramsey M. G., Netzer F. P., Yamaguchi S., Besenhard J. O., Winter M., Acrylic acid nitrile, a film-forming electrolyte component for lithium-ion batteries, which belongs to the family of additives containing vinyl groups, J. Power Sources, (2003) 119, 368-372. 

The principal field of application for synthetic polymers as art materials is that of paint binders, which developed in the second half of the twentieth century when manufacturers of artists paints and varnishes realized the potential of synthetic resins used in the decorative household and industrial paint market [81]. The most important families of synthetic artists paints are the acrylics, the vinyl acetate resins, and the alkyds, and Py-GC/MS has been used to identify all these types of modem paints. 

An elastomer of the silicone family (see Silicones). It is a polyorganosiloxane, the backbone structure consisting of alternating silicone and oxygen atoms with organic groups, usually methyl, vinyl or phenyl radicals, attached to the silicon member. 

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