Poly vinyl ethers

Poly(vinyl alcohol) can be derived from the hydrolysis of a variety of poly(vinyl esters), such as poly(vinyl acetate), poly(vinyl formate), and poly(vinyl ben2oate), and of poly(vinyl ethers). However, all commercially produced poly(vinyl alcohol) is manufactured by the hydrolysis of poly(vinyl acetate). The manufacturing process can be viewed as one segment that deals with the polymeri2ation of vinyl acetate and another that handles the hydrolysis of poly(vinyl acetate) to poly(vinyl alcohol). 

More recent examples include end-functionalized multiarmed poly(vinyl ether) (44), MVE/styrene block copolymers (45), and star-shaped polymers (46—48). With this remarkable control over polymer architecture, the growth of future commercial appHcations seems entirely likely. 

Table 3. Glass-Transition Temperature of Amorphous Poly(Vinyl Ether)s and Melting Points of Crystalline Poly(Vinyl Ether)s ...

The poly(vinyl ethers), whieh were first made available in Germany before 1940, are not of importance in the plastics industry but have applications in adhesives, surfaee coatings and rubber technology. Of the many vinyl ether polymers prepared, only those from the vinyl alkyl ethers and some halogenated variants are of interest. Two methods of monomer preparations may be used. 

A number of higher poly(vinyl ether)s, in particular the ethyl and butyl polymers, have found use as adhesives. When antioxidants are incorporated, pressure-sensitive adhesive tapes from poly(vinyl ethyl ether) are said to have twice the shelf life of similar tapes from natural rubber. Copolymers of vinyl isobutyl ether with methyl acrylate and ethyl acrylate (Acronal series) and with vinyl chloride have been commercially marketed. The first two products have been used as adhesives and impregnating agents for textile, paper and leather whilst the latter (Vinoflex MP 400) has found use in surface coatings. 

Poly(vinyl ethers) 1928 1936 Adhesives, plasticizers Poly(chloroprene) 1925 1932 Elastomers... 

Since these reports, a number of new approaches based on vinyl monomers and various initiating systems have been explored to yield hyperbranched polymers such as, poly(4-acetylstyrene) [26], poly(vinyl ether) [27] and polyacrylates [28], In view of the fact that free radical polymerizations are most widely used in industrial polymerization processes the development of these procedures for vinyl monomers has opened a very important area for hyperbranched polymers. 

Gantrez Poly(vinyl ether-comaleic anhydride) General Aniline Film... 

Lutonal Poly(vinyl ethers) Badische Anilin Soda-Fabrik AG... 

M. Sawamoto, T. Enoki, and T. Higashimura, End-functionalized polymers by living cationic polymerization. 1. Mono- and bifunctional poly(vinyl ethers) with terminal malonate or carboxyl groups, Macromolecules, 20(l) l-6, January 1987. 

The second method is the most widely used to prepare optically active vinyl polymers (poly-a-olefins, poly-vinyl-ethers, polyacrylic esters and amides etc.. ... 

Highly isotactic fractions have lower melting points than poly-a-olefins having analogous structure, as observed in other poly-vinyl-ethers (26). 

In spite of the above relationships between absolute structure of the monomer and sign of the rotatory power of the polymer, which are consistent with what has been found in poly-a-olefins, the relationships between optical rotation and structure in poly-vinyl-ethers are much more complicated than in the paraffins. 

As in the case of poly-a-olefins, only in some poly-vinyl-ethers in which the asymmetric carbon atom of the lateral chains is in the ft position with respect to the principal chain and in which the optical activity is remarkably higher than in low molecular weight models, it was found that the optical activity and its temperature coefficient remarkably depend on the stereoregularity of the sample. 

The optical activity of poly-vinyl-ethers, in the few cases investigated (22), does not appear to be dependent on the concentration of the solution, but it changes remarkably depending on the type of solvent (Table 14). 

Interesting results have been observed by investigating complexes of some poly-vinyl-ethers with tri-isobutyl aluminum. It was noticed that the variation of the optical activity on complexing poly-vinyl-ethers with tri-isobutyl aluminum is of the same type as in the low-molecular-weight model compounds (66, 111, 113b, 123). 

In fact, in poly-acrylates the closest position of the asymmetric carbon atom of the lateral chains, with respect to the principal chain, is the y-position (XXV) while, as we have already noted in the case of poly-a-olefins and poly-vinyl-ethers, the greatest differences between the rotatory power of polymers and low-molecular-weight models occur when the asymmetric carbon atom is in a (XXVI) or in S (XXVII)... 

In agreement with the data on poly-a-olefins and poly-vinyl-ethers having the side chain asymmetric carbon atoms in the y-position with respect to the main chain, stereoregularity does not exert a remarkable influence on the rotatory power of poly-acrylates and poly-methacrylates. In fact, according to the quantitative data reported by H. Sobue, K. Matsuzaki, S. Nakano (135), and to the qualitative indications given by Liu, Szuty and Ullmann (64), concerning respectively poly-menthyl-meth-acrylate and poly-(l-methyl-benzyl)-methaciylate, the specific optical activity of the polymers does not vary by more than 30% when varying, within a wide interval, the isotactic triads content of the polymers (Table 18). 

Both in poly-a-olefins and in poly-vinyl-ethers, which are the most systematically investigated optically active vinyl polymers, the chromo-phoric systems responsible for the optical activity appear to be in the same spectral region of those of the low-molecular-weight models 66. 105,113a). 

The above considerations cannot be extended at the present to the poly-vinyl-ethers as no suitable methods are available to calculate the optical activity of the low-molecular-weight ethers and hence of the polymer monomeric unit. 

Besides melittin, Rozema and colleagues took advantage of the lytic activity of poly(vinyl ether) composed of butyl and amino vinyl ethers (PBAVE). They designed Dynamic PolyConjugates by developing an elegant strategy for... 

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