Poly alkyl vinyl

As shown in Table 3, the glass-transition temperatures of the amorphous straight-chain alkyl vinyl ether homopolymers decrease with increasing length of the side chain. Also, the melting points of the semicrystalline poly(alkyl vinyl ether)s increase with increasing side-chain branching. 

Poly(alkyl vinyl ether) CAS Registry Number T/C Mp, °C... 

Typical of these materials are the poly(vinyl thioethers), the poly(vinyl isocyanates), the poly(vinyl ureas) and the poly(alkyl vinyl ketones). Methyl isopropenyl ketone and certain vinylpyridine derivatives have been copolymerised with butadiene to give special purpose rubbers. 

G. Natta, G. Allegra, I. W. Bassi, C. Carlini, E. Chiellini, G. Montagnoli. Isomorphism phenomena in isotactic poly(4-methyl-substituted a-olefins) and in isotactic poly(alkyl vinyl ethers) , Macromolecules 2, 311 (1969). 

The selectivity of the Complex Formation is a very interesting subject, y - Cyclodextrin, (y - CD) has been found to form inclusion complexes with poly (methyl vinyl ether) (PMVE), poly(ethyl vinyl ether) (PEVE), and poly(n- propyl vinyl ether) (PnPVE) of various molecular weights to give stoichiometric compounds in crystalline states. However, a- cyclodextrin (a - CD) and (3 - Cyclodextrin ((3- CD) did not form complexes with poly (alkyl vinyl ether)s of any molecular weight, y -CD did not form complexes with the low molecular weight analogs, such as diethyl ether and trimethylene glycol dimethyl ether. 

Scheme 4.2 shows the chemical structures of the poly (alkyl vinyl ether)s [47] reported. 

Scheme 4.2 Poly (alkyl vinyl ether)s. (From ref. [47])...

Table 4 shows typical reaction conditions and results of the living cationic polymerization of isobutyl vinyl ether (IBVE) with the HCl/ZnCh [127] and the CFjCC H/ZnCL [227] initiating systems. The former system is now among the most convenient for the synthesis of poly(alkyl vinyl... 

C-7 1 values of isotactic-rich poly(alkyl vinyl ether)s (alkyl = CH3, C2H5, W0-C3H7, W0-C4H9, /-C4H9) were measured in toluene at 110°C and 100 MHz.319 The T values for syndiotactic sequences are consistently larger than those for isotactic sequences, in contrast to the cases of polymethacrylates and polypropylenes mentioned above. The NOE values for the polymers of methyl and /-butyl vinyl ethers are close to the theoretical maximum. These results indicate that the syndiotactic sequences have higher mobility than the isotactic sequences. 

Poly(l-alkoxyethylene) Poly(alkyl vinyl ether) -[ROCHCH ]-Poly(l-hydroxyethylene) Poly (vinyl alcohol) -[HOCHCH ]-Poly(l-alkanoylethylene) Poly(alkyl vinyl ketone) -[RCOCHCHJ... 

Mixtures of hydrocoUoidal gelling agents in an aqueous medium have also been employed as water-soluble or water-dispersible additives to provide gels having solids-suspending properties. Such mixtures include a mixture of hydroxypropyl-cellulose and poly(l-alkene-maleic anhydride) as poly(isobutylene-co-maleic anhydride), and a blend of hydroxypropylcellulose and poly(alkyl vinyl ether-co-maleic anhydride) as poly(methyl vinyl ether-co-maleic anhydride) [91]. 

Poly(alkyl vinyl athars). The initiation of vinyl ether polymerization with HI-I2 jdelds poljuners with narrow molecular weight distribution (198-200). 

Several other functionalities were also introduced to poly(alkyl vinyl ethers) by living carbocationic polymerization (Table 6). 

Table 6. Telechelic Poly(alkyl vinyl ethers)...

Phosphorus trichloride and phosphoryl chloride react with poly(alkyl vinyl ketones) in chloroform solution at room temperature to produce black polyenic conducting polymers, which are believed to contain structures like (Ifi). " ... 

A wide variety of anionic initiators [352] can also affect the polymerization of vinyl ketones. Crystalline poly(alkyl vinyl ketones) were prepared by precipitation polymerization using metallic lithium or alkyl lithium catalysts. Thomas [342] reported that lithium dust initiation at — 25°C produced two types of poly(isopropyl vinyl ketone). The ether-soluble crystalline fraction was unstable. The highest crystalline samples melted to a... 

Poly(alkyl methacrylates-co-MA), grafted on poly(ethylene-co-vinyl acetate), 466 Poly(alkyl vinyl ether-alt-MA) applications patents, 621 grafting to polybutadienes, 676 optically active, 317... 

J. Chen, M. Asano, T. Yamaki and M. Yoshida, Preparation of sulfonated cross-linked PTFE-gra/l-poly(alkyl vinyl ether) membranes for polymer electrolyte membrane fuel cells by radiation processing, J. Membr. Sci. 256, 38 (2005). 

If now, a stereoregular polymer undergoes a chemical reaction or interaction, it will be difficult to explain optical activity changes because chemical reactions perturb not only the chromophores but also the local conformations of monomeric units and, consequently, the macromolecular conformations. There is only a few synthetic stereoregular optically active polymers the optical activity of which has been followed during a chemical reaction. The more elaborated example is surely the complexation of stereoregular optically active poly alkyl vinyle the rs by tri-isobutyl-aluminium [31] ... 

Although they are mainly studied in Section 3.4 it is important to mention substitutions involving two groups of a chain at the same time. Examples are the acetalization of PVA, shown in reactions (22) and (23) and the formation of conjugated structures. The reaction of phosphorous trichloride with poly(alkyl vinyl ketones) leads to C=C, C=0 conjugated structures as a result of reaction (24). 

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