Homopolymers early research

The first commercially available acetal resin was marketed by Du Pont in 1959 under the trade name Delrin after the equivalent of ten million pounds had been spent in research or polymers of formaldehyde. The Du Pont monopoly was unusually short lived as Celcon, as acetal copolymer produced by the Celanese Corporation, became available in small quantities in 1960. This material became commercially available in 1962 and later in the same year Farbwerke Hoechst combined with Celanese to produce similar products in Germany (Hostaform). In 1963 Celanese also combined with the Dainippon Celluloid Company of Osaka, Japan and Imperial Chemical Industries to produce acetal copolymers in Japan and Britain respectively under the trade names Duracon and Alkon (later changed to Kematal). In the early 1970s Ultraform GmbH (a joint venture of BASF and Degussa) introduced a copolymer under the name Ultraform and the Japanese company Asahi Chemical a homopolymer under the name Tenal. 

Isobutylene has been of interest since the early days of synthetic polymer research when Friedel Crafts catalysts were used to prepare elastic materials. Isobutylene polymers of commercial importance include homopolymers and copolymers containing small amounts of isoprene or p-methylstyrene. Currently, chlorinated and brominated derivatives of butyl(poly[isobutylene-co-isoprene]) have the highest sales volume. 

Polymers with the repeat units -fCH - Of, known as polyacetals, have been known since the early 920 s. It was not until the late 1950 s, however, that research efforts resulted in high molecular weight linear, stable thermoplastic materials. Whereas these developments were directed towards homopolymers of formaldehyde at DuPont, the research at Celanese Corporation was aimed towards copolymers using trioxane, a cyclic formaldehyde trimer, as the major monomer. 

Soon after the development of polyacrylonitrile fibers by DuPont Company In the 1940 s, the remarkable thermal stability of this material was recognized. At the time, cellulosic fibers and FAN (homopolymer) fibers were the only fibrous substances which did not melt below their charring temperature and were, therefore, capable of retaining their fiber identity as carbon materials. Winter, of Union Carbide s National Carbon Co. Research Laboratories, Investigated DuPont s early FAN fibers as precursors for carbon fibers near the end of World War II some of these fibers had been thermally stabilized (apparently early versions of "black Orion ) by W. D. Coxe of DuPont [5]. 

For almost two decades following the early 1960s there had been relatively limited research activities on the rheology of branched flexible homopolymers. However, in 1988 McLeish (1988) extended the concept of the Doi-Edwards tube model, which had been developed for linear flexible homopolymers (see Chapter 4), to describe the dynamics of branched flexible homopolymers. Since then, during the past several years, other investigators (Blackwell et al. 2000 Bourrigaud et al. 2003, Inkson et al. 1999 McLeish and Larson 1998 McLeish et al. 1999 Shie et al. 2003 Verbeeten et al. 2001) have actively engaged in further development of this theory. Such efforts have... 

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