Injectable polymers poly chemical

The poly(vinyl acetal) prepared from acetaldehyde was developed in the early 1940s by Shawinigan Chemicals, Ltd., of Canada and sold under the trade name Alvar. Early uses included injection-molded articles, coatings for paper and textiles, and replacement for shellac. Production peaked in the early 1950s and then decreased as a result of competition from less expensive resins such as poly(vinyl chloride) (see Vinyl polymers, poly(vinyl chloride)). 

Because the physical and chemical properties of a number of injectable polymer hydrogels are pH and temperature dependent, a new copolymer of poly (A-isopropylacrylamide)-g-methylcellulose (PNIPAAm-g-MC) has been explored as a 3-D scaffold for AC regeneration. In this system, PNIPAAm has a lower critical solution temperature (LCST) of approximately 33°C and undergoes a liquid-to-gel reversible phenomenon while also having the added advantage of an LCST very close... 

In 2002, the world production of polymers (not including synthetic libers and rubbers) was ca. 190 million metric tons. Of these, the combined production of poly(ethylene terephthalate), low- and high-density polyethyelene, polypropylene, poly(vinyl chloride), polystyrene, and polyurethane was 152.3 milhon metric tons [1]. These synthetic, petroleum-based polymers are used, inter alia, as engineering plastics, for packing, in the construction-, car-, truck- and food-industry. They are chemically very stable, and can be processed by injection molding, and by extrusion from the melt in a variety of forms. These attractive features, however, are associated with two main problems ... 

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