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Tham khảo tài liệu 'handbook of polymer synthesis second edition episode 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 7 Aromatic Polyethers Hans R. Kricheldorf Institute of Technical and Molecular Chemistry University of Hamburg Hamburg Germany I. INTRODUCTION Aromatic polyethers are a group of high-performance engineering plastics which were developed by several chemical companies over the past forty years. Poly phenylene ether s mostly prepared by oxydative polycondensation of phenols were the first class of aromatic polyethers which was technically produced and commercialized 1-3 . Perfectly linear poly arylene ether s free of side chains can only be obtained by oxidative coupling of 2 6-disubstituted phenols. Therefore the poly 2 6-dimethylphenylene-oxide usually called PPO is the most widely used poly arylene ether . Its outstanding property is its compatibility with polystyrene and a few other polymers so that it is mainly used as component of blends 4 . The oxidative coupling of phenols has intensively been studied between 1950 and 1980 as discussed in the 1st edition of this handbook but only few research activities were observed during the past 10 years discussed in the subchapter Various Aromatic Polyethers . Therefore the literature evaluated and discussed below mainly concerns poly ether sulfone s and poly ether ketone s. Furthermore semiaromatic polyethers and aromatic polysulfides are included in this chapter which mainly covers the literature of the years 1990 through spring 2000 complementary to the first edition . The characteristic properties and advantages of aromatic polyethers when compared to aliphatic engineering plastics based on an aliphatic main chain are as follows. Aromatic polyethers are less sensitive to oxydation at all temperatures and thus also less inflammable poly vinyl chloride and poly tetrafluoroethylene are of course exceptions in the case of aliphatic polymers . The thermostability of aromatic polyethers is higher. For all these reasons the maximum service temperature of aromatic polyethers 200260 C is twice as high as that of aliphatic .
