聚苯醚砜合成的动力学研究

Study on the Kinetics of Synthesis of Polyethersulphone

4-氯,4’-羟基二苯酚的溶液聚合(单酚法)和4,4’-二氯二苯砜(DDS)、4,4’-二羟基二苯砜(双酚S)的溶液缩聚(双酚法)是国内合成聚苯醚砜(PES)的两种主要合成路线。本文着重研究了单酚法和双酚法的动力学机理,比较后发现,双酚法缩聚符合二级反应机理,而单酚法则偏离二级反应。进一步研究发现,双酚-S的钠盐在这一亲核反应的缩聚中远比单酚的钠盐活泼,而且DDS和双酚-S钠盐的缩聚反应起动快,而单酚钠盐缩聚反应则起动缓慢但逐步加速。

It is known that 4-chloro, 4′-hydroxydiphenylsulphone(Ⅰ) solution polymerization (monohydric phenol method) and 4,4′-dihydroxydiphenylsulphone(Ⅱ), 4,4′-dichlorodiphenylsulphone(Ⅲ) solution copolycondensation (bisphenols method) are the two major methods for synthesizing polyethersulphone(PES) in China.In this paper, the kinetics of monohydric phenol method and bisphenol method are studied. After having compared the kinetics of the two copolycondensations, we come to the conclusion that the bisphenols method strictly conforms tp the mechanism of a second order copolycondensation, while the monohydric phenols method deviates from it.It is also found that sodium salts of monomer(Ⅱ) is much more reactive than that of monomer(Ⅰ) in the polycondensation which is a nucleophilic reaction. Besides, the copolycondensation between sodium salt of monomer (Ⅱ) and monomer (Ⅲ) starts faster at beginning and slows down to a constant reaction rate, while the copoycondensation of monomer (Ⅰ) starts slowly and accelerates gradually.