Effect of heat treatment on the ndcrophase separation of a segmented poly(urethane urea) (SPUU) copolymer based on poly (propylene oalde) diol

3

5 dithyltoluene diandne and 4

4' -diphenylmethane diisocyanate has been studied bymeans of fourier transform infrared spectroscopy. From room temperature up to 310 t

the hydrogen bonds between urethane linkages were dissociated gradually andthe hydrogen bonds between urea linkages with the bifuracted structure were formedrapidly between 130 - 200 ℃. A part of free urethane linkages formed hydrogen bonds again when the copolymer was annealed from 310℃ down to room temperature

meanwhile urea hydrogen bonds between hard segments formed continually.The result suggests that the extent of microphase sepearation of the SPUU copolymer can be increased efficiently with the help of heat treament between 130～200℃.