马来酸酐封端聚碳酸亚丙酯的大分子偶联反应

自从 1 969年井上祥平1] 发现二氧化碳 (CO2 )可以同环氧化合物直接共聚合成脂肪族聚碳酸酯(APC)以来 ,这一学科领域受到科学家的广泛关注2～ 8] .这是因为CO2 所产生的温室效应 ,成为使全球变暖的主要因素9,10 ] .已经确定CO2 使气侯变暖占诸多因素中的 66% .目前大气中CO2 的体积浓度为 345ppmv,由于人类的各类活动每年以 1ppmv的速度递增 .因此 ,降低CO2 排放量已成为全人类共同关注的热点之一 .另一方面 ,CO2 的固定化以及消耗、利用显然是一个应积极鼓励的研究课题 .目前人们已经将CO2 同环氧乙烷 (EO)、环氧丙烷 (PO)、环…

COUPLING REACTION OF POLY(PROPYLENE CARBONATE) END-CAPPED WITH MALEIC ANHYDRIDE

The effect of temperature on the characteristic of Fourier Transform Infrared(FTIR),the dependence of the average molecular weight and the polydispersity on the annealing temperature and the relationship between linear expansion coefficients and temperature of poly(propylene carbonate) end-capped with maleic anhydride(MA-PPC) were investigated.The vibration peak of hydroxyl group at 1714?cm -1 in the FTIR spectra,which belongs to the carboxyl end-group in MA-PPC,decreases with increasing the temperature of the sample and it disappeared totally when the sample was heated over 70℃.The average molecular weight of MA-PPC almost doubled when the sample was annealed at 110～150℃ for 30 min,however the polydispersity was maintained roughly.A new relaxation transition at about 80℃ was detected on the curve of the linear expansion coefficient versus temperature that is the characteristic of macromolecular coupling or crosslinking reaction.These results confirmed that the macromolecular coupling reaction was carried out between the end carboxyl groups of MA-PPC when the sample was heated over 70℃.