摘要
采用聚乙二醇400与TDI合成了—NCO∶—OH不同摩尔比的低粘度PU预聚体,研究了预聚体的异氰酸值、粘度、储存期的变化;并将不同的预聚体以不同质量比分别加入到端羟基UPR中,研究UPR性能的变化并对其进行红外表征和SEM形貌分析。结果表明,减小—NCO∶—OH摩尔比,有利于合成分子量大、储存期长的PU预聚体;PU预聚体加入到UPR中时,异氰酸酯基和端羟基UPR发生扩链反应,当PU预聚体质量分数为15%时冲击强度提高了15%,质量分数为10%时,热变形温度提高6℃,有效地提高了UPR的冲击性能和热变形温度;当PU预聚体中—NCO∶—OH摩尔比减小时,有利于进一步提高UPR的冲击性能和热变形温度,使冲击断面呈现韧性断裂。
Low viscosity PU prepolymer of different Molar ratio —NCO∶—OH with PEG400 and TDI are synthesized in this article.Their isocyanate value,viscosity and storage period are researched,and then different prepolymers are added into UPR by different weight proportions.the properties transformations of UPR are researched and characterized with infrared spectrometric analyzer and SEM.The results indicate that reducing —NCO∶—OH Molar ratio is beneficial to obtain high molecular weight,long storage period PU perpolymer. Chain Extension exists between isocyanate groups and hydroxyl groups when adding PU perpolymer into UPR. When the wt= 15% of PU perpolymer, the impact property increases by 15%, when the wt = 10% of PU perpolymer, heat distortion temperature increases by 6℃ ,by this means the impact property and heat distortion temperature of UPR is increased effectively. At this time, reducing --N（X）：--OH Molar ratio is favorable to increase more impact property and heat distortion temperature, then the ductile fracture can be observed in SEM photographs.
出处
《武汉理工大学学报》
CAS
CSCD
北大核心
2009年第21期5-8,共4页
Journal of Wuhan University of Technology
关键词
聚氨酯预聚体
低粘度
冲击
热变形温度
polyurethane prepolymer
low viscosity
impact
heat distortion temperature
