【作者】 刘义红；

【导师】 刘胜平；

【作者基本信息】 哈尔滨理工大学 ， 材料学， 2003， 硕士

【摘要】 本文将端羟基封端和端羧基封端的聚氨酯（PU）预聚物分别与酚醛树脂（PF）固化，制备了两种体系的增韧复合物。文中利用红外光谱对PF/PU共混物的分子结构进行了定性分析，利用扫描电镜对共混物冲击断面形貌进行了表征、用简支梁冲击试验机按国标测试PF/PU共混物的冲击强度，并按国标测试共混物体积收缩率，最后利用热重分析对PF/PU共混物的热稳定性进行测试。同时将两种PF/PU体系的共混物增韧各项性能进行对比，并对两种不同体系的增韧机理进行了讨论。研究结果表明：（1）增加促进剂用量，提高固化温度对共混物的凝胶速度有明显的促进作用，但凝胶速度过快会导致低分子物挥发不完全，影响固化效果，通过对比我们选择的固化条件为：促进剂用量3.5%，固化温度为80℃。（2）冲击实验结果表明二种PU预聚物均能提高PF的冲击强度，增韧效果与PU质量分数WPU有关；而端羧基PU能使复合物冲击强度达到的最大值比端羟基PU稍大。（3）随着聚氨酯预聚物加入量的增加，PF/PU共混物的体积收缩率明显变小，并能达到负值，但共混物仍具有良好的热稳定性。（4）通过红外光谱对PF/PU共混物分子结构进行的定性分析、以及扫描电镜对冲击断面形貌进行的分析，可证明聚氨酯预聚物增韧酚醛树脂的机理是：两个体系都是由于高分子量的线形氨基甲酸酯结构而增韧；端羟基PU与PF在共固化中产生化学键效应，参与PF的固化；而端羧基PU则与PF形成半互穿网络而增韧。更多还原

【Abstract】 The hydroxyl-terminated and carboxyl-terminated PU-prepolymer were prepared and cured respectively with PF. The molecule structures of two composite systems were characterized by means of FT-IR, and cured-sample morphologies were analyzed by SEM. By means of the measurement of properties of PF, impact strength, volume shrinkage and thermal stability of PF/PU composite, effect of PU on PF has been investigated and the toughening differentials have been compared , then two kinds of toughening mechanisms have been discussed. The results show that :(1) The cure is accelerated by increasing the usage of cure catalyst and cure temperature, but cure effect is bad with too fast speed, so 3.5% cure catalyst and 80℃ cure temperature were cheese. (2) The results of impact experiments show that impact strength of PF is improved and improvement lever is related to WPU; but effect of carboxyl-terminated PU-prepolymer is better, that is to say the interpenetrating networks have priority at toughening of thermosetting resin. (3) volume shrinkage of composite decreases greatly with WPU　increasing, even can arrive a negative number, but thermal stability is still good.(4)toughening mechanism is that :the formation of high molecular linear amino formate construct is the toughening reason; hydroxyl-terminated PU-prepolymer and PF react to produce chemical bond effect which participate cure; carboxyl-terminated PU-prepolymer and PF form semi-IPN which make toughened PF occur maximum.更多还原