【作者】 罗朝霞；

【导师】 李晓林；

【作者基本信息】 北京化工大学 ， 材料学， 2007， 硕士

【摘要】 酚醛泡沫是一种新型的绝热保温材料，它具有耐热、耐酸腐蚀、阻燃性优异、低烟无毒的特性，但是存在性脆、易掉渣的缺点。本文针对酚醛树脂泡沫增韧这一问题，通过对树脂的合成研究、工艺控制，以及发泡配方和工艺的探讨，初步得到了一种较好的树脂合成工艺条件和韧性增强的酚醛泡沫塑料。本文对高性能热固性酚醛树脂的合成条件进行了研究与探讨，首先研究了在F／P摩尔比1.6下，在不同的催化剂体系中，反应温度、反应时间对树脂分子量、分子量分布、分子结构的影响，同时考察了反应温度、反应时间对树脂反应活性、凝胶速度、粘度和固含量的影响，最终确定了适合树脂发泡的最佳合成催化剂体系，同时确定了合成反应的较为合适的工艺条件(反应温度和反应时间)。结果表明：双催化剂体系比单催化剂体系的树脂活性高、分子结构规整且性能要好，合成反应温度在95℃左右，反应时间在90-120min左右，得到的树脂分子量合适、分子量分布较窄。其次，考察了双催化剂体系下，不同分子量分布的树脂的分子结构、力学性能、耐热性能。结果表明：分子量分布和分子结构不同的树脂的力学性能各异。当数均分子量Mn＞430，分子量分布中酚醛树脂大于三、四聚体的分子量级分占多数时，树脂的强度都比较高。尤其是三、四聚体到二十聚体占有量比例最高，并且超高分子量级份极少时，树脂强度达到最高值2.05MPa。分子量分布不同的酚醛树脂，其热分解性能差异不大。再次，对树脂进行改性，考察了加入三聚氰胺、腰果壳油双改性后的树脂的分子结构和分子量，确定了合适的工艺条件。结果表明：加入三聚氰胺、腰果壳油双改性后，树脂的分子结构和分子量显著变化，分子量增加很快。最后，考察了树脂发泡情况，对影响树酚醛泡沫性能的因素进行了研究与探讨，同时比较了未改性树脂和改性树脂的发泡表面形貌及脆性(掉渣率)。结果表明改性后树脂泡沫的掉渣性明显减少，泡沫韧性增强。更多还原

【Abstract】 Phenolic foam is one kind of heat insulating material due to its high resist heat temperature,good inflaming retarding property,fewer smog and innocuous. Now the problem influencing of the phenolic foam is the brittleness. In this paper , in order to solve the brittleness,the synthesize and technics of phenolic resin were studied .And also ,the preparetion methodology and technics of phenolic foam were studied .By this way ,we obtained a better synthetical technics condition and a better toughed phenolic foam.In this paper, firstly we studied the influence of the reaction time and temperature to the molecular weight and molecular-weight distribution and structure of phenolic resins in different catalyst system at the mole ratio of F/P 1.6 , while we studied the influence of the reaction time and temperature to the reaction activity、gel time、viscosity and solid content of phenolic resins. The result showed that in double catalyst system the reaction activity and structure of resin are better than in single catalyst system. The molecular weight and molecular-weight distribution of phenolic resins are better at the reaction temperature 95℃and reaction time about 90-120min.Secondly, the structure、mechnics and heat-resistant property of phenolic resins with different molecular-weight distribution were studied in double catalyst system. The result showed that mechnics property of phenolic resins with different molecular-weight distribution were different.when the molecular-weight was more than 430 and three or four polymer were more in the molecular-weight distribution of phenolic resins, the intensity of resin was high. The heat resistent property of different molecular-weight distribution phenolic resins were resemble.Thirdly, the molecular weight and molecular-weight distribution and structure of phenolic resins modified by melamine and CNSL were studied . The result showed that after added CNSL and melamine, the molecular-weight of PF resins increased and the molecular-weight distribution and structure of PF resins remarkably changed.Finally, factors effecting on properties of phenolic foam were studied in this work. We also compared the apparent quality and brittleness of unmodifed and modified phenolic foam. The result showed that the brittleness of modified phenolic foam is obviously decreased. The toughness of modified phenolic foam is increased.更多还原