摘要
采用六亚甲基四胺做催化剂,加入聚乙烯醇(PVA)、三聚氰胺和硫脲作为改性剂,通过降低甲醛与尿素物质的量比、采用尿素分批加入的合成方法,制备出改性低毒的脲醛树脂(UF),使游离甲醛质量分数低于0.30%;采用捏合和模压成型方法,将改性和普通UF树脂分别与剑麻纤维(SF)制备UF/SF共混复合材料,研究了复合材料的力学性能和吸水性能。结果表明,甲醛和尿素物质的量比为1.1时,游离甲醛质量分数降低到0.16%;甲醛和尿素物质的量比为1.2时,三聚氰胺、PVA及硫脲加入量分别为尿素总量的2.0%,1.5%,1.0%(质量分数)时,游离甲醛质量分数降低到了0.10%,粘度达到0.41 Pa·s,贮存期大于80 d;改性UF/SF复合材料的性能比普通UF/SF复合材料的冲击性能和耐磨性能分别提高了114%和261%。
Low toxic urea-formaldehyde （UF）resin which had low content of the free formaldehyde（≤0.30 %）was prepared by using the polyvinyl alcohol, melamine and thiourea as modification agents, hexamethylenetetramine as activator , depressed formaldehyde/urea ratio and adding urea by steps. By blending and molding methods the UF/SF composites were prepared, and mechanical properties and water absorption properties of the composites were studied. The results show that when the formaldehyde and urea molar ratio is 1.1, the content of the free formaldehyde is 0. 16% （mass fraction）. When formaldehyde and urea molar ratio is 1.2, the amount of polyvinyl alcohol, melamine and thiourea respectively is 2.0 %, 1.5 % and 1.0 % of the total amount of the urea, the content of the free formaldehyde is 0.10%（mass fraction）, viscosity of the improved UF/SF composite reaches 0.41 Pa· s, and the storage age of the improved UF/SF composite is longer than 80 d. The mechanical properties of improved UF/SF composites are better than common UF/SF composites, especially impact strength and wear resistance are enhanced by 114%and 261%.
出处
《现代塑料加工应用》
CAS
北大核心
2007年第5期16-19,共4页
Modern Plastics Processing and Applications
基金
广西科技厅资助项目(桂科能05112001-2A)
广西教育厅资助项目[桂教科研(2004)20]
关键词
脲醛树脂
改性
合成
性能
复合材料
urea- formaldehyde resin
modification
synthesis
property
composite
