硫醇@三聚氰胺甲醛树脂/环氧树脂固化剂的制备及性能表征

采用三聚氰胺-甲醛树脂(PMF)为壁材,三羟甲基丙烷三(3-巯基丙酸酯)(TMPMP)作为芯材,原位乳液聚合法制备了硫醇@三聚氰胺甲醛树脂(TMPMP@PMF)微胶囊固化剂。研究了乳化剂种类及用量,囊壁质量比,反应温度,反应时间,pH值对合成TMPMP@PMF微胶囊粒径及稳定性等影响。结果表明:当反应乳液中芯材的质量分数达到2wt%,同时芯材与壁材的单体质量比达到2∶1时,能制备出粒径在大约100μm,粒径均匀的TMPMP@PMF微胶囊。TMPMP@PMF微胶囊的结构稳定,耐热性好,并且呈闭孔结构。采用TMPMP@PMF微胶囊为固化剂,与环氧树脂(EP)基体混合配制成压敏型TMPMP@PMF/EP固化剂,发现微胶囊结构在受到外力作用时能及时破裂,室温甚至低温下都能短时间使环氧树脂固化,并且能够很好地改善固化剂的抗冲击性能。

Synthesis and characterization of polythiol@melamine-formaldehyde resin for epoxy based hardener

With using poly-(melamine-formaldehyde ) (PMF ) as the shell and Trimethylolpropane tris (3-mercaptopropionate)(TMPMP)as the core,TMPMP@PMF for epoxy based hardner was synthesized by in situ polymerization process.The influences of the content and type of emulsifier,the mass ratio between the core and the shell,reaction time and temperature,pH value on the properties and structural of obtained micro-encapsultes were studied.The results show that an optimal synthesis condition can be obtained with the content of 2wt% TMPMP and the mixing mass ratio of 2∶1 between TMPMP to PMF.The obtained TMPMP@PMF encapsulates have stable morphology,closed shell structure and heat resistant performance.In addition the pressure-sensitive hardner of TMPMP@PMF/EP was prepared by mixing TMPMP@PMF and epoxy based hardener (EP).The results show that the microcapsules can be timely fractured under the action of external force,so EP also can be solidified in a short time at room temperature or even lower temperature (about 0 ℃),and the curing performance and the impact resistant performance of TMPMP@PMF/EP hardner can be effectively improved.