丙烯酸酯型端羟基聚醚双固化黏合剂的合成及打印成型固化机理

Synthesis and 3D printing curing mechanism of acrylate hydroxyl-terminated polyether dual-curing adhesive

以聚四氢呋喃醚二醇(PTHF)和3-甲基-3-丙烯酰氧甲基氧杂环丁烷(MMO)为原料,通过阳离子开环聚合反应机理,设计、合成了丙烯酸酯型端羟基聚醚黏合剂(MAPTHF),再与六亚甲基二异氰酸酯缩二脲固化剂(N-100)、2,4,6-三甲基苯甲酰基二苯基氧化膦(TPO)和1,4-丁二醇(BDO)组成光-热双固化黏合体系,通过光固化、热固化双步骤获得了光-热双固化弹性体。采用FTIR、NMR和GPC表征了MAPTHF的结构组成和物性参数,探究了光-热双固化黏合体系最佳的固化工艺参数和较优的物料配比,考察了光-热双固化弹性体的力学性能和热稳定性。结果表明,MAPTHF光-热双固化黏合体系可在紫外光照(5 W,395 nm)下5 s快速固化,在加热(65℃)3.0 h内实现完全固化,具有快速固化成形和短时间内完全固化特征;光-热双固化弹性体的拉伸强度为3.15 MPa,断裂伸长率为350%。该光-热双固化黏合体系用于3D打印复合推进剂,得到了较优异的打印成型效果。

Acrylate hydroxyl-terminated polyether adhesive(MAPTHF)was synthesized from cationic ring-opening polymerization of polytetrahydrofuran ether diol(PTHF)and oxacyclobutane methacrylate(MMO),then the photo-thermal dual-curing adhesive system was composed of hexamethylenediisocyanate diurea curing agent(N-100),2,4,6-trimethylbenzoyldiphenylphosphine oxide(TPO)and 1,4-butanediol(BDO),and went through photocuring and thermal curing to further obtain photo-thermal dual-curing adhesion-based elastomer.The MAPTHF was characterized by FTIR,NMR and GPC for structural composition and physical properties.The curing process parameters and the material ratio of the photo-thermal dual-curing system were optimized,with the photo-thermal dual-curing elastomer evaluated for its mechanical properties and thermal stability.The results showed that the target MAPTHF-based adhesive system could be cured quickly within 5 s under ultraviolet light(5 W,395 nm)and completely cured within 3.0 h under heating,exhibiting the characteristics of fast curing forming and complete curing in a short time.The tensile strength and elongation at break of photo-thermal dual-curing elastomer were 3.15 MPa and 350%,respectively.This photo-thermal dual-curing adhesive system was used for 3D printing of composite propellants,and excellent printing forming effect was obtained.