二元醇为核单体的超支化聚酯的合成与性能

摘要

分别以乙基丁基丙二醇(BEPD)、1,4-丁二醇(BDO)和新戊二醇(NPG)为核单体，二羟甲基丙酸为AB2型单体，对甲苯磺酸为催化剂，采用准一步法合成了第三代超支化聚酯(HBP-1、HBP-2和HBP-3)。采用FT-IR、1H-NMR和GPC对其结构和分子量进行表征并测定了超支化聚酯的特性黏度。以甲苯二异氰酸酯加成物为固化剂，研究了超支化聚酯的固化涂膜性能，使用热重分析仪(TGA)考察了超支化聚酯涂膜的热稳定性能。结果表明，三种核单体成功合成了超支化聚酯，以BEPD为核单体的超支化聚酯HBP-1具有最高的支化度达到0.55。GPC测得的分子量与理论分子量接近，且以BEPD为核的HBP-1分子量分布最低为1.68。超支化聚酯在极性溶剂中有较好的溶解性能，在非极性溶剂中不溶，其中HBP-1具有更好的溶解性能和较低的特性黏度(4.24 mL⋅g−1)。超支化聚酯的固化涂膜具有较好的热稳定性、优异的附着力、柔韧性和较高的硬度。%　　The third generation hyperbranched polyesters (HBPs) were synthesized by the pseudo-one step method with 2,2-bis(hydroxyl-methyl) propionic acid as AB2 monomer, p-toluene sulfonic acid as catalyst, in which 2-butyl-2-ethyl-1,3-propanediol (BEPD, HBP-1), 1,4-butanediol (BDO, HBP-2), and neopentyl glycol (NPG, HBP-3) were used as the core monomers, respectively. The structures and molecular weights of HBPs were characterized with FT-IR, NMR and GPC as well as their intrinsic viscosities were also given. The film properties of HBPs cured by the toluene diisocyanate adduct were tested. The thermal stability of cured HBPs films were also examined by thermogravimetric analysis (TGA). It was found that HBPs are successfully synthesized and HBP-1 displays the highest branching degree up to 0.55. The GPC measured molecular weights of HBPs approach to the theoretical values, and HBP-1 exhibits the lowest polydispersity index up to 1.68. HBPs are soluble in strong polar solvents and insoluble in non-polar solvents and HBP-1 displays better solubility and lower intrinsic viscosity up to 4.24 mL⋅g−1. The cured HBPs films exhibit good thermal stability, adhesion, flexibility, and high hardness.