超支化聚合物改性水性聚氨酯的制备与性能研究

Study on preparation and properties of waterborne polyurethane modified by hyperbranched polymer

以多官能度聚酯二元醇为软段、HBP(端羟基超支化聚酯)为改性交联剂、IPDI(异佛尔酮二异氰酸酯)和DMPA(二羟甲基丙酸)为硬段,采用原位聚合法制备出稳定的HBPU(超支化水性聚氨酯分散液),并对其结构和性能进行了分析。研究结果表明:经羟基比率为1∶6的HBP改性后,相应HBPU的表面张力降低,说明其对非极性基材的浸润性增强;由于WPU(水性聚氨酯)大分子链之间形成了交联网状结构,故HBPU胶膜的力学性能、硬度和热性能等得到明显改善。

With polyfunctional polyester diol as soft chain segment, HBP（hydroxyl-terminated hyperbranched polyester） as a modifier and cross linker,IPDI（isophorone diisocyanate） and DMPA（dihydroxymethyl propionicacid） as hard chain segments,the stable HBPU（hyperbranched waterborne polyurethane dispersion） was prepared by in situ polymerization method,and its structure and properties were analysed. The research results showed that the HBPU＇s wettability on non-polar substrate was reinforced because the surface tension of corresponding HBPU was reduced when the HBPU was modified by HBP with hydroxyl ratio at 1：6. The mechanical properties,hardnesses and thermal properties were obviously improved because the crosslinking network structure between macromolecule chains of WPU（waterbome polyurethane） was formed.