丙烯酸树脂改性水性聚氨酯的结构与性能研究

采用丙烯酸树脂对水性聚氨酯进行改性，得到了共混改性（PU／PA）、共聚改性（PUA’）、接枝改性（PUA）3种丙烯酸改性水性聚氨酯聚合物。通过对改性聚氨酯乳液的激光粒度分析，乳胶膜的红外光谱、热分析、透明性、耐化学性及扫描电镜进行分析，结果表明：改性后的水性聚氨酯，各项性能均有不同程度的提高。在机械共混聚合物PU／PA体系中，聚氨酯分子链和丙烯酸树脂分子链间具有一定的相容性及共混性；在共聚反应聚合物PUA’、PUA体系中，聚氨酯分子链和丙烯酸树脂分子链形成核壳结构，且在PUA中，聚氨酯分子链和丙烯酸树脂分子链之间形成的化学键，可以有效的提高二者的相容性及共混程度。

Research on Structure and Characterization of Water- borne Polymerurethane Modified with Acrylic Resin

A series of water-borne polyurethane modified with acrylic resin were prepared by mechanical and chemical methods.Some characters of these polymers were reported in this paper.The transparency of films was tested with eyes,meanwhile the water and solvent resistibility of the film were assessed by conventional way.The particle size and distribution were tested with particle size analyzer,while the hydrogen bond behaviors of polyurethane were measured with IR spectra and the thermal behaviors of polymer films were analyzed with difference scan calories analyzer(DSC).The morphology of films were observed with scan electronically microscope(SEM).The results showed that,by mechanical method,the compatibility and commixing degree between polyurethane(PU) molecular chain and acrylic polymer(PA) molecular chain was limited.By chemical blend,PUA and PUA were gotten by emulsion polymerization and graft co-polymerization apparently.Both PUA and PUA were all core-shell polymerization.There were chemical bonds between PU and PA molecular chain,and the compatibility and commixing degree between PU molecular chain and PA molecular chain in PUA dispersion can be developed apparently.Accordingly,the overall performances of modified PU were developed.