水性聚氨酯改性天然胶乳膜的制备及性能

Preparation and Properties of Modified Natural Rubber Latex Film with Waterborne Polyurethane

采用机械法制备水性聚氨酯(WPU)/天然胶乳(NRL)的共混乳液,自然流延并在热空气中硫化制得WPU/NRL硫化胶膜,考察了不同WPU用量下共混乳液的加工性能、胶膜硫化特性和硫化胶膜的力学性能、透气性及耐溶剂性。结果表明:随着WPU用量的增加,共混乳液的黏度上升,表面张力变化较小。WPU/NRL胶膜的正硫化时间缩短,交联密度先增大后减小;硫化胶膜的断裂伸长率降低,拉伸强度和300%定伸应力先增大后减小,硬度增大,当WPU用量为7.5份时,硫化胶膜的拉伸强度达到27.84 MPa。与NRL硫化膜相比,WPU/NRL硫化胶膜的透气性有所降低,耐溶剂性能与致密性得到改善。

The blending emulsion of waterborne polyurethane （WPU） /natural rubber latex （NRL） was prepared by mechanical method, and it became WPU/NRL vulcanized film after natural casting in hot air vulcanization. The processing performance of blending emulsion, the vulcanized characteristics, gas permeability and solvent resistance of vulcanized films were investigated by different dosages of WPU. The results show that, with the increase of WPU addition, the viscosity of blending emulsion increases significantly, the surface tension changes a little, the film vulcanization time reduced, the cross-linking density increases first and decreases then, the elongation at break of vulcanized film decreases, the tensile strength and 300% modulus increase first and decrease then, and hardness increases. When the WPU amount is 7.5 parts, the tensile strength of the vulcanized film reaches the value of 27. 84 MPa. Compared to the NRL vulcanized film, the permeability of the WPU/NRL vulcanized film decreases, the solvent resistance and the compactness are improved.