SMC中不饱和聚酯树脂增稠及贮存性能的研究

本文以甲苯二异氰酸酯（TDI）及其预聚物PU400、PU200为增稠剂对端羟基的不饱和聚酯进行增稠，通过树脂的粘度变化、螺线流动实验对这种新型增稠体系的增稠性能和片材的贮存稳定性进行了研究。并与以MgO为增稠剂的片材进行了对比研究，结果表明：（1）异氰酸酯预聚体的增稠性能优于异氰酸酯单体。（2）增稠剂PU400的质量百分数Wpu应该小于10％。在相同的－NCO浓度下，不饱和聚酯树脂的增稠速度随分子量的提高而加快；在273K下，不饱和聚酯树脂能在4天内完成增稠，在323K下，能在8小时内完成增稠。（3）聚酯片材贮存三个月后，由异氰酸酯增稠体系制备的片材的螺线长度，低于氧化镁增稠体系的下降幅度。

Study on Thickening Behavior and Storage Stability of Unsaturated Polyester in SMC

The hydroxy-terminated unsaturated polyester is thickened by 2,4-toluene diisocyanate (TDI) and diisocyanate compounds.By means of the analysis of viscosity changes and the spiral flowing,the thickening behavior and the storage stability have been investigated.The results show that:(1)The thickening property of preliminary diisocyanate polymer is beter than diisocyanate monomer.(2)The usage of PU 400 should be under 10%,otherwise the preliminary viscosity growth would be faster and the wetting of glass fabric will be difficult;When the -NCO concentration of diisocyanate compounds is the same,the thickening rate will be faster with the increase of its molecular weight;The unsaturated polyester can be thickened by PU 400 within four days at 273K,while within 8 hrs at 323K.(3)The spiral flowing length of sheet compound thickened by diisocyanate compounds decreases from 105mm to 86mm in three months.