1,3-丁二醇对PTMG/MDI体系聚氨酯弹性体力学性能的影响

以纯4,4′-二苯基甲烷二异氰酸酯（MDI）MDI-100、液化MDI（C-MDI）、MDI-50和四氢呋喃均聚醚（PTMG）为原料合成聚氨酯（PU）预聚体,再分别与KD和KC扩链剂制备PU弹性体。研究了1,3-BDO含量、异氰酸酯类型、预聚体NCO基含量、聚醚软段相对分子质量对PU弹性体力学性能的影响。结果表明,提高1,3-BDO含量可使PU弹性体的硬度、撕裂强度和冲击弹性明显下降;纯MDI弹性体综合力学性能最好,液化MDI次之,MDI-50最差;提高预聚体NCO基含量可使弹性体的硬度、300%定伸应力和撕裂强度明显提高,拉断伸长率和冲击弹性则下降;软段相对分子质量为1000时,PU弹性体的300%定伸应力、拉伸强度和撕裂强度均增加;软段相对分子质量为1800以上,拉断伸长率和冲击弹性增加。

Effect of 1,3-Butanediol on Mechanical Properties of Polyurethane Elastomers Based on PTMG/MDI

Polyurethane（PU） prepolymer was synthesized by using 4,4′-diphenylmethane diisoyanate（MDI-100）,liquidated-MDI（C-MDI）,MDI-50 and polytetramethylene glycol（PTMG） as raw materials.Polyurethane elastomers were prepared with KD and KC as chain extenders.The mechanical properties of the prepared PU elastomer were investigated.The results showed that the hardness,tear strength and impact elasticity decreased rapidly with the increase of mass fraction of 1,3-butanediol.The MDI / PU had the best mechanical property,C-MDI/PU lower,MDI-50/PU was lowest.The hardness,300% modulus and tear strength was enhanced rapidly with the increase of mass fraction of NCO in prepolymer,but elongation at break and impact elasticity was decreased.The 300% modulus,tensile strength and tear strength of PU were increased when Mn of soft segment was 1 000;the elongation and impact elasticity of PU were increased when molecular weight of soft segment was more than 1 800.