硬段含量对合成革用无溶剂聚氨酯性能的影响

Influence of hard-segments content on properties of solvent-free polyurethane used in synthetic leather

以聚四氢呋喃醚二醇-2000（PTMEG-2000）和异氟尔酮二异氰酸酯（IPDI）反应．得到异氰酸酯基（-NC0）含量为20％的无溶剂NCO封端聚氨酯预聚体，作为B组分；由1，4-丁二醇（1，4-BDO）、聚合物多元醇-2000和催化剂混合得到含羟基（-OH）的A组分；在R值（混合物料中-NCO与-OH的摩尔比）为1．1的条件下，调节1，4-BDO、聚合物多元醇-2000的用量，制备了不同硬段含量的无溶剂聚氨酯涂层，并研究了硬段含量对无溶剂聚氨酯性能的影响。结果表明：随着硬段含量的增加，无溶剂聚氨酯膜的100％模量和300％模量提高，拉伸强度增加，耐水性和耐水解性增强，断裂伸长率降低，透水汽性变差；X射线衍射（XRD）及热重分析（TGA）测定表明：硬段含量较高的无溶剂聚氨酯涂层具有较高的结晶度和更好的热稳定性。

Polytetramethylene ether glycol-2000 （PTMEG-2000） and isophorone diisocyanate （IPDI） were used to synthesize solvent-free polyurethane prepolymer whose isocyanate content was 20%, and referred to as component B. And then component A was prepared with hydroxyl groups （-OH） by mixing 1,4-butanediol （ 1,4-BDO）, pol- ymer polyol-2000 and the catalyst. Component A and B were mixed to prepare a series of solvent-free polyurethanes with different hard segment contents, hard segment content was regulated through the dosages of 1,4-BDO and poly- mer polyol-2000, while R was 1.1, and R was defined as molar ratio of --NCO and --OH. The effect of hard seg- ment contents on the properties of solvent-free PU samples was studied. Results show that with the increasing of the hard segment content, 100% modulus, 300% modulus, tensile strength of the prepared solvent-free polyurethane also increase. And the water resistance, hydrolytic resistance enhance as well, while the elongation at break and the water raper permeability decrease. X-ray diffraction （XRD） curves of PU samples show that PU sample with higher hard segment contents has higher erystallinity. Thermogravimetric analysis （TGA） tests show that PU sample with higher hard segment contents has better thermostability.