聚氨酯在磨粒侵蚀条件下的表面化学效应

Surfacial Chemical Effects of Polyurethane Abrasive Erosion

在工程实际中，由于高分子材料的抗磨粒侵蚀性能都比较好而得到了广泛的应用。然而载至目前，所见这类材料在磨粒侵蚀磨损机理方面的研究报道还相当之少，而且仅局限于物理过程的考察。因此，对聚氨酯在磨粒侵蚀条件下的表面化学效应进行了试验研究。利用扫描电子显微镜、Ｘ射线光电子能谱仪和傅立叶表面红外分析仪，对这种高分子材料在磨粒侵蚀磨损前后表面的微观形貌、元素组成、结合能和官能团进行了分析。结果发现，聚氨酯在磨粒侵蚀条件下发生的表面化学效应主要有：聚氨酯分子中硬链段与软链段交界处的链断裂、脲基甲酸酯基团和缩二脲基团的热分解导致的热降解，以及氨基甲酸酯基团的水解。从化学角度考察聚氨酯的磨粒侵蚀磨损过程是在研究思路和方法上的一种新的尝试，其研究结果有助于深入而全面地认识高分子材料的磨损机理，因而对提高这类材料的使用寿命具有实用价值。

Polymeric materials with much better resistance to abrasive wear have been widelyused in engineering.However,the mechanisms of abrasive erosion for the materials remaininadequately investigated and are confined to study in physical process of wear up to now.Therefore, the surfacial chemical effects of abrasive erosion of polyurethane have beeninvestigated. Analyzing the surfaces of polyurethane before and after abrasive eroding for thesurface profile,element constitutions,binding energies,functional groupe have been made by usingscanning electron nucroscopy(SEM), X-ray photoelectron spectriscopy(XPS)and fourieytransform infrared spectrometer(FT-IR).It has been found that the surfacial chemical effects ofabrasive erosion of polyurethane examined could be summarized mainly as follows:(1) Fracture atthe conjunctions of hard parts and soft parts of the macromolecular chains of polyurethane;(2)Thermal decompeition of ureido- formic- ester and biuret;(3)Hydrulysis of cabamate。Investigating the wear process of abrasive erosion of polyurethane as viewed from chemical effects isa new attemp at research thinking and method,the results of which is a great help to achieve a deepand all-sided understanding of the wear mechanism of polymers. These results are much practicalvaluable to rade the working life of polymers。