超高分子量聚乙烯加工中的亚稳性现象研究  

STUDY ON METASTABILITY PHENOMENON IN PROCESSING OF ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE

作　　者：吴丹[1] 方立明[1,2,3] 曹贤武 赵耀明[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640 [2]华南理工大学广东省高性能与功能高分子材料重点实验室,广州510640 [3]华南理工大学聚合物加工工程教育部重点实验室,广州510640

出　　处：《工程塑料应用》2009年第2期32-36,共5页Engineering Plastics Application

基　　金：国家自然科学基金资助项目(50803019);广东省自然科学基金资助项目(8451064101000727)

摘　　要：采用高压毛细管流变仪加工超高分子量聚乙烯（UHMWPE），研究发现加工温度在约高于理论结晶熔融点10℃附近的狭窄温度范围内，UHMWPE熔体流动出现亚稳性现象，即挤出压力突降，熔体粘度出现极小值，且流动稳定，加工的样品光滑，熔体破裂现象明显减弱。初步探讨了利用此种亚稳性现象加工UHMWPE的工艺条件，研究了不同温度下柱塞速率及载荷对产生亚稳性现象的影响。结果表明，对于粘均分子量为3．5×10^6的UHMWPE，加工温度在154～157℃可观察到亚稳性现象；利用该现象，采用高压毛细管流变仪加工UHMWPE可为解决其加工困难的问题提供一种新颖可行的方法。A high-pressure capillary rheometer was used to process ultrahigh molecular weight polyethylene （UHMWPE）. The metastability phenomenon of UHMWPE melt flow was observed in a narrow temperature window around 10% above the theoretical melting point of PE crystal. In this temperature window, the minimum values of extrusion pressure and melt viscosity were revealed, and the flow was stable. The surface of processed UHMWPE rod was smooth, and the melt fracture was significantly reduced. The feasibility of using metastability phenomenon to process UHMWPE was explored, and the effects of extrusion temperature, heat history, extrusion speed and applied load on the metastability phenomenon were studied. The results showed that the metastability phenomenon appeared in the temperature window of 154 - 157% for UHMWPE with a molecular weight of 3.5 × 10^6. This research could provide a new and practicable processing method to manufacture UHMWPE using a high-pressure capillary rheometer in a narrow low temperature window, which could improve the processability of UHMWPE.

关 键 词：超高分子量聚乙烯 亚稳性现象 挤出加工 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业] TQ325.3