摘要
研究了聚乙烯(PE)护套材料在拉伸应力、紫外光下的老化开裂行为。用光学显微镜观察老化试样被辐照表面并拍照,确定在各应力条件下试样的临界开裂时间,研究了老化裂纹的形态;应用红外分析手段,研究了应力水平对老化开裂的影响,并探讨了PE护套的应力、紫外老化开裂的机理。结果表明:当应力水平由材料拉伸强度的10%增长到30%时,材料的耐应力、紫外老化开裂性能则由原来的80%下降至20%;在无张应力作用时,试样裂纹是无规孔洞结构,而在有张应力作用时,裂纹则是有规律的垂直于应力方向的细长结构;应力作用改变材料取向度,产生应力集中使分子链被抽拔或者断裂,促进分子链的氧化断链,加速材料的老化开裂。
In this paper, the aging cracking behaviour of polyethylene （PE） jacket under the stress and UV irradiate was studied. In order to ensure the critical time of the ageing cracking, the surface of ageing sample by using the optical microscope was observed. Studying the effect of stress level on the ageing cracking, discussing the mechanism of ageing cracking under UV irradiate with FT-IR. The results indicated that the property of ageing cracking of PE decrease from 80% to 20% accompaning with the stress level rising from 10% to 30% of the tensile stress. Without stress the structural of crack was random cavern, but under stress, it was slenderness structure which was directly perpendicular to the stress in regularly. Stress changed the degree of orientation, the accumulated stress made the molecular chain break or pull out, stimulated the oxidized chain scission of molecular chain and accelerated the ageing cracking of the materials.
出处
《塑料工业》
CAS
CSCD
北大核心
2011年第11期83-86,共4页
China Plastics Industry
关键词
聚乙烯
护套
应力
老化
开裂
取向
Polyethylene
Jacket
Stress
Ageing
Crack
Orientation
