A high-density polyethylene (HDPE) homopolymer was blended with a linear low-density polyethylene (LLDPE), i.e. an ethylene-hexene copolymer, over the composition range of 0-100%. The resistance to slow crack growth was measured by a notched tensile test under a constant load. The times to failure increased from about 102 min to 10 s min as the composition increased from 0 to 100% of the copolymer. In the range of compositions below 50% of the copolymer, the time to failure increased relatively slowly with composition compared to the very rapid rate of increase for compositions greater than 50% of the copolymer. The results were explained in terms of a network formed by the crystals and tie molecules that contained short-chain branches. The network becomes continuous when the copolymer is the major component and consequently the resistance to slow crack growth increases rapidly
Посилання на статтю:
The effect of blending high-density and linear low-density polyethylenes on slow crack growth / Zhiqiang Zhou, Xici Lu and Norman Brown // Polymer. – 1993. – Vol 34. – P. 2520-2523.