Journal of Applied Polymer Science, Vol.101, No.4, 2472-2481, 2006
Fracture behaviors of metallocene-catalyzed polyethylene elastomer via silane crosslinking
Silane moisture-cured metallocene-catalyzed polyethylene (mPE) to form an elastomer has been prepared. Metallocene polyethylenes with two different levels of comonomer contents were grafted with various amounts of vinyltriethoxy silane. "Threshold" fracture energy is roughly proportional to the reciprocal square root of Young's modulus. By relating tensile strength to tear strength, the corrected average depth of flaw is in the range of 40.5 +/- 11.0 mu m, which successfully confirms the extension of conventional elastomeric theory to the low crystalline vulcanizates under some limitations. The cutting strength of mPE vulcanizates gives an intermediate value when compared with crystalline plastics and conventional elastomer, and is comparable with other evaluations of cutting strength for different types of materials, which further signifies the importance of crystalline yielding even in the nano-fracture zone of deformation. (c) 2006 Wiley Periodicals, Inc.
Keywords:metallocene polyethylene (mPE);silane crosslinking;fracture behaviors;depth of flaw (natural flaw size)