An investigation of the relationship between thermal relaxations and the impact performance of rotationally moulded linear low density polyethylenes

L. T. Pick, E. Harkin-Jones

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The objective of this paper is to provide a better understanding of how thermal relaxations in linear low density polyethylenes are related to the crack initiation energy of rotomoulded parts. Trials were carried out on two Ziegler-Natta catalysed linear low density polyethylenes (LLDPE) and two metallocene catalysed linear low-density polyethylenes (mLLDPE). Instrumented impact tests and dynamic mechanical thermal analysis (DMTA) were carried out on each material at a wide range of temperatures. The frequency of impact at each test temperature was determined, and the DMTA results were shifted to a corresponding frequency. A correlation can be seen between changes in loss modulus and crack initiation energy with temperature. When comparing the crack initiation energy of the samples and the tan δ values, it can be seen that the β transition affects the way in which the polymer behaves under impact. A method for predicting impact performance over a wide temperature range is proposed.

LanguageEnglish
Pages1-10
Number of pages10
JournalProceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
Volume219
Issue number1
DOIs
Publication statusPublished - 1 Feb 2005

Fingerprint

Linear low density polyethylenes
Crack initiation
Thermoanalysis
Temperature
Polymers
Hot Temperature

Keywords

  • Crack initiation
  • Impact strength
  • Polyethylene
  • Rotational moulding
  • Thermal transitions

Cite this

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