Investigate the effect of short chain branching and lamellar thickness on mechanical and optical properties of linear low-density polyethylene by successive self-nucleation/annealing (SSA) technique

In this article, various polyethylenes based on Ziegler-Natta and metallocene catalysts with different comonomer contents were investigated by successive self-nucleation and annealing (SSA) technique. Lamellar thickness, short chain branches content (SCBC) and methyl sequence lengths (MSL) were calculated by the modified Thomson-Gibbs equation and suitable calibration curves available in the literature. Moreover, linear low-density polyethylene (LLDPE) samples with different physical, mechanical and optical properties were investigated according to heat of fusion, the lamellar thickness, SCBC and methyl sequence length (MSL) of the multiple peaks. The results showed that the mechanical and optical properties such as dart drop impact strength, Elmendorf tear resistance, softening point and haze are associated with the lamellar thickness and SCBC of the resins.