Morphology Of Linear Low-density Polyethylene Research Articles

Tearing properties, crystallization behavior, microstructure, and morphology of LLDPE with different short branched chain distributions

Abstract The length and distribution of comonomers with short-chain branching (SCB) have a significant influence on the crystallization behavior and crystal structure of polymers, as well as the mechanical properties of the material. This study investigates the crystallization behavior and properties of linear low-density polyethylene (LLDPE) samples with similar density, molecular weight, and branching degree but varying SCB distributions. The results show that LLDPE with butene as the comonomer has a stronger ability to suppress crystallization compared to LLDPE with hexene as the comonomer due to its more uniform SCB distribution. Additionally, among LLDPEs with comonomers of octene, hexene, and butene, the LLDPE with the most uniform SCB distribution exhibits the weakest crystallization ability. Small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) results indicate that LLDPE with more uniform distribution of SCB has smaller long-period and more regular lamellar structure. Therefore, LLDPE with more uniform SCB distribution exhibits weaker inhibition ability towards crystallization, leading to less agglomerated phases and weaker phase separation, resulting in higher tear strength.

Date Seeds Fiber Reinforced Low-Density Polyethylene: Effect of Stearic Acid on its Mechanical and Morphological Characteristics

The effect of different content of steric acid (3, 6 and 9 wt.%) on the mechanical properies (tensile, flexural and impact properties) and morphology of linear low-density polyethylene / date seeds (LLDPE/DS) composites were evaulated in this research. The composites were produced by using extrusion followed by injuction molding process. Results presented that the addition of steric acid at 3 wt.% to the composite has shown highest tensile strength and elongation at break as compared to other treated samples. This is due to the improvement on the fiber surface in presence of SA. However, the tensile strength and elongation at break decreased thereafter treatment with 6% and 9% of SA. Furthermore, the flexural and impact properties have shown the same trend of the tensile properties, this was consistent with the results shown on SEM micrographs.