Structural and free‐hole volume characterization of high‐density polyethylene‐chitosan composites plasticized with palm oil

Abstract

A series of high‐density polyethylene (HDPE) – chitosan (CS) composites with varying concentrations of chitosan have been prepared using a peroxide‐initiated melt mixing process with maleic anhydride as compatibilizer. Palm oil has been added as a plasticizer to the optimized HDPE/CS5 composite. The variation in the free hole volume, microstructure, and crystallinity of the prepared composites has been studied using Positron annihilation lifetime spectroscopy (PALS), dynamic mechanical analysis (DMA), and X‐ray diffractometry (XRD) respectively. The interaction between HDPE and chitosan is evidenced from the FTIR spectroscopic studies. The addition of palm oil to optimized HDPE‐CS composite increased the crystallinity upto 41.3%. A shift as well as a decrease in loss modulus was obtained for 5 wt% chitosan added HDPE sample which can be ascribed to the better crosslinking observed in the composite. The increased amorphization of HDPE‐chitosan composites with a higher concentration of chitosan beyond the optimized concentration is observed from the tan delta values. Free‐hole value is reduced by 20 Å3 with the addition of 5 wt% palm oil to HDPE/CS5 composite system. The microstructural analysis shows evidence of efficient interaction of HDPE‐chitosan system that can be used for further applications in medical field and food packaging industry.

Plastic Deformation of Polypropylene Studied by Positron Annihilation Lifetime Spectroscopy

“…In last 30 years, studies on polymeric systems were significantly intensified, and knowledge of the annihilation processes in these materials has advanced. Neat amorphous − and semicrystalline ,, polymers, as well as polymer-based blends , and micro-/nanocomposites, − were analyzed with the use of the PALS technique. Relationships between the initial structure of polymeric materials and transport, thermal or thermomechanical properties were typically investigated.…”

Design, fabrication, and characterization of natural fillers loaded HDPE composites for domestic applications

“…As reported in the literatures, the plain HDPE had clear reflection peaks at 21.3 , 23.8 , and 36.2 , which matched to the normal orthorhombic unit cell structures for the respective reflection planes of (1 1 0), (2 0 0), and (0 2 0). [61,62] The three crystalline peaks (1 1 0), (2 0 0), and (0 2 0) were not present in the CC loaded HDPE composite, hence these CC fillers influenced the crystal structure of the neat HDPE substrate.…”