Effect of kapok husk content and chemical treatment on properties of linear low density polyethylene eco-composites

Abstract

The utilization of kapok husk (KH) as filler in linear low density polyethylene (LLDPE) was studied. The effect of KH content and chemical treatments on tensile properties, morphology, thermal properties and water absorption of LLDPE/KH eco-composites were investigated. The LLDPE/KH eco-composites were prepared by using Brabender Plasticorder EC-Plus at temperature 160 °C and rotor speed 50 rpm. The four types of chemical treatments used were methacrylic acid (MAA), citric acid (CA), lactic acid (LA) and sodium dodecyl sulfate (SDS). The results indicated that the addition of KH in LLDPE eco-composites had decreased the tensile strength, elongation at break and crystallinity of the eco-composites. However, the modulus of elasticity and water absorption of eco-composites increased with increasing of KH content. Presence of KH has lowered the thermal stability of LLDPE/KH eco-composites compare to neat LLDPE. However, the increment of KH content improved the thermal stability. The morphological studies of eco-composites exhibited poor interfacial interaction between KH filler and LLDPE matrix. The effect chemical treatment of KH had increased the tensile and thermal properties of eco-composites. The tensile strength and modulus of elasticity of treated LLDPE/KH eco-composites with MAA, CA, LA, and SDS were higher than untreated eco-composites. The crystallinity and thermal stability of treated LLDPE/KH eco-composites were also improved compared to untreated eco-composites. The treated eco-composites had better water resistance than untreated eco-composites. The better filler-matrix interaction has been proven by scanning electron microscope (SEM).Spectra FTIR analysis showed the changes of functional group of treated KH. From various chemical treatments, the treated eco-composites with MAA showed the highest tensile strength, modulus of elasticity, thermal stability, and degree of crystallinity compared to others treated eco-composites.