Effect of Chemical Treatment on Mechanical and Water-Sorption Properties Coconut Fiber-Unsaturated Polyester from Recycled PET

Abstract

Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. Morphological and mechanical properties of the composite have also been investigated to study the effect of fiber surface treatment. The influence of water uptake on the sorption characteristics of composites was studied via immersion in distilled water at room temperature. Surface treatment of coconut fiber caused a significant increase in the tensile properties with the optimum treatment of 0.5% silane on the 5% alkalized coconut fiber/polyester composites. For water absorption study, it was observed that the treated fiber composites showed lower water absorption properties in comparison to those of untreated fiber composites. SEM investigation showed that the surface modification of fiber has better fiber-matrix interaction. Thus, chemical treatments on the fiber improve fiber/matrix adhesion especially for silane on alkalized fiber treatment.

Properties and characterization of wood plastic composites made from agro-waste materials and post-used expanded polyester foam

“…As the hydroxyl groups are reduced, the water resistance of WPCs become higher, similar findings were reported by Thaker et al 25 A similar result was also found by Munirah and Ahmad. 34 They claimed that the chemical treatment on composites possessed higher water resistance than untreated composites. Table 3 summarizes the percentage of water absorption in untreated and treated EPS/CSP WPCs.…”

A review on the limitations of natural fibres and natural fibre composites with emphasis on tensile strength using coir as a case study

“…However, moisture absorption of natural fibres can be minimised by several processes such as coating [ 67 , 73 ], treatment with chemicals such as NaOH, acetylation, toluene diisocyanate, silane on alkali [ 64 , 74 – 77 ], use of coupling agents such as maleated anhydride grafted polypropylene (MAPP), maleic anhydride polyethylene (MAPE), silane [ 63 , 78 , 79 ]. A decrease in water absorption in coir fibres after surface treatments using NaOH, silane and alkalized silane was reported [ 73 ].…”

“…Coupling agents improve the adhesion between fibre and matrix, thus aiding in reacting with the hydroxyl group and decrease in the rate of the diffusion process and hence reduction in moisture ingress [ 68 , 73 , 79 ]. Coatings such as latex coatings act in a similar way as coupling agents by partially shielding the pores on the surface of the fibre, thus reducing the penetration of moisture into the fibre.…”

Surface Modification of PET Fiber with Hybrid Coating and Its Effect on the Properties of PP Composites

“…Currently, coating modification of the fiber surface is gradually becoming a hot research topic. The coating on the fiber surface can not only reduce the thermal stress between the fiber and the resin matrix during processing procedure and repair defects on the surface of fiber and damages caused by alkali treatment, but also improve the molecular structure of the fiber surface and improve the wettability of PET fiber in the resin matrix [9]. However, modification of PET fiber through surface coating has rarely been reported.…”