Influence of several chemical treatment on the interfacial shear strength of zalacca fibres and low-density polyethylene matrix

The aim of this research is to study the influence of sodium hydroxide, sodium bicarbonate and calcium hydroxide treatment on the interfacial shear strength of zalacca fiber and low-density polyethylene matrix. The investigation was done by pull-out testing. The fiber was implanted in the LDPE matrix with the definite depth using hot press methods. The pulling was performed between one end of the fiber and the matrix in which the fiber was implanted. The pull-out test was followed by the morphological examination of fiber surface using SEM. The result indicated that the NaOH treatment increased the IFSS of ZF and LDPE matrix, followed by NaHCO₃ and Ca(OH)₂ treatment. The increase of IFSS reached 37.38, 8.33 and 2.63 % for NaOH, NaHCO₃ and Ca(OH)₂ treatment. This is due to the surface roughness of ZF caused by the chemical treatment. The NaOH treatment generates the roughest surface of ZF due to the partial elimination of hemicellulose and lignin, followed by NaHCO₃. The Ca(OH)₂ has the lowest delignification effect and slightly lower the hemicellulose and cellulose content so that it causes the minimum effect on the IFSS value.