Study and characterisation of the post processing ageing of sago pith waste biocomposites

• Main Authors: Lai, Jau Choy, Wan Aizan Wan Abdul Rahman,, Avérous, Luc, Lim, Teck Hock
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia 2016
• Online Access: http://journalarticle.ukm.my/9755/1/18_Jau_Choy_Lai.pdf; http://journalarticle.ukm.my/9755/; http://www.ukm.my/jsm/malay_journals/jilid45bil4_2016/KandunganJilid45Bil4_2016.htm

This paper reports the post-processing ageing phenomena of thermoplastic sago starch (TPS) and plasticised sago pith waste (SPW), which were processed using twin-screw extrusion and compression moulding techniques. Wide angle X-ray diffraction (XRD) analyses showed that after processing, starch molecules rearranged into VH-type (which was formed rapidly right post processing and concluded within 4 days) and B-type (which was formed slowly over a period of months) crystallites. Evidence from Fourier transform infrared spectroscopy (FTIR) analyses corroborated the 2-stage crystallisation process, which observed changes in peak styles and peak intensities (at 1043 and 1026 cm-1) and band-narrowing. Thermogravimetric analysis (TGA) studies showed that the thermal stability of plasticised SPW declined continuously for 90 days before gradual increments ensued. For all formulations tested, post-processing ageing led to drastic changes in the tensile strength (increased) and elongation at break (decreased). Glycerol and fibres restrained the retrogradation of starch molecules in TPS and SPW.