Soil Burial of Polyethylene-g-(Maleic Anhydride) Compatibilised LLDPE/Soya Powder Blends
(851 – 861)  Polymer - Plastics Technology and Engineering 50 #8 (2011)
Sam, Ismail and Ahmad of the Universiti Sains Malaysia, Malaysia compared the composting of linear low density polyethylene (LLDPE)/soya powder blends to be used as alternatives to cellulosic material/polyolefin blends.   LLDPE was blended with soya powder in a Haake internal mixer by melt mixing.   Composition of the soya powder was varied from 5 wt% to 40 wt%.  Polyethylene grafted maleic anhydride (PE-g-MA) was used as a compatibiliser.   Environmental degradation was evaluated by composting the blends sample into the soil. It was found that for a higher soya powder composition, the degradation rate increased.  Blends with compatibiliser degraded at lower rates than the uncompatibilised blends.  The carbonyl indices of uncompatibilised blends subjected to the soil burial test were found to be higher than compatibilised blends.   (RDC 6/9/2011)

Effect of Cobalt Stearate on Natural Weathering of LLDPE/Soya Powder Blends
(957 - 968) Polymer - Plastics Technology and Engineering 50 #9 (2011)
Sam, Ismail and Ahmad of Pulau Pinang, Malaysia, blended a protein-based natural polymer, soya powder, with linear-low density polyethylene (LLDPE). Cobalt stearate (CS) was used as a pro-oxidant.  The blends were exposed to natural weathering for 6 months. The susceptibility of the LLDPE/soya powder, based on its tensile properties, morphology, thermal behaviour and chemical and physical changes was measured every three months. The tensile strength and elongation at break (Eb) of the blends with CS were more susceptible compared to the blends without CS. During weathering, the crystallinity and weight loss increased with the addition of CS in the blends, however molecular weight was reduced.