Characterization of Hydrolytic Degradation of Polylactic acid/Rice Hulls Composites in Water at Different Temperatures
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Date
2011
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Publisher
Express Polym Lett
Abstract
. Hydrolytic degradations of polylactic acid/rice hulls (PLA/RH) composites with various rice hulls contents due
to water absorptions at 23, 51 and 69°C were investigated by studying the thermal properties, chemical composition,
molecular weight, and morphology of the degraded products. The results have attested that the stability of PLA/RH composites
in water depends slightly on rice hulls contents but it is significantly influenced by water temperature. Water absorption
in 30 days at 23°C was between 0.87 and 9.25% depending on rice hull contents. However, at thermophilic
temperatures, the water absorption and degradation of these products were increased significantly. Saturations were
achieved in less than 25 and 9 days at 51°C and 69°C, respectively, while hydrolytic degradation was demonstrated by an
increase in fragility and development of crystallinity. At 69°C, there were significant reductions of the decomposition and
glass transition temperatures of the polymer by 13°C. These changes were associated with the reduction of the molecular
weight of PLA from 153.1 kDa to !10.7 kDa due to hydrolysis of its ester group.
Description
Keywords
biodegradable polymers, polylactic acid, rice hulls, hydrolytic degradation, molecular weight
Citation
Ndazi, B.S. and Karlsson, S., 2011. Characterization of hydrolytic degradation of polylactic acid/rice hulls composites in water at different temperatures. Express Polym Lett, 5, pp.119-131.