PBS/Chitosan and Polyolefin Nanocomposites: Synthesis, Properties and Biodegradation

Abstract

The current study focuses on the synthesis of biodegradable polymer nanocomposites as alternative to conventional composite systems. In this study, biodegradable nanocomposites of chitosan and PBS blend were generated (type 1 composites) utilizing graphene, silica and silicate as fillers. Nanocomposites of non-biodegradable PE and PP were also produced using the same fillers along with a functional additive, which enables the polymers to degrade (type 2 composites). Suitable weight ratio of poly(butylene succinate) (PBS) and chitosan (Cs) to prepare nanocomposites was identified based on the ease of processing, better mixing ability of the fillers with the matrix materials and the mechanical properties of the composites. The nanocomposites were characterized for their thermal, rheological, mechanical and morphological properties. It was observed that graphene incorporation provided the best improvement in Young's modulus and storage modulus in all cases. Thermal degradation resistance of the graphene nanocomposites was also the highest. Storage modulus, loss modulus and viscosity of nano-composites enhanced as a function of filler content. XRD analysis indicated that chitosan was well mixed with PBS and slight changes in crystallinity for both PE and PP nanocomposites were observed on incorporation of filler. The chitosan-PBS nanocomposites were observed to biodegrade as a function of time during the soil burial test. Bio-degradation was, in general, slowed down by the presence of fillers. MINITAB 16 software could be utilized to model and predict the elastic modulus of PBS-Cs nanocomposites based on DMA and shear rheology data. The preliminary degradation studies of PE and PE nanocomposites with 2.5% additive exhibited varying degrees of degradation in all the samples.

Date of Award	May 2013
Original language	American English
Supervisor	Vikas Mittal (Supervisor)