Effect of Crosslinker and Micro/Nano Crystalline Cellulose on the Biodegradation of Starch/Polyvinyl Alcohol Films

Four sets of starch/polyvinyl alcohol (PVA) blend films reinforced with 10 weight% of micro/nano crystalline cellulose (MCC) particles were crosslinked with four different crosslinkers like epichlorohydrin (E), zinc oxide (Z), formaldehyde (F) and borax (B). They were then subjected to biodegradation studies for 30 days under controlled composting environment. Initially the crosslinkers and the filler exhibited a negative effect on the biodegradation in comparison to control (without any crosslinker and filler). In the later stage, breakdown of the crosslinks and the presence of MCC accelerated the rate of degradation. DSC (Differential scanning calorimetry) thermograms strongly suggested that initially a fraction of starch was consumed by the microorganisms and the remaining part of the starch and the PVA fraction were reorganized. Rough and undulated surfaces of biodegraded samples were observed under Scanning Electron Microscope (SEM) and the morphology was significantly different in each case. Thermogravimetric analysis (TGA) of the biodegraded samples clearly indicated molecular rearrangement which made the samples more resistant to thermal degradation.