Investigation On Hydrophobic Properties Of Novel Thermoplastic Starch Biocornposites

The waterproof property of bacterial cellulose(BC) reinforcing novel thermoplastic starch biocomposites by adding citric acid(CA) and incorporation of Polylactic acid(PLA) and Polybutylene adipate-co-terethphlate(PBAT) was successfully prepared TPS100BC0.02CAx,(TPS100BC0.02CA0.1)xPBATy and (TPS100BC0.02CA0.1)xPLAy series specimens. The tensile strength and impact strength maximum value of TPS100BC0.02CAx series specimens reach23.5MPa and1KJ/m2when the CA content reached0.1phr. TPS, TPS,ooBCo.o2and TPS100BC0.02CAx series specimens tensile strength and impact strength were decreased with increased storage time.(TPS100BC0.02CA0.1)xPLAy and (TPS100BC0.02CA0.1)xPBATy series specimens initial tensile strength, elongation at break and impact strength were persistently increased with PLA and PBAT content≥20and60wt%.But their tensile strength were lower than TPS100BC0.02CA0.1sample with PLA and PBAT content=10and50wt%. TPS, TPS100BC0.02, TPS100BC0.02CA0.1,(TPS100BC0.02CA0.1)xPLAy and (TPS100BC0.02CA0.1)xPBATy series specimens tensile strength and impact strength value decreased obviously, but elongation at break and moisture content increased. In addition, after incorporation of PLA and PBAT during process of TPS100BC0.02CA0.1, their moisture content was improved obviously. From the SEM analysis it could be found that the granule structure of nature starch molecules was disappeared after being plasticized by the high temperature and strong mechanical forces for a long time. When the PLA and PBAT content are less than20and50wt%, they are respectively with continuous phase particle dispersion in TPS. From the Fourier transform infrared (FTIR), citric acid and starch molecules did not produce the esterification reaction. From wide angle X-ray scattering (WAXD) and Differential scanning calorimetry(DSC),starch specimens appear four obvious diffraction peaks which are corresponding to the typical A-type crystallization. And in TPS the original A-type crystallization peaks of starch disappear. TPS, TPS100BC0.02and TPS100BC0.02CA0.1sample appear starch Vn-type crystallization peaks and their peak intensity is bigger and bigger with increased storage time.however, TPS100BC0.02CA0.1sample peak intensity is smaller than TPS andTPS100BC0.02in a fixed time. On the other hand,(TPSiooBC0.02CA0.1)xPLAy and (TPSiooBCo.o2CAo.i)xPBATy series specimens appear starch VH-type crystallization peaks and melting peaks intensity were smaller than TPS, TPSiooBC0.02and TPS100BC0.02CA0.1sample, and they would be significantly reduced with the increase of content of PLA and PBAT...