Study Of MAH On The Compatibility Of Thermoplastic Starch/Polyethylene In The Presence Of DCP

In order to improve the poor compatibility of starch and PE, find a convenient and feasible way to prepare environmentally friendly materials, and explore low cost biodegradable plastics with good properties, in this paper, we first adopt one-step extrusion technics to prepare biodegradable plastics with good properties. In the presence of dicumyl peroxide (DCP), maleic anhydride(MAH) was used as compatibilizer in the thermoplastic starch(TPS)/polyethylene(PE) blends. The themal plasticization of starch and its compatibilizing modification together with LDPE was accomplished in the single-screw extruder at the same time. Different properties were examined including mechanical properties, thermal properties(by TG), scanning electron microscopy(by SEM), rheological properties, crystallinity properties and water resistance(under different imitated RH environments). The results show that the blends with MAH have better mechanical and thermal properties than those without MAH. When MAH was added with 1% content(based on PE, 50%PE), the tensile strength was improved 14.9%, while the elongation at break was improved 257.2%. By SEM analysis, the addition of MAH improved the mutual disperse of TPS and PE, and there also hadn't the obvious phase interface. So, TPS and PE formed an evenly continuous phase system on the whole. By the rheological analysis, the addition of MAH decreased the flow activation energies, improved the flow behavior of the blends, and further ameliorated the machining properties. The X-Ray diffraction results showed that the crystal structure of starch was destroyed after it was thermal plasticized in the single-screw extruder. The crystal structure of PE didn't show an obvious rule because of the addition of MAH. With the addition of MAH, water resistance of the blends decreased to some extent. The degradation results of the blends showed that the blends had good degradation properties, especially under the photo-oxidation degradation condition.In addition, mechanism of compatibility between TPS and PE during process of the blending extrusion was studied. By dynamic thermal mechanical analysis(DTMA) and Fourier transform infrared spectroscopy(FTIR) analysis, the mechanism of compatibility between TPS and PE was validated. The experiment results showed that MAH had grafted into the PE successfully and improved the compatibility of the TPS/PE blends. Consequently, the blends have different good properties. ...