The Preparation And Properties Of Crosslinked Starch/Polycaprolactone Blends

The starch was crosslinked with 2, 4, 6, 8ml crosslinking agent (chloroepoxy propane) per 100g of the starch and the starch of different degree of crosslinking were obtained. Then different compositions of crosslinked starch/polycaprolactone were blended using the extruder, adding plasticizing agent .The films were prepared by using the plant curing machine. The degree of crosslinking of starch was determined by measuring the sedimentation constant of starch and the IR spectrum indicated the structure change of crosslinked starch. The result shows: With the chloroepoxy propane increasing, the degree of crosslinking of starch increased and the IR spectrum confirmed it.Rheology of melt system was determined using XLY- II capillary rheometer. The influences of the temperature, shearing stress, the content of polycaprolactone, the use level of plasticizer on the melt system's apparent viscosity were studied. The result shows: the capillary behavior of the modified Starch/Polycaprolactone Blends accorded with Ostwald-Dewaele formulat_w =K·γ_w~n, and n<1,which indicated the blend was pseudoplastic fluid; With the increase of temperature , shearing stress, the content of PCL and the use level of plasticizer, the melt system's apparent viscosity all declined.; Finally, the relation between temperature and the melt system's apparent Viscosity fulfilled Arrheinus formula, but the relation deviated from the formula a little bit when the use level of glycerol is more than 40%.The films were prepared by using the plant curing machine. The mechanical property of the samples was tested using RGT-2 electronic stretcher. The influences of the content of polycaprolactone, the use level of plasticizer and the degree of crosslinking of starch on the film's mechanical property were studied. The result shows: the use level of plasticizer had obvious influences on the films' mechanical characters. With the use level of plasticizer increasing, the film's the tensile strength dropped, while percent elongation rised. Glycerol had more influence on the percent elongation than water. And the content of polycaprolactone of system is more, the mechanical property is better. In addition , the moderate crosslinking of starch could improve the mechanical property of the film.According to GB1034—70, the influences of the content of polycaprolactone, the use level of plasticizer and the degree of crosslinking of starch on Water absorption of the samples were studied. The result shows that the content of polycaprolactone could obviously improve the film's water resistance. In addition , the moderate crosslinking of...