淀粉接枝共聚物微球的合成研究

用V(环己烷)∶V(淀粉溶液)=4∶1构成反相悬浮体系,m(Span60)∶m(Tween60)=2∶1复配为分散剂,在60℃下以K2S2O8-NaHSO3引发N,N’-亚甲基双丙烯酰胺(MBAA)与淀粉的接枝共聚,制备了淀粉接枝共聚物微球。正交实验表明,合成共聚微球的较优工艺条件为:淀粉液浓度20%,引发剂用量0.2 g,MBAA用量0.4 g,油水比为3∶1,乳化剂用量1.0 g。用SEM和粒度分析仪对微球形貌和粒度分布进行了研究,用FT-IR对其结构进行了表征,用XRD,TGA对其物性进行了分析。结果显示,共聚物微球形态圆整,平均粒径50.2μm,微球中存在酰氨基结构,与淀粉颗粒相比,结晶度降低,热稳定性提高。

Study on synthesis of starch graft copolymer microspheres

Using cyclohexane and starch solution as inverse suspension with a ratio of V(cyclohexane) ∶V(starch solution)=4 ∶1,starch solution as aqueous phase,Span80 and Tween60 as complex surfactant with a ratio of m(Span60) ∶m(Tween60)=2 ∶1,the starch graft copolymer microspheres were synthesized by inverse suspension polymerization with N,N'-methylenebisacrylamide and soluble starch,using K2S2O8-NaHSO3 as initiator,under 60 ℃.The starch graft copolymer were characterized by SEM,FT-IR spectroscopy,X-ray diffraction(XRD),granularity analyzer and thermogravimetric analysis(TGA).The results show that the starch graft copolymer microspheres with acylamino are spherical and even distributing particulates with smooth surface,the average diameter of the product is about 50.2 μm.The crystallinity of graft copolymer microspheres decreased and the thermal stability increased in comparison with starch.The experiments showed that the optimum condition were as follows:concentration of starch solution 20%,dosage of initiator MBAA and emulsifier 0.2 g,0.4 g,1.0 g respectively,volume ratio of oil phase to aqueous 3 ∶1.