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通过异氰酸酯与端羟基聚己内酯反应制备端异氰酸酯基预聚体,再接枝到淀粉纳米晶表面,制备了端基分子量可控的聚己内酯接枝淀粉纳米晶。分别用FTIR和1H NMR对所制备的聚己内酯接枝淀粉纳米晶进行表征,结果表明,有少量聚己内酯接枝到淀粉纳米晶表面。XRD结果表明,接枝了少量聚己内酯后的淀粉纳米晶的晶型和结晶度与未接枝的淀粉纳米晶基本一致。聚己内酯接枝淀粉纳米晶的熔融温度由115℃左右提高到122℃左右,并且温度范围变宽。浸润性实验表明,聚己内酯接枝淀粉纳米晶与水不浸润,其表面已具有疏水性。聚己内酯仅接枝在淀粉纳米晶的表面,改善了淀粉纳米晶表面的疏水性能和与聚酯类聚合物的界面相容性。聚己内酯接枝淀粉纳米晶有望用于可降解聚酯类高分子材料,如聚乳酸(PLA)、聚己内酯(PCL)、聚丁二酸丁二醇酯(PBS)等,改善其力学性能和生物降解性能等。
Polyiscaprolactone grafted starch nanocrystals with controlled molecular weight were prepared by the reaction of isocyanate with hydroxyl-terminated polycaprolactone to prepare isocyanate-terminated prepolymer and then grafted onto the surface of starch nanocrystals. The prepared polycaprolactone grafted starch nanocrystals were characterized by FTIR and 1H NMR respectively. The results showed that a small amount of polycaprolactone was grafted on the surface of starch nanocrystals. The XRD results showed that the crystallinity and crystallinity of the starch nanocrystals grafted with a small amount of polycaprolactone were basically the same as that of the non-grafted starch nanocrystals. Polycaprolactone grafted starch nanocrystals melt temperature increased from about 115 ℃ to about 122 ℃, and broaden the temperature range. The results of wettability show that the polycaprolactone grafted starch nanocrystals are not wetted with water and their surface is already hydrophobic. Polycaprolactone grafted only on the surface of starch nanocrystals, improving the hydrophobic properties of starch nanocrystals and interfacial compatibility with polyester polymers. Polycaprolactone grafted starch nanocrystals are expected to be used in biodegradable polyester polymer materials such as polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS) Its mechanical properties and biodegradability and so on.