纤维素内塑化材料的制备及性能

用微波辐射法快速合成了纤维素长链脂肪酸酯。通过对改性产物的红外光谱及核磁共振光谱表征,证明柔性脂肪酸酯基引入了纤维素骨架。对溶液浇铸法所得薄膜材料的耐水性、玻璃化温度(Tg)、热稳定性、拉伸强度及断裂伸长率进行了分析测定,探讨了取代度对材料性能的影响。结果表明,改性材料表面具有良好的疏水性质,其接触角均在90°左右;由于柔性酯基链的引入,所制备的纤维素改性薄膜具有一定的内塑化性能。取代度为1.8的样品,其Tg为153℃,起始分解温度为198℃,断裂伸长率为50%,拉伸强度约为12 MPa,与线性低密度聚乙烯相当。

Internal Plasticization of Cellulose and Property Characterization

This paper demonstrated the esterification of cellulose with long chain carboxylic acid in a homogeneous phase by microwave irradiation.Partially derivatized celluloses were characterized with the aid of FT-IR and NMR measurements.The influences of the degrees of substitution(DS) on the properties of films by casting were studied.The results show that the contact angle of all products is nearly 90°,decomposition onset at 198 ℃,Tg=153 ℃,elongation=50%,and the tensile strength of the film with DS=1.8(～12 MPa) is equivalent to these obtained for linear low-density polyethylene.