纤维素醚改性聚L-乳酸的研究

制备了聚L-乳酸（PLLA）与乙基纤雏素（EC）的三氯甲烷混合溶液和PLLA与甲基纤维素（MC）的三氟乙酸混合溶液，并浇膜制备了PLLA／纤雏素醚共混物；采用傅里叶变换红外光谱（FT-IR）、示差扫描量热法（DSC）和X-射线衍射（XRD）等方法表征所得的共混物。PLLA与纤雏素醚之间存在氢键作用，两组分部分相容。随着共混物中纤维素醚含量的增加，共混物的熔点、结晶度和晶体的完整度均会降低。当MC含量高于30％时，可以得到几乎非晶的共混物。因此；纤维素醚可用于改性聚-乳酸，制备不同性能的降解高分子材料。

Study on Poly(L-Lactic Acid) Modified with Cellulose Ethers

Blend films of poly(L-lactic acid) (PLLA) and ethylcellulose (EC) with various composition were prepared by casting from respective chloroform solution, while those of PLLA and methylcellulose (MC) were prepared from respective trifluoroacetic acid solution. The obtained blends were characterized with FT-IR, DSC, and X-ray diffraction. All results suggested that PLLA/EC blends and PLLA/MC blends were liable to form interpolymer hydrogen bonds and were partially miscible, which resulted in the decrease of melt temperature, crystallinity, and crystal perfection of these blends with the increasing EC ratios. Amorphous blends could form as PLLA/MC being less than 70/30. Thus biodegradable PLLA blends with various properties could be prepared by modifying PLLA with cellulose ethers.