乙基纤维素共混改性聚乳酸的研究

将聚L-乳酸(PLLA)和乙基纤维素(EC)的三氯甲烷溶液以不同比例混合浇膜制备出的PLLA-EC共混物膜,采用红外光谱(FT-IR)、示差扫描量热法(DSC)和X-射线衍射等方法对共混物膜进行了表征。结果表明:PLLA与EC两种聚合物间存在着氢键作用,两种组分部分相容;PLLA与EC的比例对共混物的结晶性能有极大影响,随着EC含量的增加,共混物中PLLA结晶的熔点降低,结晶度、晶体尺寸和晶体完美度均降低;EC的含量对PLLA-EC共混物在磷酸缓冲溶液中的降解速率也有显著影响,当EC含量高于30%时,PLLA-EC共混物的降解速率会迅速增大。

A Study on Poly(L-Lactic Acid) Blended with Ethylcellulose

Blend films of poly(L-lactic acid)(PLLA) and ethylcellulose(EC) with various compositions were prepared by casting from respective chloroform solution.The obtained blends were characterized with FT-IR,DSC,and X-ray diffraction.All results showed that PLLA and EC were liable to form interpolymer hydrogen bonds,and PLLA and EC were partially miscible.The crystal formation and crystal perfection of PLLA-EC blend relied on PLLA/EC ratios,which resulted from interpolymer hydrogen bonds of PLLA with EC.The degradation of blend in phosphoric buffer was great affected by PLLA-EC ratios.The(degradation) of PLLA-EC blend increased greatly with the ethylcellulose contents as PLLA-EC being less than 70/30.Thus PLLA-EC blends with various properties may be used as(biodegradable) polymers.