聚乳酸/乙酰化纳米纤维素薄膜制备及性能研究
Preparation and characterization of PLA/acetylated nanocellulose films
-
摘要: 为改善聚乳酸(PLA)薄膜的力学及阻隔性能,采用纳米纤维素(NCC)对其进行改性。以微晶纤维素(MCC)为原料,用硫酸法制备NCC,进而制备乙酰化纳米纤维素(ANCC),然后将PLA与ANCC按不同比例混合后制备复合薄膜。采用透射电子显微镜(TEM)、傅里叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)对其微观结构和形态进行观测。采用拉伸仪和氧气透过率仪对其力学和气体阻隔性能进行分析。结果表明,使用酸法制备的纳米纤维素长度为100~200 nm,直径范围为10~20 nm。乙酰化处理对纳米纤维素的外观形态没有明显改变。与纯聚乳酸膜相比,ANCC添加量为1%时制备的复合薄膜的拉伸强度增加了29.09%,进一步增加ANCC含量则会导致复合薄膜力学性能下降。添加ANCC有效降低了复合薄膜的氧气透过量,ANCC添加量为0.5%时,薄膜的氧气透过率与纯PLA薄膜相比降低42%。添加ANCC对于薄膜的透光率和雾度没有明显影响。Abstract: In order to improve the mechanical and barrier properties of polylactic acid( PLA) film,nanocellulose( NCC) was added into it.The microcrystalline cellulose( MCC) was used to prepare NCC with sulfuric acid method,and then the NCC was modified to gain the acetylated nanocellulose( ANCC). The composite films with different ratio of ANCC/PLA were prepared by solvent casting method. The microstructure and morphology of films were observed by TEM,FTIR and SEM. The tensile tester and oxygen transmission tester were applied to analyze the mechanical and gas barrier properties of films.The results showed that,the length of the single nanocellulose fiber was in the range of 100 to 200 nm,and the diameter was in the range of 10 to 20 nm.The Acetylation had little effect on the fiber micromorphology. Compared with pure PLA film,the tensile strength of the composite film with 1%ANCC increased by 29.09%,but the tensile strength was declined with the further increase of ANCC was content.The oxygen transmittance rate of the composite film with 0.5% ANCC was decreased by 42%. The addition of ANCC had no significant effect on the transparence and haze.
下载: