花生壳微晶纤维素改性聚乳酸的性能及机理  

Properties and Mechanism of Poly(lactic acid)Modified by Peanut Shell Microcrystalline Cellulose

作　　者：宫贵贞[1] GONG Guizhen(School of Materials and Chemical Engineering,Xuzhou University of Technology,Xuzhou,Jiangsu 221018,China)

机构地区：[1]徐州工程学院,材料与化学工程学院,江苏徐州221018

出　　处：《塑料》2024年第1期98-102,124,共6页Plastics

基　　金：徐州工程学院科研课题(XKY2018124)。

摘　　要：花生壳采用碱解、酸解、脱色等处理后制得微晶纤维素(MCC),将其作为填料加入到聚乳酸(PLA)中,通过溶液流涎成膜的方法制得不同MCC含量的MCC/PLA复合膜。分析了碱解过程中氢氧化钠浓度对MCC收率的影响、MCC含量对MCC/PLA复合膜性能的影响及其作用机理。利用傅里叶变换红外光谱仪(FTIR)、差示扫描量热仪(DSC)、扫描电子显微镜(SEM)、万能力学试验机等对MCC及MCC/PLA复合膜结构及性能进行表征和分析。结果表明,花生壳通过碱解、酸解、脱色等处理,将木质素等物质大量去除,制得MCC;MCC的加入,影响了PLA结晶结构的规整度及完善程度,降低了复合膜的熔融温度;随着MCC含量的增加,MCC/PLA复合膜的拉伸强度和断裂伸长率呈先增加后降低的趋势,均大于纯PLA的拉伸强度和断裂伸长率。当MCC的含量为5.6%时,MCC/PLA复合膜的拉伸强度为36.5 MPa,断裂伸长率达到最大值1.7%,与纯PLA相比,分别提高了52.1%和30.8%;SEM结果表明,该含量的MCC在PLA中分散均匀,复合膜光滑平整。Microcrystalline cellulose(MCC)was prepared from peanut shell by alkali hydrolysis,acid hydrolysis and decolorization,which was added into polylactic acid(PLA)as filler.MCC/PLA composite membranes with different contents of MCC were prepared by solution casting.The effect of sodium hydroxide concentration on the yield of MCC,and MCC content on the properties of MCC/PLA composite membrane and mechanism were investigated.The properties and structures of microcrystalline cellulose and composite membrane were characterized and analyzed by fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),scanning electron microscope(SEM)and universal mechanical testing machine.The results showed that lignin and other substances could be removed from peanut shell by alkali hydrolysis,acid hydrolysis and decolorization;The addition of MCC affects the regularity and perfection of the crystalline structure of polylactic acid,and reduces the melting temperature of the composite membrane;With the increase of MCC content,the tensile strength and elongation at break of MCC/PLA composite film increased first and then decreased,which were greater than those of pure PLA.When the addition of MCC was 5.6%,the tensile strength of MCC/PLA composite film was 36.5 MPa and the elongation at break was 1.7%,which was 52.1%and 30.8%,higher than that of peat PLA film,respectively.SEM showed that MCC was evenly dispersed in PLA at this content,and the composite film was smooth and flat.

关 键 词：聚乳酸 花生壳 微晶纤维素 复合膜 性能 

分 类 号：TQ322.3[化学工程—合成树脂塑料工业]