Kraft lignin as filler in PLA to improve ductility and thermal properties
Kraft lignin as filler in PLA to improve ductility and thermal properties
复制标题
DOI：
10.1016/j.indcrop.2015.01.055
复制
发表时间：
2015-10-15
影响因子：
5.9
通讯作者：
Labidi, Jalel
中科院分区：
文献类型：
--
作者：
Gordobil, Oihana;Delucis, Rafael;Labidi, Jalel
以硫酸盐木质素(KL)和乙酰化硫酸盐木质素(AkL)为填料，在200℃下用挤出法制备了不同浓度(0.5%、1%、5%、10%和20%)的聚乳酸复合材料，并用高效液相色谱、红外光谱、凝胶渗透色谱(GPC)、差示扫描量热法(DSC)和热重分析(TGA)对两种木质素进行了表征。KL的灰分含量仅为0.3%，相对分子质量约为2000g/mol。酯化反应增加了木质素的相对分子质量，降低了木质素的多分散性。与未改性硫酸盐木质素相比，Akl具有较低的玻璃化转变温度和较高的热稳定性。木质素含量提高了聚乳酸的热稳定性，两种木质素的加入都提高了聚乳酸的热稳定性。通过测量接触角来评价木质素对聚乳酸疏水性的影响。为了了解木质素在聚乳酸中的作用，还对不同材料的力学性能进行了研究。两种木质素的低浓度对最大强度影响不大，但显著降低，特别是在KL含量为10%和20%的复合材料中，断裂伸长率随加入低含量的Akl而增加，当两种木质素含量较高时，材料变得非常脆性。(C)2015爱思唯尔B.V.保留所有权利。
Kraft lignin (KL) and acetylated Kraft lignin (AKL) were used as filler for the elaboration of composites with poly(lactic acid) (PLA) in different concentrations (0.5, 1, 5, 10 and 20%) by extrusion method at 200 degrees C. Characterization of both lignins has been performed using HPLC, FT-IR, GPC, DSC and TGA. KL presented only 0.3% of ash content and molecular weight around 2000 g/mol. The esterification increased the molecular weight and decreases the polydispersity of the lignin (AKL). Also, AKL had lower T-g and higher thermal stability than unmodified Kraft lignin. Lignin content increased the thermal stability of PLA, with the addition of both types of lignins. Contact angle was measured to assess the change in the hydrophobicity of PLA with the addition of lignins. Mechanical properties of different materials were also investigated in order to know the effect of lignin addition in PLA. Maximum strength was not severely affected at low concentrations of both lignins, but it decreased dramatically, especially in composites with 10 and 20% of KL Elongation at break increased with the addition of low contents of AKL, at high content of both lignins the material becomes quite brittle. (C) 2015 Elsevier B.V. All rights reserved.