David Grégoire, Gontard Nathalie, Angellier-Coussy Hélène
JRU IATE 1208-CIRAD/INRA/Montpellier Supagro/University of Montpellier, 2 Place Pierre Viala, Bat 31, CEDEX 01, F-34060 Montpellier, France.
Polymers (Basel). 2019 Jan 24;11(2):200. doi: 10.3390/polym11020200.
Materials that are both biodegradable and bio-sourced are becoming serious candidates for substituting traditional petro-sourced plastics that accumulate in natural systems. New biocomposites have been produced by melt extrusion, using bacterial polyester (poly(3-hydroxybutyrate3-hydroxyvalerate)) as a matrix and cellulose particles as fillers. In this study, gas-phase esterified cellulose particles, with palmitoyl chloride, were used to improve filler-matrix compatibility and reduce moisture sensitivity. Structural analysis demonstrated that intrinsic properties of the polymer matrix (crystallinity, and molecular weight) were not more significantly affected by the incorporation of cellulose, either virgin or grafted. Only a little decrease in matrix thermal stability was noticed, this being limited by cellulose grafting. Gas-phase esterification of cellulose improved the filler's dispersion state and filler/matrix interfacial adhesion, as shown by SEM cross-section observations, and limiting the degradation of tensile properties (stress and strain at break). Water vapor permeability, moisture, and liquid water uptake of biocomposites were increased compared to the neat matrix. The increase in thermodynamic parameters was limited in the case of grafted cellulose, principally ascribed to their increased hydrophobicity. However, no significant effect of grafting was noticed regarding diffusion parameters.
兼具生物可降解性和生物源性的材料正成为替代在自然系统中积累的传统石油基塑料的有力候选材料。通过熔融挤出制备了新型生物复合材料，使用细菌聚酯（聚（3-羟基丁酸酯-3-羟基戊酸酯））作为基体，纤维素颗粒作为填料。在本研究中，用棕榈酰氯对纤维素颗粒进行气相酯化，以改善填料与基体的相容性并降低湿度敏感性。结构分析表明，无论是原始纤维素还是接枝纤维素的加入，对聚合物基体的固有性能（结晶度和分子量）的影响都不显著。仅观察到基体热稳定性略有下降，这受到纤维素接枝的限制。如扫描电子显微镜横截面观察所示，纤维素的气相酯化改善了填料的分散状态以及填料/基体界面的粘附性，并限制了拉伸性能（断裂应力和应变）的下降。与纯基体相比，生物复合材料的水蒸气透过率、吸湿性和液态水吸收率均有所提高。对于接枝纤维素，热力学参数的增加有限，这主要归因于其疏水性的增加。然而，接枝对扩散参数没有显著影响。
