碳酸钙含量与粒径对聚对苯二甲酸己二酸丁二醇酯/聚乳酸共混物的力学与散发性能的影响

Effects of the Content and Particle Size of Calcium Carbonate on the Mechanical and Emanation Properties of Poly(butylene terephthalate adipate)/Polylactic Acid Blends

采用熔融共混法制备苯二甲酸-己二酸丁二醇酯(PBAT)、聚乳酸(PLA)和碳酸钙的共混物,并探究碳酸钙种类与粒径对于共混物力学性能与散发性能的影响。结果表明,随着碳酸钙1T-JI(累计粒度分布百分数达到50%时所对应的粒径D_(50)为1μm)含量的增加,共混物的拉伸强度逐渐下降。碳酸钙的D 50增大至5μm后,共混物的断裂伸长率明显下降。在添加质量分数5%~10%的1T-JI时,落镖冲击强度保持得较好,进一步提升碳酸钙含量以及调控碳酸钙粒径,落镖冲击强度大幅度降低。质量分数0~5%的1T-JI添加时,随着碳酸钙含量的增加,气味等级和顶空法总挥发性有机化合物(TVOC)逐步上升。共混物有机挥发物(VOC)中的苯类的物质维持较低的水平,而总碳含量(C6~C16)随着碳酸钙含量的增加以及粒径的提高而逐步的上升,5T-25%的共混物的总碳含量相对于PBAT/PLA共混物提高了61.9%。随着碳酸钙含量的增加以及粒径的提高,雾化测试后玻片的光泽度保持率逐渐下降,5T-25%的共混物相对于PBAT/PLA共混物下降了47.7%。进一步分析玻片可以看出,5T-25%样品对应的玻片有非常明显的“油污”。本研究对推广生物降解材料的应用有理论支撑,对塑料软包装领域的绿色转型有重要的研究价值。

The blends of poly(butylene terephthalate adipate)(PBAT),polylactic acid(PLA)and calcium carbonate were prepared by melt blending method,and the effects of the type and particle size of calcium carbonate on the mechanical and emanation properties of the blends were investigated.The results indicate that as the content of calcium carbonate 1T-JI(with a D 50 particle size of 1μm,where D_(50)is the diameter corresponding to 50%cumulative particle size distribution)increases,the tensile strength of the blends gradually decreases.Once the D 50 of calcium carbonate increases to 5μm,the elongation at break of the blends markedly decreases.When the 1T-JI mass fraction is 5%-10%,the dart strength is maintained well.After further increasing the calcium carbonate content and regulating the calcium carbonate particle size,the falling dart strength decreases significantly.When the 1T-JI mass fraction is 0-10%,with the increase of the calcium carbonate content,the odor grade and headspace total volatile organic compounds(TVOCs)increase gradually.The benzene in the organic volatile organic compounds(VOCs)of the blends remains low,while the total carbon content(C6-C16)gradually increases with the increase of calcium carbonate content and particle size,and the total carbon content of 5T-25%blend increases by 61.9%relative to that of PBAT/PLA blend.The slide glossiness gradually decreases with the increase of calcium carbonate content and particle size,with a 47.7%decrease for the 5T-25%blend relative to the PBAT/PLA blend.Further analysis of the slides shows that the slide corresponding to the 5T-25%sample has very obvious“oil stains”.This study has theoretical supports for the application promotions of biodegradable materials,and has an important research value for the green transformation in the plastic flexible packaging field.