Abstract:
Bio-fillers are intensively studied for advanced polymer composite circular design and production. In this context, the algal biomass may be considered an important and relatively low-cost resource, when harvested as a by-product from wastewater treatment plants. The biomass of the algal species Chlorella vulgaris is frequently used in this type of environmental process, and its macro constituents\' composition ranges from around 15-25% carbohydrates, 10-20% lipids, and 50-60% proteins. Poly (styrene-butadiene-styrene) (SBS) copolymers have a matrix composed of glassy polystyrene domains connected by flexible polybutadiene segments. Although the physical-mechanical properties of SBS copolymers recommend them for many industrial applications, they have the drawback of low biodegradability. This study aimed to assess the aerobic biodegradability of polymer composites by integrating biomass from Chlorella vulgaris at varying mass percentages of 5, 10, and 20% into SBS copolymer composites. Biodegradation tests were conducted under industrial composting conditions (58 °C and 50% relative humidity) for 180 days. The biodegradability of materials was evaluated by measuring the CO2 produced in each vessel during the study period. Potential correlations between the amount of carbon dioxide released and the percentage of biomass added to the polymer matrix were examined. Structural and morphological changes were assessed using Fourier Transform infrared spectroscopy (FTIR), thermal analysis (DSC), and scanning electron microscopy (SEM). Physical and chemical testing revealed a decrease in sample density after the industrial composting test, along with noticeable changes in melt flow index (MFI). The observed physical and chemical changes, coupled with FTIR, SEM, and DSC data, indicate increased cross-linking and higher porosity in biodegraded polymer structures with higher biomass content. This behavior is likely due to the formation of cross-linked connections between polymer chains and polypeptide chains resulting from protein degradation, enhancing connections between polystyrene units facilitated by peptide bonds with the benzene units of the styrene blocks within the polymer matrix.
摘要:
对生物填料进行了深入研究,用于先进的聚合物复合材料圆形设计和生产。在这种情况下,藻类生物质可能被认为是一种重要且相对低成本的资源,当从污水处理厂作为副产品收获时。藻类小球藻的生物量经常用于这种类型的环境过程中,它的宏观成分组成范围从大约15-25%的碳水化合物,10-20%脂质,和50-60%的蛋白质。聚(苯乙烯-丁二烯-苯乙烯)(SBS)共聚物具有由通过柔性聚丁二烯链段连接的玻璃状聚苯乙烯域组成的基质。尽管SBS共聚物的物理机械性能推荐它们用于许多工业应用,它们具有生物降解性低的缺点。这项研究旨在通过将来自小球藻的生物质以5、10和20%的不同质量百分比整合到SBS共聚物复合材料中来评估聚合物复合材料的需氧生物降解性。在工业堆肥条件(58°C和50%相对湿度)下进行180天的生物降解测试。通过测量研究期间每个容器中产生的CO2来评估材料的生物降解性。研究了释放的二氧化碳量与添加到聚合物基质中的生物质百分比之间的潜在相关性。使用傅里叶变换红外光谱(FTIR)评估结构和形态变化,热分析(DSC),和扫描电子显微镜(SEM)。物理和化学测试表明,工业堆肥测试后样品密度降低,随着熔体流动指数(MFI)的显著变化。观察到的物理和化学变化,再加上FTIR,SEM,和DSC数据,表明具有较高生物质含量的生物降解聚合物结构中交联增加和孔隙率较高。这种行为可能是由于蛋白质降解导致的聚合物链和多肽链之间的交联连接的形成,增强通过肽键促进的聚苯乙烯单元与聚合物基质内苯乙烯嵌段的苯单元之间的连接。