Valorization of low-value cowpea lignocellulosic fibres to produce biodegradable plastics

The research investigates cowpea lignocellulosic fibres as a low-value biomaterial to produce biodegradable plastics for application in packaging and agriculture. Different products were produced, mainly cellulose fibres, and bio-composite materials (injection moulded, films and foams). The three research chapters focused on the different materials as outlined below:

The effect of extrusion as an alternative pre-treatment to conventional alkaline pre-treatment followed by bleaching on the production of cellulose fibres from cowpea lignocellulosic fibres was investigated. Different characterization techniques such as, FTIR, XRD, SEM and TGA were used to compare the quality of the cellulose fibres obtained by the two different methods.
In this section, we investigated cowpea lignocellulosic fibres as a filler in a PBSA/PHBV blend matrix, using already exising polymer processing techniques, such as extrusion, followed by injection moulding and extrusion film casting. Vaarious thermal (DSC, TGA and DMA), mechanical and barrier properties were used to evaliuate the effect of fibre addition on the properties of injection moulded bio-composite and bio-composite films. Moreover, to compare injection moulded bio-composites with the bio-composite films.
In this section, the effect of cowpea lignocellulosic fibres as a bio-based filler on the foam properties of PBSA was investigated. Different characterization techniques, such as thermal, thermomechanical, and morphological were used to evaluate the effect of cowpea fibres on foam properties of PBSA.

Overall, the different techniques employed demonstrated that low-value cowpea lignocellulosic fibres cab be used as a biomaterial to produce biodegradable packaging materials, such as cellulose fibres and bio-composites (injection moulded, films and foams). These developed materials can serve as alternative to petroleum-based and non-biodegradable plastics in some applications.

本研究探讨以豇豆木质纤维素纤维作为一种低价值生物质材料，用于生产可生物降解塑料，并应用于包装和农业领域。研究主要产生了不同产品，主要包括纤维素纤维和生物复合材料（注塑、薄膜和泡沫）。三个研究章节分别聚焦于以下不同材料：

研究了挤压作为传统碱法预处理后漂白的一种替代预处理方法，对从豇豆木质纤维素纤维中生产纤维素纤维的影响。采用不同的表征技术，如傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）和热重分析（TGA），以比较两种不同方法获得的纤维素纤维的质量。

在本节中，我们探讨了将豇豆木质纤维素纤维作为填料应用于PBSA/PHBV共混基质，利用现有的聚合物加工技术，如挤压、注塑和挤出薄膜铸造。通过使用多种热性能（DSC、TGA和DMA）、力学性能和阻隔性能评估纤维添加对注塑生物复合材料和生物复合材料薄膜性能的影响。此外，为了比较注塑生物复合材料与生物复合材料薄膜。

在本节中，研究了豇豆木质纤维素纤维作为生物基填料对PBSA泡沫性能的影响。采用不同的表征技术，如热性能、热机械性能和形貌学，以评估豇豆纤维对PBSA泡沫性能的影响。

总体而言，所采用的不同技术表明，低价值的豇豆木质纤维素纤维可作为生物材料，用于生产可生物降解的包装材料，如纤维素纤维和生物复合材料（注塑、薄膜和泡沫）。这些开发出的材料可作为某些应用中石油基和非生物降解塑料的替代品。