The effects of microbial pretreatment on hemp fibres were evaluated after microbial retting using the white rot fungi Ceriporiopsis subvermispora and Phlebia radiata Cel 26 and water retting. Based on chemical composition, P. radiata Cel 26 showed the highest selectivity for pectin and lignin degradation and lowest cellulose loss (14%) resulting in the highest cellulose content (78.4%) for the treated hemp fibres. The pectin and lignin removal after treatment with P. radiata Cel 26 were of the order 82% and 50%, respectively. Aligned epoxy-matrix composites were made from hemp fibres defibrated with the microbial retting to evaluate the effects on their ultrastructure. SEM microscopy of the composites showed low porosity on the fibre surfaces after defibration with P. radiata Cel 26 and C. subvermispora indicating good epoxy polymer impregnation. In contrast, fibres treated by water retting and the raw hemp fibres were badly impregnated due to porosity caused by surface impurities such as epidermis and other pectin rich plant cells. The pectin and lignin mainly located in the outer part of the fibres were assumed to be extracted and degraded by pectinase and peroxidase enzymes produced by the fungi.
|Journal||Proceedings of the Risø International Symposium on Materials Science|
|Publication status||Published - 2013|
|Event|| 34th Risø International Symposium on Materials Science: Processing of fibre composites – challenges for maximum materials performance - Technical University of Denmark, Risø Campus, Roskilde, Denmark|
Duration: 2 Sep 2013 → 5 Sep 2013
|Conference||34th Risø International Symposium on Materials Science|
|Location||Technical University of Denmark, Risø Campus|
|Period||02/09/2013 → 05/09/2013|