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Mechanical strength, thermal conductivity and electrical breakdown of polypropylene/lignin/kenaf core fiber (PP/L/KCF) composite were studied. PP/L, PP/KCF and PP/L/KCF composites with different fiber and lignin loading was prepared using a compounding process. Pure PP was served as control. The results revealed that tensile and flexural properties of the PP/L/KCF was retained after addition of lignin and kenaf core fibers. Thermal stability of the PP composites improved compared to pure PP polymer. As for thermal conductivity, no significant difference was observed between PP composites and pure PP. However, PP/L/KCF composite has higher thermal diffusivity. All the PP composites produced are good insulating materials that are suitable for building. All PP composites passed withstand voltage test in air and oil state as stipulated in IEC 60641-3 except PP/L in oil state. SEM micrograph showed that better interaction and adhesion between polymer matrix, lignin and kenaf core fibers was observed and reflected on the better tensile strength recorded in PP/L/KCF composite. This study has successfully filled the gap of knowledge on using lignin and kenaf fibers as PP insulator composite materials. Therefore, it can be concluded that PP/Lignin/KCF has high potential as an insulating material.

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An effective statistical tool for increasing and boosting the production of xylanase and pectinase by Bacillus amyloliquefaciens ADI2 during submerged fermentation (SmF) appears to be the response of surface methodology (RSM) using the central composite design (CCD). Optimum production was achieved under fermentation conditions of a temperature of 28 °C, pH of 8.38, inoculum size of 4% (w/v) and agitation speed of 94 rpm for 48 h. The experimental responses demonstrated a near agreement with the expected responses under optimum conditions of independent variables, suggesting the model’s validity. The optimised CCD model had a 1.34-fold, 159 ± 6 U/mL greater xylanase and 5.96-fold, 205 ± 9 U/mL greater pectinase production than the one factor at a time (OFAT) approach. The production of concurrent enzymes of xylanase–pectinase resulted in a ratio of 1:1.3.

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Recently, polymer nanocomposites have been fabricated using carbon nanotubes (CNTs) as reinforcement nanofillers. However, the effect of incorporating CNT/polymer into hybrid composites with natural fibre is not clear. This study investigated the effect of using multi-walled carbon nanotube material (MWCNT) as the nanofiller on the tensile and flexural properties of bamboo/glass fibre hybrid composites. Composites containing various weight fractions of CNTs (0.1 wt.%, 0.3 wt.%, 0.5 wt.%, and 1.0 wt.%) were compared with the control hybrid composites. The hybrid composites were prepared with epoxy resin. The experimental results revealed an increase in the tensile strength of the composites with the addition of up to 0.5 wt.% CNTs (+7.7% over the control hybrid). However, beyond this value, i.e., with 1.0 wt.% CNT additives, the composite strength showed a remarkable decrease (-36.8% compared with the control hybrid). Moreover, introducing CNTs into hybrid composites resulted reduced the flexural properties with increasing weight fractions as low as 8.45% compared with the controls. In sum, the tensile properties increased with the addition of up to 0.5 wt.% CNTs, but there was a decrease in the flexural properties.