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An approach of green in situ synthesis single-step method was applied to produce antibacterial paper. The objective was to investigate the effect of precursor addition on the formation of zinc oxide particles using an in situ single-step method. Zinc chloride concentrations of 0.1, 0.3, 0.5, and 0.7 M were prepared and added into a solution of algae extract and bamboo pulp. The prepared pulps were tested and made into handsheets using a papermaking machine based on TAPPI T205 (2006). Morphological observation of treated papers was conducted using a field emission scanning electron microscope (FESEM). An average of 400 to 570 nm zinc oxide spherical-shaped particle was observed on the fibers of paper. The percentage of element composition of the treated paper were 15.08% to 34.08% of zinc and 17.45% to 32.59% of oxygen captured via scanning electron microscopy with energy dispersive X-ray (SEM-EDX) analysis. The crystallinity test was performed using X-ray dispersion (XRD). A higher percentage of precursors exhibited a more amorphous structure. A measurement of more than 30% increment of inhibition zone was obtained from 10.00 to 25.00 mm against S. aureus, S. choleraesuis, and E. coli. Precursors addition of more than 0.3 M would have the most potential to enhance the growth of zinc oxide via in situ preparation, hence providing better antibacterial properties of the prepared papers.

Oil palm empty fruit bunch (EFB), an abundant fiber material obtained after extracting the oil from the strands, is classified as short fiber which needs supporting agent in order to enhance its me...

The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.

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.

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.

Laccases have great biotechnological potential in various industries as they catalyze the oxidation of a broad variety of chemical compounds, diamines, and aromatic amines. The production of laccases by fungi has been broadly studied due to their secretion of enzymes and their growth using cheap substrates. In this study, five native fungi isolates (Dr1, Dr2, Dr4, K5, and K9) were screened for laccase enzyme production. The ability to produce laccase was evaluated based on light green to dark color formation on a potato dextrose agar using 2,2’-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) as an indicator. The highest laccase production was obtained by Dr4, which was identified as Trichoderma muroiana IS1037. Among the different carbon sources tested (rubber wood dust, rice straw, sugar cane bagasse, and oil palm empty fruit bunch), the highest laccase activity (5.84 U/mL) was obtained in submerged fermentation using rubber wood dust as substrate. Laccase production was further enhanced with the addition of 2 mM copper sulfate. In conclusion, the local fungus isolate Trichoderma muroiana IS1037 is a potential fungi-producing laccase that can use rubberwood dust as carbon source.

Recently, xylanase has attracted attention in the pulp and paper industry because of its bleach-boosting properties, which reduces chemical consumption during the bleaching process. Four fungi species, namely Penicillium oxalicum T3.3, Aspergillus niger ATCC 6275, Colletotrichum gloeosporioides, and Pycnoporus sanguineus, were studied to select which fungi can best produce cellulase-poor xylanase using rice straw as a substrate. The fungi were screened for xylanase production based on the clear zone formation on a malt extract agar (MEA) plate containing xylan. P. oxalicum T3.3 and A. niger ATCC 6275 showed greater clear zone formation on the agar plate than the other two studied fungi. These fungi were grown in a liquid medium containing rice straw as the substrate. P. oxalicum T3.3 showed the highest xylanase activity (65.89 U/mL) with lowest carboxymethyl cellulase (CMCase) (1.88 U/mL) and filter paperase (FPase) activity (0.16 U/mL) after four days of fermentation at 30 °C. P. oxalicum T3.3 produced higher xylanase activity when rice straw was used as a substrate compared to commercial xylan. Thus, cellulase-poor xylanase produced from P. oxalicum T3.3 has high potential for biobleaching application in the pulp and paper industry in terms of technical and biological performance and economical aspects.

In this study, blended paper was prepared by blending synthetic polyethylene (PE) via a disintegration technique. The produced paper was targeted to resist water or moisture. Unbleached kenaf whole stem pulp was used as the main source of fibre in making the paper. The pulp was blended with two types of PE: low-branched (LB) and high-branched (HB) polymers. To study the effect of PE addition to the paper, the water absorbency and mechanical properties were characterized. The pulp to PE mixtures were prepared at ratios of 9:1, 8:2, 7:3, 6:4, and 5:5. Scanning electron microscopy (SEM) showed that the PE was melted between the fibre linkages. The Cobb test determined that the blended paper absorbed less than 20 g/m2 of water within 60 s. The best water contact angle successfully achieved was at 84°, which is almost hydrophobic. The mechanical properties, such as tensile strength and tear strength, were in the range of accepted standard requirements. The obtained results indicated that blending via a disintegration technique can be applied in the process of making water-resistant paper. The produced paper is suitable for the manufacturing of water-resistant corrugated packaging materials.

Kenaf (Hibiscus cannabinus L.) is a relatively new industrial crop which has been identified as an alternative source of fiber in the papermaking industry in Malaysia. In this study, experimental unbleached kenaf kraft paper samples were used as a substrate to produce water-resistant paper by employing a special coating. In the preparation of the coating formulation, commercially precipitated calcium carbonate (PCC) was used as the filler, in addition to 0 to 0.32 w/w g of hydrophobic stearic acid (SA). Polymer latex (PL) was added at 0.4 to 0.16 w/w g into the coating compound to control the surface roughness of the samples. The paper morphology was examined by employing a scanning electron microscope (SEM). Hydrophobic kenaf kraft paper prepared in this study had water contact angle (θ) greater than 90°. Hydrophobic paper made with formulation PL4c resulted in the highest value contact angle of 147°. The process of surface coating by dipping increased the water contact angle and this treated paper achieved a high hydrophobic level. For mechanical properties, the coated kenaf paper showed decreasing tensile strength as the addition of stearic acid increased.