Bacterial nanocellulose and softwood pulp for composite paper

Scaling biosynthesis of bacterial nanocellulose (BNC) allowed samples of composite paper with an increased proportion of BNC to be obtained. This work aims to study BNC samples and bleached soft wood kraft pulp (BSKP) composite paper with a ratio of components varying across a wide range: 10:90, 30:70, 50:50, 60:40, 70:30, 90:10. The method of paper manufacturing was chosen based on the determinations of strength and deformation properties of composite samples with the BNC:BSKP ratio of 20:80. Surface application of BNT on BSKP handsheet provided for an increase in the strength values (tear resistance – by 37%, burst index – by 17%) and deformation characteristics (tension stiffness – by 66%, fracture work – by 8%, breaking length – by 4%) compared to a reference sample. The formation of composites is confirmed in all samples. Scanning electron spectroscopy revealed that paper composites comprise interlaced micro BSKP and nano BNC fibres. As the proportion of BNC in composites elevated, densification of the structure was observed due to an increased fraction of cross-linked nanosized elements. IR spectroscopy indicated the resemblance of cellulose structure in all samples. It was found that an increase in the degree of polymerisation of composite paper is directly proportional to an increase in the BNC amount in the samples. The filtering ability of composite paper samples against microorganisms in the culture liquid of the Medusomyces gisevii Sa-12 producer was studied. It should be noted that yeast retention is achieved with 70% BNC in the paper composite. The presented properties of the new material determine prospects for its use in filtering microorganisms.

Composite paper from an agricultural waste of bagasse sugarcane and pineapple leaf fibre: a novel random and multilayer hybrid fibre reinforced composite paper

Bagasse sugarcane (BSC) has low fibre strength due to low cellulose content. Hence, by adding a strong secondary fibre that is high in cellulose such as pineapple leaf fibre (PALF), the fibre strength of the system can be improved. High portion of PALF decreased the composite paper performance because the high composition of PALF tends to produce flocs and agglomerates fibres. The arrangement of the fibres in composite paper should be improved so that this agglomerate’s effect could be overcome. A novel multilayer hybrid fibre composite was used. BSC/PALF with several hybrid ratios was studied in terms of the mechanical and moisture properties of the produced paper sheet and the results showed that multilayer hybrid composite paper produced higher in hybrid composite paper’s properties compared with random hybrid composite paper. The colour of multilayer hybrid fibre composite paper resembled the natural bright colour of BSC and the multilayer hybrid fibre composite paper also shown a slightly low weight loss percentage compared with the random hybrid fibre composite paper after 60 days of soil burial test. As a conclusion, multilayer hybrid fibre composite produced the stronger interfibre bonding and overcome the agglomerate’s effect between BSC/PALF compared with random hybrid fibre composite.

Evaluation of the Antioxidant Activity, Deodorizing Effect, and Antibacterial Activity of ‘Porotan’ Chestnut By-Products and Establishment of a Compound Paper

Chestnuts are widely cultivated for their edible portion (kernel), whereas the non-edible parts are discarded. To enable the utilization of the by-products of processed chestnuts, we separated them into green and brown burs, shells, inner skin, and leaves, and analyzed the bioactive properties of the ground components. We also created a composite paper, comprising the inner skin, and examined its deodorant properties. It was revealed that the inner skin had the highest functionality and showed potent antioxidant, antibacterial, and deodorant properties. Furthermore, when we produced a paper, containing 60% inner skin, and examined its deodorant properties, we found that it was highly effective in deodorizing ammonia and acetic acid gases. These results show that the inner skin of chestnuts is a promising material for developing hygiene and other products.