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There is an increasing interest in utilizing more sustainable and inherently biodegradable materials alternatives ideally derived from renewable resources for modern material applications, especially in the area of packaging materials. This work employed the polysaccharide alpha-1,3-glucan derived from an enzymatic polymerization process as a functional additive for natural rubber (NR) latex-based coating films. Coating formulations containing NR and 9-50 wt% alpha-1,3 glucan were prepared and then applied to paper substrates at different thicknesses. The effect of coating formulations on the barrier properties (e.g., oxygen, oil, water vapor barrier), the viscosity, and dry and wet tensile properties were investigated. The NR/glucan coatings exhibited outstanding tensile properties and balanced oxygen and oil barrier performance. However, higher glucan loading could be detrimental to moisture barrier. Overall, this study indicated that the NR/glucan coating films are comparable in performance to commercial coating formulations while providing a renewable, potential to be recycled with paper, and biodegradable alternative.

The commercial production of cellulose nanocrystals (CNCs) requires high concentration of sulfuric or other acids such as hydrochloric, phosphoric, and nitric acids. However, these acids and the involved process are corrosive, toxic, energy-intensive, and not environmentally safe. In this work, a batch mixer reactive process that entails high shear was implemented using 1-butyl-3-methylimidazolium chloride (BmimCl) media and molten oxalic acid dihydrate (OA) to produce CNCs from cellulose. Through this, a maximum CNC yield (59 wt%) was obtained with a mixture composition of 1:0.7:0.075 (Cellulose:BmimCl:OA, w/w/w) and a processing time of 2.5 min. Further investigation revealed that the particle size, degree of crystallinity, and thermal stability of the produced CNCs were found to be competitive with those of a commercial CNC product. This study asserts the potential industrial application of an efficient ionic liquid and molten organic acid treatment for CNC production via reactive processing in a batch mixer.

In this work, enzymatic polymerization derived microcrystalline glucan (MCG) polysaccharides fillers were employed as novel sustainable fillers of natural rubber (NR) films. MCG has a designed platelet morphology, with high crystallinity and colloidal stability in aqueous media and rubber lattices. NR films composed of 0–10 phr MCG were then fabricated using dipping and casting processes. The incorporation of MCG in the NR led to a remarkable enhancement in the tear strength, tensile properties, toughness, and an increase in water vapor permeability but a decrease in ethanol permeation. This behavior is appealing in gloves, where high sweat permeation from hands to the environment and limited to no solvent penetration from the environment to the skin is desired. The study indicated that the enzymatically polymerized MCG are effective reinforcing fillers for NR latex and potentially other elastomers offering the potential for appealing physical property improvements.

A novel monomer based, controlled enzymatic polymerization was employed to produce an engineered alpha-1,3 glucan polysaccharide. The structure and material properties of the engineered polysaccharide were characterized using various techniques. The use of such engineered polysaccharide as a reinforcing filler of polymers was evaluated using model polymers. For this, the alpha-1,3 glucan was incorporated into ethylene vinyl acetate co-polymer (EVA) matrices with vinyl acetate content of 32% and 40% via a melt processing fabrication process. Various mechanical and rheological properties of the fabricated composites were evaluated. The effect of vinyl acetate content of the EVA resin on the interaction with alpha-1,3 glucan that result in various performances attributes was also investigated and reported. The incorporation of alpha-1,3 glucan in these EVA composites resulted in the improvement of key composite properties, such as toughness, modulus, wear resistance, and hardness showing the reinforcing potential of these engineered polysaccharides.

Starch is an attractive biomacromolecule for functional materials due to its renewability, biodegradability, amenability for modification, and biocompatibility in mammalian cell lines. In this research, starch was proposed as a modular platform to produce antimicrobial polymer surfaces. Conjugation of biocidal molecules via chemical grafting onto starch (starch-g-biocide) and its antimicrobial properties in poly (lactic acid) (PLA) polymers were investigated. Polyhexamethylene guanidine hydrochloride (PHGH) was synthesized and used as an antimicrobial agent. The grafting was confirmed by FTIR, proton NMR, and elemental analysis. The modified starch was then incorporated into the PLA films at various concentrations, and the antimicrobial efficacy of these films were evaluated against a Gram-positive bacterium, Bacillus subtilis and a Gram-negative bacterium, Escherichia coli. The results showed that the polymer surfaces have high antimicrobial potency when bacteria contact them. This material therefore has great potential for self-decontaminating surfaces, such as medical devices and food packaging applications.