Many concerns are being expressed about the biodegradability, biocompatibility, and long-term viability of polymer-based substances. This prompted the quest for an alternative source of material that could be utilized for various purposes. Starch is widely used as a thickener, emulsifier, and binder in many food and non-food sectors, but research focuses on increasing its application beyond these areas. Due to its biodegradability, low cost, renewability, and abundance, starch is considered a “green path” raw material for generating porous substances such as aerogels, biofoams, and bioplastics, which have sparked an academic interest. Existing research has focused on strategies for developing biomaterials from organic polymers (e.g., cellulose), but there has been little research on its polysaccharide counterpart (starch). This review paper highlighted the structure of starch, the context of amylose and amylopectin, and the extraction and modification of starch with their processes and limitations. Moreover, this paper describes nanofillers, intelligent pH-sensitive films, biofoams, aerogels of various types, bioplastics, and their precursors, including drying and manufacturing. The perspectives reveal the great potential of starch-based biomaterials in food, pharmaceuticals, biomedicine, and non-food applications.

/pdf/valorization-of-starch-to-biobased-materials-a-review-3bgl3tz3.pdf

Valorization of Starch to Biobased Materials: A Review

Nature-inspired construction of iridescent CNC/Nano-lignin films for UV resistance and ultra-fast humidity response.

Plant-based proteins are considered to be one of the most promising biodegradable polymers for green packaging materials. Despite this, the practical application of the proteins in the packaging industry on a large scale has yet to be achieved. In the following review, most of the data about plant protein-based packaging materials are presented in two parts. Firstly, the crude protein content of oilseed cakes and meals, cereals, legumes, vegetable waste, fruit waste, and cover crops are indexed, along with the top global producers. In the second part, we present the different production techniques (casting, extrusion, and molding), as well as compositional parameters for the production of bioplastics from the best protein sources including sesame, mung, lentil, pea, soy, peanut, rapeseed, wheat, corn, amaranth, sunflower, rice, sorghum, and cottonseed. The inclusion of these protein sources in packaging applications is also evaluated based on their various properties such as barrier, thermal, and mechanical properties, solubility, surface hydrophobicity, water uptake capacity, and advantages. Having this information could assist the readers in exercising judgement regarding the right source when approving the applications of these proteins as biodegradable packaging material. 

https://www.mdpi.com/2073-4360/14/5/1065/pdf?version=1646734790

Comparison of Protein Content, Availability, and Different Properties of Plant Protein Sources with Their Application in Packaging

Global environmental concerns, as well as the rapid depletion of non-renewable fossil fuel-based resources, have prompted research into the development of sustainable, environmentally friendly, and biodegradable materials for use in a variety of high-end applications. To mitigate the environmental setbacks caused by nonbiodegradable materials, the development of biocomposites with improved mechanical performance is gradually gaining momentum. Natural fibers such as hemp, flax, and sisal have been well incorporated into biocomposite development. Nonetheless, the impact of functional moieties in their life cycle cannot be underestimated. In this review paper, a detailed discussion of the characteristics and components of biocomposites is presented. The treatment of composite materials (alkali and acetylation), as well as several manufacturing processes (hand layup, 3D printing, extrusion, etc.) and the applications of biocomposites, which are not limited to the aerospace industry, packaging, biomedicine, etc., are presented. Biocomposites with excellent durability, performance, serviceability, and reliability must be produced to expand their applications.

/pdf/biobased-polymer-composites-a-review-700ur2j2.pdf

Biobased Polymer Composites: A Review

The present study investigates the effect of cellulose nanocrystals (CNCs) aspect ratio on the shear force alignment. A molecular CNC exhibits anisotropic behavior because of its different chemical bonds in different directions, especially its different mechanical properties parallel and perpendicular to its axial direction. We used these shear-force aligned films to develop biodegradable and sustainable films in a sandwiched starch/chitosan system. According to the results from 2D-XRD on the CNC films, at lower initial CNC suspension (≈1%), the calculated Hermans order parameters was much higher for the high AR (≈ 63) tunicate CNC (TCNC) as compared to the low AR (≈ 12) wood CNC (WCNC). Compared to the TCNC's Hermans order parameter, the hybrid CNC films (HCNC) (1:1 ratio of WCNC:TCNC) showed approximately similar order parameters. WCNC shear force aligned films were chiral nematically organized and did not show any alignment. Accordingly, alignment significantly affected the TCNC and HCNC's physical and mechanical properties, such as water vapor permeability, elastic modulus, and tensile strength. This paper reports the study results on the alignment of CNCs with different ARs and the hybrid configuration under shear force and its effect on the physical and mechanical properties of the polymeric nanocomposites. 

Yuying Yan

Papers

Multilayer photonic films based on interlocked chiral-nematic cellulose nanocrystals in starch/chitosan.

Multilayer photonic films based on interlocked chiral-nematic cellulose nanocrystals in starch/chitosan

Comparison of Protein Content, Availability, and Different Properties of Plant Protein Sources with Their Application in Packaging