Julia L. SHAMSHINA1, Noureddine ABIDI1, Robin D. ROGERS2
1Texas Tech University, Lubbock, United States
2525 Solutions, Inc., Tuscaloosa, United States
A large amount of biomass wastes such as discounted cotton unsuitable for the textile industry (~ 30% of the total production), crop wastes, crustacean biomass, etc. represent the current wasteful system of resource use. At the same time, biopolymers, such as cellulose and chitin, are the most suitable raw materials for bioplastics production. These biopolymers represent the abundant resource (the production of cellulose and chitin is ~5 x 1011 metric tons/year and ~1011 metric tons/year, respectively), and are included in the Environmentally Degradable Plastics list (EDP). These untapped resources could be used to produce high-value products if technologies for conversion of waste into products are developed.
Contrarily to plastics, which are to a large extent processed by injection-, extrusion-, blow- or rotational-molding, biorenewable polymers cannot be melt-processed and hence are not directly replaceable in melt processing technologies. Instead, they have to be solubilized to prepare biopolymeric materials. Last two decades’ developments include solution processing of biopolymers in ionic liquids (ILs) as one of the most promising strategies for the biopolymer’s handling. Functional low-value (e.g., packaging), medium value (e.g., catalysts), and high-value (e.g., drug carriers, tissue engineering scaffolds, biomimetics) products are now accessible.
Even though there have been quite noticeable efforts toward the introduction of biopolymers in general – and their processing using ILs in particular – the widespread commercial production of biopolymer-based products has not really taken off. This is due to a significant capital investment needed to implement a totally new process on a commercial scale, the cost of IL itself, which, according to sensitivity analysis, represented a major cost driver, and lack of a large and consistent supply of high molecular weight biopolymers such as chitin. It is timely to work together with industry partners to develop solutions for preparation of biodegradable bioplastic packaging materials while addressing the following challenges: A low technologies readiness level (TRL); Differences in technical performance expectations (e.g., moisture sensitivity, structural integrity, elasticity, guaranteed minimum shelf life); Requirements for strict regulations about biodegradable plastic disposal; Need for reorganization of the internal and external supply chains for bioplastic producers; Implications of a socio-technical transition; and Availability and scalability of raw materials supply.
The presentation will discuss multiple ways to transform biopolymers into fibers, membranes, microbeads, nanomats, etc. through spin-, dip-, or spray-coating, casting, molding, 3D printing, jet wet- and dry-spinning, and electrospinning. We will also elaborate on challenges and prospective of preparation of biopolymeric materials from chitin and cotton cellulose raw sources, using ILs as solvents – what today appears to be the competing interests of society, the environment, and economic prosperity.