Sustainable Application of Biopolymer
The widespread use of materials produced from petrochemical substrates, such as plastics, can exert an adverse impact on the environment, especially on creatures living therein, including fish and turtles in the sea, as well as the birds inhabiting the vicinity that may die from mistaking plastics for food. It is more concerning that these plastic components are highly likely to be returned to humans via the food chain. Therefore, for applications in either general-purpose industry or daily life, it is desirable to find a suitable green and environment-friendly alternative material with identical functionalities of plastics. The biopolymer material, hydroxypropyl methylcellulose (HPMC), extracted from high-purity tree pulp, exhibits excellent properties, such as good film formability, flexibility, grease obstruction, and gas penetrability as well as chemical stability. Therefore, it is worthwhile to evaluate the use of HPMC as an alternative material for fabricating functional thin films that are being produced from petrochemical substrates. In this study, using the SWOT (strengths, weaknesses, opportunities, threats) analysis, we analyze the application potential of HPMC-based multipurpose composite functional thin films. First, we evaluate the biocompatibility of HPMC films and then introduce functional thin film properties such as self-maintenance, corrosion resistance, anti-wear, and the tribology-enhancing mechanism of nanoparticles. Further, the paper presents the following potential directions for biopolymer applications: (1) corrosion-resistant thin films with tribological properties and (2) edible thin films with tribological properties. The objective is to reduce abrasion wear and lower the friction coefficient to enhance applicability and provide a composite functional thin film material that is corrosion-resistant and edible. In the future, it can be expected that customized and substantial application can be achieved by proposing varied enhancement factors according to various application scenarios, thus realizing the objective of substituting for petrochemical materials and the sustainable utilization of materials.