Role of plasticizers in bioplastics

Abstract

Currently, a variety of petroleum based plastic materials are dominating the packaging industries owing to their durability, versatility, light-weight and most importantly their cost-effectiveness. This trend is being overcome by the growing concern towards environmental pollution caused by the production as well as the disposal of these materials and the presence of toxic substances that could migrate from the packaging material to the product causing potential risk to human health while using the product. Biopolymers, is a promising green alternative to synthetic, non-degradable polymers. These natural polymers (polysaccharides, proteins and lipids) are much more suitable components for food as well as non-food packaging applications due to their qualities of renew-ability, degradability and edibility. However, poor water vapour barrier properties of carbohydrates (polysaccharides) and proteins, and low elasticity of lipids are the main limitations for their use as commercial packaging materials. In this regard plasticizers provide the necessary workability to biopolymers. This review gives a brief insight into their plasticization effects, types, properties along with their effect and recent applications on bio-based materials, with special reference to a new class of plasticizers, Ionic liquids.

Starch Films Plasticized by Imidazolium-Based Ionic Liquids: Effect of Mono- and Dicationic Structures and Different Anions

“…However, small molecules are likely to diffuse out from polymeric materials after a short time, causing changes in the material properties. 18 Ionic liquids (ILs) have attracted much interest in the past few years in the academy and industry due to their enormous potential as substitutes for traditional plasticizers. Ionic liquids are salts in liquid state below 100 °C.…”

“…Polyols, such as glycerol and sorbitol, , or other compounds including urea and citric acid, are the most studied and used plasticizers. However, small molecules are likely to diffuse out from polymeric materials after a short time, causing changes in the material properties …”

Mechanical Properties of Biocomposite with Various Composition of CaCO3 and Starch

“…Cassava starch is a natural polymer. For plasticized purposes, we can add glycerol [6], even with low mechanical properties and hydrophilic [7]. Citric acid-epoxidized soybean oil oligomers (CESO) were prepared and utilized to improve the properties of corn starch-based bioplastics [8].…”

High-Intensity, Low-Frequency Ultrasound Treatment as Sustainable Strategy for Innovative Biomaterials with Antioxidant Activity from Tomatoes, Hemp, and Hops By-Products

“…Plasticizer can be internal or external. External plasticizers are not bound to the polymers present in a bioplastic and as such can easily be lost form the bioplastic 53 . Oils can sometimes be used as external polymers, but they will often separate from the rest of the bioplastic structure given time.…”

“…They will often bind to the polymer becoming an integral part of the final 3D structure. They are often bulky compounds which prevents the polymer chains from compacting too closely and providing better ability of molecular movement to the long polymeric chains 53 .…”