Globally increasing environmental awareness and the possibility of increasing price and dwindling supply of traditional petroleum-based plastics have led to a breadth of research currently addressing environmentally friendly bioplastics as an alternative solution. In this context, hemicellulose, as the second richest polysaccharide, has attracted extensive attention due to its combination of such advantages as abundance, biodegradability, and renewability. Herein, in this review, the latest research progress in development of hemicellulose film with regard to application in the field of food packaging is presented with particular emphasis on various physical and chemical modification approaches aimed at performance improvement, primarily for enhancement of mechanical, barrier properties, and hydrophobicity that are essential to food packing materials. The development highlights of hemicellulose film substrate are outlined and research prospects in the field are described.

Polylactic acid (PLA) is one of the most productive biodegradable materials. Its bio-based source makes it truly carbon neutral. However, PLA is hard to crystallize as indicated by a low crystallization rate and a low crystallinity under conventional processing conditions, which limits its wider application. One of the most effective ways to enhance the crystallization ability of PLA is to add nucleating agents. In the context of increasing global environmental awareness and the decreasing reserves of traditional petroleum-based materials, biomass nucleating agents, compared with commonly used petroleum-based nucleating agents, have received widespread attention in recent years due to their abundance, biodegradability and renewability. This paper summarizes the research progress on biomass nucleating agents for regulating the crystallization behavior of polylactic acid. Examples of biomass nucleating agents include cellulose, hemicellulose, lignin, amino acid, cyclodextrins, starch, wood flour and natural plant fiber. Such green components from biomass for PLA are believed to be a promising solution for the development of a wholly green PLA-based system or composites.

Self-healing polyurethanes (PUs) represent a new type of functional material which are highly desirable for applications such as surface protection coatings and transparent films. However, it is still challenging to obtain self-repairable PUs with good mechanical properties and excellent optical properties. Herein, in view of molecular design, a self-healing thermoplastic polyurethane (TPU) was designed with polytetramethylene ether glycol (PTMEG) as the soft segment and aliphatic isocyanate (m-xylylene diisocyanate, XDI) and aliphatic disulfide (bis(2-hydroxyethyl)disulfide, HEDS) as the hard segment. The TPU exhibited widely tunable mechanical properties, i.e., tensile stress values of 3.51–8.12 MPa with elongation at break values of 825–1320%. The cooperation of dynamic disulfide bonds and hydrogen bonding endowed the TPU elastomer with self-healing capacity and a self-healing efficiency of about 39% at a moderate temperature. Both the amorphous phase structure and XDI chemical structure contributed to a colorless, transparent and anti-yellowing TPU film with nearly 97% transparency and long-term optical stability. The tough, colorless and transparent self-healable elastomers have wide applications in optical and protective fields, including in automotive laminated glass, flexible displays, printers, and photographic equipment cleaning scrapers.