Interest in constructing composite materials from biosourced, recycled materials; waste resources; and their combinations is growing. Biocomposites have attracted the attention of automakers for the design of lightweight parts. Hybrid biocomposites made of petrochemical-based and bioresourced materials have led to technological advances in manufacturing. Greener biocomposites from plant-derived fiber and crop-derived plastics with higher biobased content are continuously being developed. Biodegradable composites have shown potential for major uses in sustainable packaging. Recycled plastic materials originally destined for landfills can be redirected and repurposed for blending in composite applications, thus leading to reduced dependence on virgin petro-based materials. Studies on compatibility of recycled and waste materials with other components in composite structure for improved interface and better mechanical performance pose major scientific challenges. This research holds the promise of advancing a key global sustainability goal.

The detrimental impact of single-use plastics on the environment is daily news across the globe. Single-use plastic packaging materials and other plastic waste originating from petroleum-based sources are continuously building up in landfills and leaching into the environment. Managing plastic waste remains an urgent crisis in the environment and switching to biodegradable plastics can help mitigate some of these issues. This review will summarize recent advances and opportunities to utilize polyhydroxyalkanoates (PHAs) as a biodegradable substitute in some applications where non-biodegradable and petroleum-based plastics are currently used. PHAs are a well-known family of bacteria-based biodegradable plastics and offer an approach to carbon neutrality and support a more sustainable industry. PHAs such as poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) show biodegradable behaviour in all aerobic and anaerobic environments defined by ASTM standards, and can be used to make completely compostable, and soil and marine biodegradable products – a strong positive compared to the negativity associated with the landfilling of plastics. However, PHAs are relatively expensive compared to petroleum-based alternatives. To reduce the cost, PHAs can be used in biocomposite materials, where bio-based agro-residues are incorporated, while maintaining the performance in certain applications. Organic fillers and fibres composed of cellulosic material can improve the properties of polymers, however, their effect on the marine biodegradable properties of the composite matrix remains an unexplored area. When used in biocomposites with PHAs, they improve biodegradation rates in all environments. In addition to cellulose, other bio-based fillers such as proteins (i.e. distillers dried grains with solubles) and starch have been reported to significantly improve soil and marine biodegradability rates compared to other fibres and fillers. Other components that affect biodegradability are additives (i.e. chain extenders) and compatibilizers (i.e. maleic anhydride etc.) that are added to optimize the service life properties, but are reported to inhibit the biodegradation properties by impacting the hydrophilicity of the polymer and enzyme activity. The multitude of possible combinations of polymers and fillers and fibres, and their effect on the biodegradation of PHA-based biocomposites are a largely unexplored frontier. The potential benefits of PHA-based biocomposites make a strong case for further research into this area.

Evolution of the bioplastics industry has changed directions dramatically since the early 1990s. The latest generation is moving toward durable bioplastics having high biobased content. The main objective is to replace “fossil carbon” with “renewable carbon”, a holistic strategy to mitigate climate change by minimizing the environmental impact of a product throughout its life cycle. Durable bioplastics is desired for multiuse long-term application in automotive, electronics and other industries. One necessary requirement for them is to be both tough and strong, yet the two attributes are often mutually exclusive. Does this mean a biobased and biodegradable polymer as polylactic acid (PLA) with its high strength but low toughness cannot be adopted for durable applications? Well, not exactly; this is where the concept of tailoring the properties of PLA to achieve stiffness–toughness balance along with acceptable heat resistance comes into play. In this perspective, we summarize the recent research progress in addressing the toughness vs strength and heat resistance conflict inherent in PLA. Blends having super toughness and composites based on the toughened PLA blends formulated to obtain desired material properties are covered. Morphology and crystallinity that individually contribute to toughness and heat resistance have also been elucidated.

Valorization of food waste (FW) is instrumental for reducing the environmental and economic burden of FW and transitioning to a circular economy. The FW valorization process has widely been studied to produce various end-use products and summarize them; however, their economic, environmental, and social aspects are limited. This study synthesizes some of the valorization methods used for FW management and produces value-added products for various applications, and also discusses the technological advances and their environmental, economic, and social aspects. Globally, 1.3 billion tonnes of edible food is lost or wasted each year, during which about 3.3 billion tonnes of greenhouse gas is emitted. The environmental (-347 to 2969 kg CO₂ equiv/tonne FW) and economic (-100 to $138/tonne FW) impacts of FW depend on the multiple parameters of food chains and waste management systems. Although enormous efforts are underway to reduce FW as well as valorize unavoidable FW to reduce environmental and economic loss, it seems the transdisciplinary approach/initiative would be essential to minimize FW as well as abate the environmental impacts of FW. A joint effort from stakeholders is the key to reducing FW and the efficient and effective valorization of FW to improve its sustainability. However, any initiative in reducing food waste should consider a broader sustainability check to avoid risks to investment and the environment.

The majority of materials used for short‐term and disposable packaging application are non‐biodegradable which are not satisfying the demands in environmental safety and sustainability. Biodegradable polymers are an alternative for these non‐biodegradable materials. The biodegradable polymeric materials can degrade in a reasonable time period without causing environmental problems. However, biodegradable polymers possess some limitations such as comparatively high cost, insufficient mechanical performances, and inferior thermal stability to extend their widespread application in packaging industry. To overcome these limitations, one of the most commonly used strategies is melt blending of dissimilar biodegradable polymers. Unfortunately, most of the biodegradable polymer blends exhibit insufficient performance because they are thermodynamically immiscible as well as exhibit poor compatibility between the blended components. It has been established that the compatibilization is a well‐known strategy to improve the performances of the immiscible biodegradable polymer blends by enhancing the adhesion between the phases. As a result, recent studies focus on various compatibilizers to enhance the performances of the resulting biodegradable polymer blends. This review summarizes the recent developments on a variety of biodegradable polymer blends compatibilized by melt processing with a main focus of ex situ and in situ compatibilization strategies. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45726.