Environmentally Benign and Sustainable Green Composites: Current Developments and Challenges

Increasing human population, environmental impacts of synthetic polymers and limited non-renewable resources have steered the development of sustainable alternatives. Synthetic polymer composites are made from two or more non-biodegradable components which make its recycling difficult leading to high disposal cost and negative environmental impact. Green composites are considered an alternative to petroleum-based polymer composites due to their lower environmental impacts. Voluminous researchers have proposed the development of biodegradable green composites from renewable sources like natural fibres, agricultural feedstocks and biopolymers to make them sustainable and environmentally friendly. Furthermore, these green composites mainly constituted of natural fibres and biopolymers have high specific strength, noteworthy processing benefits, and low relative density and biodegradable which makes them industrially applicable. Although green composites are sustainable and environmentally friendly, they still need to overcome challenges like low ductility, low dimensional stability, less long-term stability for outdoor applications and moisture absorption. Even though there is scope for research in future for green composites to completely substitute synthetic polymer composites, green composites are already being used in applications which require less mechanical resistance like packaging, gardening items, automotive panels, furniture. Green composites have come a long way in the past 10 years and are expected to generate properties comparable/superior to synthetic polymer composites in near future which will play a remarkable role in reducing usage of non-renewables and waste generation.