The trend of plastic recycling has been adopted around the world in an attempt to reduce the overloading of landfills. However, recycling only accounts for approximately 10% of all plastic production, based on the global average in 2016. Thermosets are listed among the toughest materials to be recycled and are said to be impossible to recycle in some cases. Known to have excellent strength and unconvertable shape under heat exposure, thermosets have been chosen to be practically used in various structural and outdoor applications for a long time. Thermosets have an outstanding dimensional stability due to the presence of chemically cross-linked networks. Thermosets such as epoxy and phenolic have been widely used in various applications including coatings, adhesives, composites, and electronic packaging. Composites made from natural fibres as the reinforcement and thermoset as the matrix are known as thermoset-based natural composites.

Recently several initiatives have been taken to introduce recyclable thermosets, including the use of cellulose-based materials. Assumed to be a new material, this recyclable thermoset therefore needs to be characterized. Recyclable and conventional thermosets can be use with synthetic fibres, but the potential use of thermosets has been widened to be combined not only with synthetic fibres, but also natural fibres and their hybrids. A novel group of composites had been acknowledged since the introduction of natural fibres as reinforcement in polymer matrix composites. Such materials offer a lightweight advantage with comparable strength to conventional synthetic composites. Continuous awareness of renewable green resources and eco-friendly and biodegradable materials has enforced rapid research and development activities on natural fibre composites. Several drawbacks and challenges were identified at the early stage of introducing natural fibres in polymers, such as poor fibre-polymer compatibility and high moisture absorption properties of natural fibres. More research needs to be done to improve and enhance the performance of natural fibre composites in light of these disadvantages and the limitations of natural fibres.

This Special Issue aims to present original research and review articles related to thermoset-based natural composites. An informative collection on experimental techniques, starting from the composite preparation up to the characterization of the composite, will be presented in this Issue. This Special Issue also aims to enhance reader understanding of the structure, applications, and performance of the thermoset-based natural composites.

Potential topics include but are not limited to the following:

• Preparation of natural fibres for thermoset composites (extraction, surface modification)
• Nanofiller in thermoset composites
• Analysis and damage evaluation of thermoset-based natural composites
• Morphological observation of thermoset-based natural composites
• The potential of natural fibre composites in various applications
• Recycling of thermoset-based natural composites