Hong Kong Research Institute of Textiles and Apparel

Recycling of garments is difficult due to the complexity of blended materials used during manufacturing. There is also the logistics challenge of processing these used materials in cities where there are no factories. Added to all this is the sheer size of this growing problem. Environmental sustainability is an urgent global challenge. We not only need to come up with innovative technologies but also to scale up these innovations rapidly into viable businesses. New research paradigms and new business models are all necessary to materialize technology and innovation into viable and impactful solutions. We share our story of the accelerated development of innovative and scalable solutions in recycling used apparel through a public-private partnership. Our key innovations include a resource-efficient and low-cost hydrothermal materials separation system and an automated, intelligent, and chemical-free mechanical recycling system that enables us to process used garments into high-value raw materials for new clothes as well as new business model for scaling up the garments recycling.

The shape memory behavior of PLLA (poly(l-lactide)) and chitosan/PLLA composites was studied. PLLA and chitosan were compounded to fabricate novel materials which may have biodegradability and biocompatibility. Chitosan does not significantly affect the glass and melting transition temperature of the PLLA. Both the pure PLLA and chitosan/PLLA composites showed shape memory effect arising from the viscoelastic properties of PLLA comprised of semi crystalline structures. The shape recovery ratio of the chitosan/PLLA composites decreased significantly with increasing chitosan contents due to the incompatibility between PLLA and chitosan. Phase separation structures of the composites were observed by using atomic force microscopy. To obtain good shape memory effect, the chitosan content should be below 15 wt%.