The Microstructure of GNR and the Mechanical Properties of Biobased PLA/GNR Thermoplastic Vulcanizates with Excellent Toughness

• Main Authors: Mingfeng Xia, Wenchao Lang, Yue Yang, Jihang Yu, Ningjing Wu, Qingguo Wang
• Format: Article
• Language: English
• Published: MDPI AG 2019-01-01
• Series: Materials
• Subjects: PLA; thermoplastic vulcanizates; bulk-grafting reaction; crosslinking density; super-tough; ductility
• Online Access: http://www.mdpi.com/1996-1944/12/2/294

A series of different contents of glycidyl methacrylate (GMA)-grafted natural rubber (GNR) copolymers were fabricated via green bulk melt-grafting reactions, and super-tough bio-based poly (lactic acid) (PLA)/GNR thermoplastic vulcanizates (TPVs) were achieved by in-situ dynamic vulcanization. Increasing the graft yield, gel fraction, and crosslinking density of GNR vulcanizates effectively improved the ductility of the PLA/GNR TPVs, while prolonging the dynamic vulcanization time and increasing the GMA graft yield led to a notable enhancement in the impact toughness of the PLA/GNR TPVs. PLA/30 wt % GNR TPVs exhibited a significantly increased elongation (410%) and notched impact strength (73.2 kJ/m2), which were 40 and 15 times higher than those of the PLA/30 wt % NR TPVs, respectively. The new bio-based PLA/GNR TPVs offer promise as replacements for petroleum-based polymers in the automotive, 3D printing, and packaging fields.