Abstract Polylactic acid (PLA) and poly(butylene adipate- co -terephthalate) (PBAT) were blended in a twin-screw extruder with a compatibilizer of PLA grafted using glycidyl methacrylate (PLA- g -GMA), providing PLA- g -GMA/PLA/PBAT composites. The chemical structures of the composites were determined using Fourier-transform infrared spectroscopy (FTIR). The effects of the PLA- g -GMA amount on the thermal properties, rheological performance, and mechanical behavior of the composites were studied through differential scanning calorimetry (DSC) using an advanced rheometer and material testing machine. The results revealed that the reaction between the PLA/PBAT and epoxy groups within the PLA- g -GMA promotes an entanglement between molecular chains, which increases the glass transition temperature T g , cold crystallization temperature T c , and melting temperature T m of the samples. Moreover, the PLA- g -GMA/PLA/PBAT composites show higher tensile and notch impact strengths than PLA/PBAT.
Gaoyuan Ye,Tongfei Gu,Boyuan Chen,Hongjie Bi,Yingcheng Hu
To improve the toughness of polylactic acid (PLA), in this research, a tough polymer polycaprolactone (PCL) was combined with PLA to prepare blends, and a compatibilizer of glycidyl methacrylate grafted PLA (PLA-g-GMA) was produced to enhance the compatibility of PLA/PCL blend. Compared with PLA/PCL blend, the compatibilized blend exhibited a lower melting temperature and greater thermal stability. The tensile test indicates that the addition of compatibilizer greatly improved the toughness of the PLA/PCL blend. Particularly, the elongation at break of PLA/PCL blend with 6 wt% PLA-g-GMA increased to 370% and reached about 66 times of neat PLA. In addition, compatibilized blends have good shape memory performance. The research provides a simple and feasible method to overcome the brittleness of PLA, supplying a new strategy to modify PLA.
The applicability of bamboo flour (BF) blended with polylactic acid (PLA) to improve the properties of PLA for widespread use as an environmentally friendly, biodegradable polymer is limited by the poor compatibility of these materials. Therefore, as a potential compatibilizer for PLA/BF composites, PLA-g-glycidyl methacrylate (GMA) was synthesized by grafting GMA onto PLA using benzoyl peroxide and tert-butyl peroxy benzoate as initiators. GMA grafting onto PLA was confirmed by infrared testing and elemental analysis . Then, PLA/BF biocomposites were prepared by blending PLA (85 wt%) and BF (15 wt%) with different concentrations of PLA-g-GMA. The phase morphology, thermal stability and mechanical properties of the composites prepared with PLA-g-GMA were improved over those of PLA/BF composites without compatibilizer, as characterized by scanning electron microscopy, thermogravimetric analysis and using a universal materials tester, respectively. Specifically, the thermal decomposition temperature , tensile strength and tensile modulus of PLA/BF biocomposites prepared with 15 hpr PLA-g-GMA were increased.
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