Improvement of thermo‐mechanical and dielectric properties of poly(lactic acid) and thermoplastic polyurethane blend composites using a graphene and BaTiO₃ filler

Abstract

This study focuses on the development of composite materials using thermoplastic polyurethane (TPU) and poly(lactic acid) (PLA) with fillers such as barium titanate (BaTiO3) and graphene. Suitable surface treatment of filler particles is applied to activate the fillers to enhance the compatibility between the fillers and polymer matrix. Specifically, the BaTiO3 particles are hydroxylated and treated with glycidyl methacrylate (GMA), which acts as a compatibilizer between the two matrix polymers. On the other hand, the graphene particles are hydroxylated and treated with isophorone diisocyanate (IPDI), which reacts with the TPU soft segment chains during composite fabrication. The composite samples are fabricated via melt‐blending at 190°C, followed by mini molding at the same operating temperature for subsequent analysis. The results demonstrate a three‐fold improvement in the dielectric constant of 40 wt.% BaTiO3 and graphene–TPU–PLA blends composites relative to that of the neat TPU, along with an improved tensile strength. The tensile strength improvement is attributed to the support of the TPU matrix against the low ductility of the PLA. The thermal conductivity was doubled as compared with the neat TPU–PLA matrix for the 40 wt.% BaTiO3 and graphene–TPU–PLA blends.Highlights Composites of TPU–PLA–graphene and BaTiO3 filler particles were fabricated. The melt blending technique was employed to fabricate the composite. The dielectric constant was analyzed at both constant and variable frequencies. Thermal conductivity was doubled (40 [graphene + BaTiO3])

Fabrication of a packaging film based on PLA blends: The evolution of physical, mechanical, and rheological properties

“…21 Meanwhile, blending is a great strategy to improve as well as tune the physical and mechanical properties of a polymer. 22,23 It has been shown that the flexibility and thermal stability of PLA can be ameliorated through blending, but selecting a suitable polymer as the second component of the blend is very important. 24,25 Poly (ethylene oxide) (PEO) is one of the most promising polymers to be combined with PLA due to its good flexibility and thermal stability.…”

Enhanced dielectric properties and energy storage performances by selectively distributed BaTiO3 in polyvinylidene fluoride/low‐density polyethylene blends

“…Su et al 7 boosted the dielectric constant of high‐density polyethylene (HDPE) from 2 to 30 with 50 vol% BaTiO 3 particles. BaTiO 3 (barium titanate, BT) with high dielectric constant is widely applied as a kind of typical dielectric fillers 8,9 . High loading levels of BT are frequently adopted to obtain the composites with high dielectric constant, which usually result in the filler agglomeration and the impaired dielectric properties such as lower breakdown strength and higher dielectric loss 10,11 .…”