Highly Tough and Thermally Stable Polylactide Blends Compatibilized with Glycidyl Methacrylate‐Grafted Polypropylene

Abstract

To attain eco‐friendly and sustainable polylactide (PLA) materials possessing highly enhanced toughness, thermal stability, and processability without significant loss in elastic modulus, for the first time, PLA‐dominant blends with 1–30 wt% glycidyl methacrylate‐grafted polypropylene (PPGMA) loadings are fabricated via an efficient masterbatch melt‐compounding process. For the purpose, PPGMA is fabricated via in situ grafting reaction of PP with GMA and styrene. The scanning electron microscope images reveal that PLA/PPGMA blends do not show recognizable phase‐separated domains, unlike immiscible PLA/PP blends. The Fourier‐transform infrared spectroscopic and melt‐rheological analyses support the presence of specific interactions between PLA and PPGMA as well as the compatibilizing effect of PPGMA‐g‐PLA formed during the melt‐compounding. The thermal analyses demonstrate that PPGMA component accelerates the crystallization of PLA in the blends and that the thermal decomposition temperatures of PLA/PPGMA blends are higher than those of neat PLA and PPGMA components. The dynamic mechanical analysis shows that a maximum storage modulus is attained for PLA‐dominant blend with 30 wt% PPGMA. Noticeably, the impact strength (≈305.6 J m−1) of PLA‐dominant blend with only 5 wt% PPGMA loading is almost three times higher than that (≈111.6 J m−1) of neat PLA and it is very comparable to the value (≈316.9 J m−1) of neat PP.

Influences of carbon nanotube on structures and properties of compatibilized polylactide/polypropylene blend-based ternary nanocomposites

“…operating at a screw speed of 50 rpm and a temperature profile of 175-195°C. 19,39 Before melt-compounding, 100 g powdery PP was pre-mixed with 10 wt% GMA, 10 wt% styrene, and 0.2 wt% DCP. For purification, the melt-compounded product was dissolved in xylene at 120°C and precipitated into acetone to remove unreacted residual components.…”

“…11 Accordingly, lots of research and development has been carried out to enhance the processability and properties of PLA materials via stereo-complexation, [12][13][14] copolymerization, 15,16 and blending. [17][18][19] Mixing two or more polymers is considered a convenient, effective, and inexpensive processing approach to manufacturing polymer materials with balanced properties for a particular end-use. 20 It is also speculated that composites based on a polymer blend matrix and a reinforcing filler could be a new type of high-performance composite materials that combine the advantages and benefits of polymer blends and composites.…”

“…We recently investigated the microstructure and properties of PLA-dominant compatible blends with glycidyl methacrylate-grafted polypropylene (PGMA) prepared by reactive melt-compounding. 19 It was revealed that PLA/PGMA blends, unlike immiscible PLA/PP blends, do not have a phase-separated structure due to the specific interaction between PLA and PGMA as well as the compatibilizing effect of PGMA-g-PLA that occurs during the melt-compounding. PLA/PGMA blends also feature noticeable improvements in toughness, thermal stability, and melt-processability without significant deterioration of mechanical modulus.…”

Sustainable and high‐performance composites based on glycidyl methacrylate‐grafted poly(lactic acid) and cellulose nanofibrils

“…Many chemical and physical treatments of matrix and fiber surfaces have been adopted to improve the interfacial strength between natural fibers and the PLA matrix 19 . Glycidyl methacrylate (GMA), a well‐known bifunctional monomer with epoxy and vinyl groups, is widely used as a reactive compatibilizing agent by grafting to olefin‐based polymers like PE and PP 19–24 . It is thus considered that the epoxy/carboxyl groups of GMA‐grafted PLA (PLA‐g‐GMA) can react and/or interact with the hydroxyl group on the surface of CNFs, resulting in improving the thermal stability and mechanical performance of PLA.…”

“…In addition, typical vibrational bands are listed in Table1. In the case of neat PLA, typical C-H stretching (ν C-H ), C=O stretching (ν C=O ), CH 3 bending (δ CH3 ), and C-O-C stretching (ν C-O-C ) vibrational bands were observed at $2993, $1748, $1452, and 1180-1081 cm À1 , respectively 23. The FT-IR spectrum of GMA displays characteristic vibrational bands of C-H stretching (ν C-H ), C=O stretching (ν C=O ), C=C stretching (ν C=C ), CH 3 bending (δ CH3 ), and epoxy C-O-C stretching (ν C-O-C,epoxy ) at $2983, $1716, $1637, $1453, and $ 911 cm À1 , respectively.…”