Microporous membrane fabricated by AMS‐GMA‐TPE terpolymer grafted polypropylene prepared via extrusion

Abstract

Terpolymer poly(α‐methylstyrene‐co‐glycidyl methacrylate‐co‐4‐acryloyl tetraphenylethylene) (PAGT) was synthesized by radical copolymerization using α‐methylstyrene, glycidyl methacrylate, and trace fluorescent monomer 4‐acryloyl tetraphenylethylene. Thermal decomposition of α‐methylstyrene constitutional units in copolymer chains is known to produce macromolecular radicals at temperatures exceeding 90 °C, which may be melt‐grafted to polypropylene (PP) without other initiators by means of extrusion. In this study, the PP‐g‐PAGT microporous material was prepared by casting and stretching. The structure and properties of the PAGT were characterized by Fourier transform infrared spectroscopy, 1H‐nuclear magnetic resonance, and thermogravimetic analysis. The grafting degree and rheological properties proved that the PAGT chains were successfully grafted onto the PP. The uniformity of the PAGT in the PP‐g‐PAGT was observed using a spectrofluorophotometer. The polarity of the cast membrane was characterized by the water contact angle. The results showed that the PAGT evenly grafted onto the PP, and the polarity and hydrophilicity of the cast membranes were improved. The microporous structure of the separator was observed via scanning electron microscopy. Testing of the performance of the lithium battery showed that the impedance decreased and the ionic conductivity increased with the introduction of PAGT onto PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46020.

Preparation and characterization of melt‐stretched polypropylene–polypropylene‐g‐poly(α‐methyl styrene‐co‐glycidyl methacrylate‐co‐γ‐methacryloxypropyl trimethoxy silane)–silicon dioxide compound microporous membranes

“…The water contact angle was determined with a contact angle apparatus (Beijing Hake Experiment Instrument Factory) …”

“…The precursor films of PP–SiO 2 and PP–PP‐ g ‐PAGK–SiO 2 were prepared by cast extrusion, and then, they were annealed at 145°C for 30 min in a hot oven. The annealed films were first stretched to 15% at room temperature, then stretched to 100% at 145°C, and gave birth to the microporous membranes …”

“…The surface morphology was observed with a field emission scanning electron microscope (SUPRA55, Zeiss, Germany) . The surface porosity ( P S ) and bridge length ( l b ) of each sample was obtained via analysis of the corresponding images with an image processing software called Image‐Pro Plus …”

“…The AMS units were supposed to be weak and responsible for the thermal decomposition. When this special copolymer was added to a PP substrate at its melting temperature, the copolymer acted as a macroinitiator and made the AMS–GMA chains graft onto PP chains without extra monomers or initiators . Keeping this in mind, we designed and synthesized the copolymer PAGK via the copolymerization of AMS and the functional monomers GMA and γ‐methacryloxypropyl trimethoxy silane (KH570) and later grafted PAGK onto PP chains by melt blending.…”

Preparation of 4A zeolite coated polypropylene membrane for lithium‐ion batteries separator

“…In this regard, the battery separator's high wettability in nonaqueous electrolytes is extremely important. 10,11 There are several ways to overcome these limitations of polyolefin membrane separators; for instance, their surface modification by chemical grafting, [17][18][19] E-beam treatment, 20 or plasma treatments. 21,22 Another modification method of the polyolefin separators is to coat them with inorganic and/or organic particles.…”