Efficient approach to produce functional polypropylene via solvent assisted solid-phase free radical grafting of multi-monomers

Abstract

Herein an efficient approach to produce functional polypropylene via solvent assisted solid-phase grafting process is reported, in which acrylic acid, methyl methacrylate and maleic anhydride are used as multi-monomers, 2,2′-azobis(2-methylpropionitrile) as initiator and ether as swelling solvent and carrier. The effects of various factors such as the swelling solvent species and dosage, swelling time and temperature, monomer and initiator concentrations, reaction time and temperature, nitrogen flow rate and the stirring speed on the grafting percentage and grafting efficiency were investigated. To verify the polar species was grafted onto polypropylene, the resulted polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, water contact angle measurement, tensile strength and melt flow rate measurement. All the results showed that using the ether assisted solid-phase free radical grafting process is an efficient and versatile approach to produce functional polypropylene.

Emulsion Polymerization of PMMA onto Natural Rubber

“…This reflected that the NR-PMMA copolymers could encounter chain scission during the modification process. The active radicals generated from the initiator not only initiate the grafting polymerization of the MMA onto the backbones of NR to form an NR-PMMA copolymer, but it could also deteriorate part of the samples as the side reaction …”

“…The active radicals generated from the initiator not only initiate the grafting polymerization of the MMA onto the backbones of NR to form an NR-PMMA copolymer, but it could also deteriorate part of the samples as the side reaction. 31 The shoulder peaks that can be noticed from the NR-PMMA copolymers were attributed to the heterogeneous modification of NR. The GPC results changed from unimodal to bimodal, resulting from the different side chain lengths copolymerized onto the NR-PMMA polymer.…”

Advance Analysis of the Obtained Recycled Materials from Used Disposable Surgical Masks

“…The XRD spectra for sample rEL showcases additive contributions from the components of the ear loop pieces; the peak at 22.7° can be attributed to the (002) crystallographic plane of PA6 [62], while the sharp peak at 26.5° corresponds to the (100) The wide-angle X-Ray Diffraction spectra of the prepared recycled materials are presented in Figure 13, including analysis of the peak positions, their intensity and the appearance of the background hump can assist in identifying the phases contained within the samples, their concentration and organization, as well as the extent of the amorphous phase, respectively. The diffractogram for the sample was produced from the main component of the facemask, namely the nonwoven/melt-blown three-layer structure (sample r3L), which exhibited the peaks characteristic of the α-monoclinic PP, with slight shifts: 16.5 , while the peaks at the 14.7 • and 21.9 • angles refer to a mesomorphic phase [60,61]. Additionally, the occurrence of a peak at 15.9 • is assigned to the β-hexagonal structure of PP, resulting in superimposed spectra due to the appearances of several phases.…”