Surface modification of polypropylene waste by the radiation grafting of styrene and upcycling into a cation‐exchange resin

Abstract

In this study, we radiation‐grafted polypropylene waste (PPw) powder obtained from the accelerated aging of pristine polypropylene with styrene (St) using γ rays from a Co‐60 source at dose rate of 4.78 kGy/h. The influence of the variation of the γ absorbed dose, solvent types, and monomer concentration on the grafting yield was investigated. Solution grafting in methanol resulted in a higher grafting yield of 162.6% at 30 kGy in contrast to the 69.5% obtained in the absence of solvent. Grafting was found to be enhanced with the increased dilution of St with methanol. The grafted St units were incorporated with sulfonic (SO3H) groups by a sulfonation reaction with sulfuric acid. Fourier transform infrared spectroscopy, X‐ray diffraction spectrometry, scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, and thermogravimetric analysis were used to characterize the grafted and sulfonated products. Sulfonation of 162.6% grafted PPw powder exhibited a maximum ion‐exchange capacity (IEC) of 3.56 mequiv/g. The utilization of PPw and its conversion into sulfonated PPw with comparable IECs is a new addition to already existing radiation grafting systems. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47145.

Composite Proton-Conducting Membrane with Enhanced Phosphoric Acid Doping of Basic Films Radiochemically Grafted with Binary Vinyl Heterocyclic Monomer Mixtures

“…This behavior is ascribed to the increase in the viscosity in the grafting zone caused by the partial homopolymerization which hampered the monomer diffusion and reduced its availability in the grafting sites leading to lesser chain propagation. A similar trend was reported for RIGC of styrene onto PP films [ 42 ].…”

Synthesis, Characterization, and Adsorptive Characteristics of Radiation-Grafted Glycidyl Methacrylate Bamboo Fiber Composites

“…Grafting of “GMA” onto “VMBF” caused an increase in the peak intensity at 14–17°, which supports the grafting of GMA on VMBF . An increase in the amorphous phase after sulfonation of VMBF- g -PGMA was observed by a decrease in the peak height in comparison to that of VMBF due to the incorporation of amorphous organic groups (SO 3 H) and also an increase in the interchain distances …”

Strategic Approach Towards Plastic Waste Valorization: Challenges and Promising Chemical Upcycling Possibilities

“…[47] Radiation-grafting is an eco-friendly method that can be used to graft different monomers onto the polymer chain to modify the properties for specific end-uses. [79,80] In one such experiment, acrylic acid, vinyl acetate, and 4-vinyl pyridine were grafted to waste PE and waste rubber blends using gamma radiation. [81] These modified grafted materials can be used for metal and dye adsorption from waste water.…”

“…In one such experiment, styrene monomers were grafted onto model waste PP at room temperature using gamma rays, followed by a Soxhlet extraction to separate styrene homopolymers from the grafted product (Scheme 2g,h). [79] The grafted PP was then sulfonated using sulfuric acid to be used as a cation-exchange product for wastewater treatment. In another study, acrylonitrile was grafted onto the PP chain by gamma radiation (Scheme 2i,j).…”