Radiation-assisted controlled grafting and reaction parameter optimization of an industrially important polyolefin elastomer (POE)

Abstract

Controlled (low degree) grafting of a polar group to a non-polar polymer or reverse is an important means to change the polarity of the base polymer, maintaining the properties of the polymer. In the present study, a polar monomer, methacrylic acid (MAA), was grafted onto three different types of "Engages" (a special type of polyolefin elastomer) in aqueous medium by gamma radiation. Grafting parameters (total dose, MAA concentration, and Mohr's salt concentration) were optimized for the desired amount of low-degree grafting (less than 15 wt%). The grafting yields were measured gravimetrically. Pure and grafted Engages were characterized by Fourier transformed infrared spectroscopy, contact angle measurement, and scanning electron microscope. Fourier transformed infrared spectroscopy spectra confirmed the successful grafting of MAA onto the Engages. For all three, the best yields were found at 3-kGy gamma radiation dose, 25-vol% MAA, and 20-mM Mohr's salt concentration. The grafting efficiencies follow a descending trend like Engage 8150 > Engage 7447 > Engage 8003. From contact angle measurement, it was seen that the hydrophilicities of all Engage surfaces were increased after grafting. Scanning electron microscope illustrated the best distribution of grafted MAA molecules to be on Engage 8150 surface followed by Engage 7447 and Engage 8003, respectively. The tensile testing results suggested that the mechanical properties of the base polymers remained almost unchanged after grafting. Thus, without detrimenting any basic properties, polyolefin elastomers can be grafted to achieve desired yield by an environmental-friendly method, gamma radiation grafting, in aqueous media.

Modified ethylene‐propylene‐diene elastomer (EPDM)‐contained silicone rubber/ethylene‐propylene‐diene elastomer (EPDM) blends: Effect of composition and electron beam crosslinking on mechanical, heat shrinkability, electrical, and morphological properties

“…The reaction of the carboxylic group with hydroxyl or hydrogen radical is much slower. Depending on several factors, the yield and reactivity of different macro‐radicals generated from MAA will be different, which will lead to various grafted EPDM with various yields and various numbers of MAA units in the branch …”

Electron beam assisted recycling of polyurethane (PU) sponge: Turning it into a superabsorbent for wastewater treatment

“…Though most classical one is to add a free radical initiator, 25 however, this work choses EB irradiation considering the advantages of high energy radiation technology. [22][23][24] Scrap PU sponge blocks are ultrasonically cleaned with ethanol and water, for 1 h to remove dirt, stains and other impurities. Then, the cleaned sponge blocks are dried in an oven at 60 C for 24 h. Direct/mutual irradiation method has been followed for attaching DMA on PU sponge by EB irradiation.…”

“…Nowadays electron beam (EB) is becoming an industrially preferable option due to better safety, higher throughput, less hectic as source replacement is not needed, minimum space requirement, easier licensing and installation procedures, and so forth. [22][23][24] Processing parameters such as total dose, DMA concentration and solvent composition are crucial for determining the extent of modification and are thus investigated and optimized. 23,24 Modified scrap PU is characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle measurement.…”

“…[22][23][24] Processing parameters such as total dose, DMA concentration and solvent composition are crucial for determining the extent of modification and are thus investigated and optimized. 23,24 Modified scrap PU is characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle measurement. Absorption capacity and contaminants removal efficiency from water is evaluated using series of organic liquids, oils, nonpolar solvent soluble dyes.…”

Radiation assisted development of linear low density polyethylene/flax fibre composites by designing interface

“…This gamma radiation-induced modification is a single-step, room temperature, easily controllable process. [16][17][18] As per our knowledge, there is no reported study on the composite of LLDPE and radiation-assisted surface modified flax fibre. Pure and modified flax fibres are incorporated into the LLDPE matrix to prepare LLDPE/flax fibre composites.…”