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ABSTRACT To observe the effect of ENGAGE (a poly-olefin elastomer) on compatibilization of industrially important incompatible blend, high-density polyethylene (HDPE)/ethylene-propylene diene elastomer (EPDM), 15 wt % ENGAGE is incorporated into the system and the latter is found satisfactorily efficient as compatibilizer for the above system. To improve some industrially pertinent properties another strategies are also followed in addition, incorporation of magnesium hydroxide [Mg(OH)2] and electron beam (EB) crosslinking into the system. The gel content was found to increase with radiation dose, EPDM content and Mg(OH)2 dispersion. ENGAGE interestingly increases the gel content that is, promotes crosslinking. It is unique that filler dispersion and crosslinked network formation maintain the compatibility of the ternary system, which is confirmed by X-ray diffraction, differential scanning calorimetry, mechanical properties, and scanning electron microscope. The compatibilization, Mg(OH)2 dispersion, and EB crosslinking improve the mechanical, thermo mechanical, flame retardant properties, and phase morphology considerably. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44922. [ABSTRACT FROM AUTHOR]

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. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]