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The blending of polymers is an efficient means for developing new materials in a less hazardous and more economical way compared to the synthetic route. Polymers with different properties are blended to obtain a new material with combined properties. In this study, a thermoplastic elastomer blend is prepared by melt mixing a metallocene-based polyolefin elastomer (Engage 8003, abbreviated as EN) with linear low-density polyethylene (LLDPE, abbreviated as LL) using a twin-screw extruder in various compositions. To investigate the effect of the electron beam on the properties, LL, EN and their blends are irradiated in the 50–250 kGy dose range. The samples are subjected to gel fraction, mechanical, dynamic mechanical, hardness, heat shrinkability, volume resistivity and morphological studies. The % gel fraction, hardness and heat shrinkability of a sample increase with an increase in the irradiation dose. With increasing LL content, Young's modulus and ultimate tensile strength of the blends are increased, maintaining the % elongation at break in an attractive region. LE64 (60 wt% LL and 40 wt% EN) and LE46 (40 wt% LL and 60 wt% EN) blends show optimized mechanical and dynamic mechanical properties. Irradiation further increases the tensile strength and Young's modulus of LE64 up to 150 kGy and LE46 up to 200 kGy. The volume resistivity of the LE64 blend increases tenfold and quadruples for LE46 compared to non-irradiated blends when irradiated at 200 kGy. The morphological structures of the non-irradiated and crosslinked blends support the outcome of the obtained properties nicely. [ABSTRACT FROM AUTHOR]

ABSTRACT: A series of ethylene vinyl acetate (EVA)/ethylene‐propylene diene elastomer (EPDM) blends (50/50 ratio) with four types of EVAs were prepared using brabender type batch mixer followed by compression molding. All compression‐molded samples were exposed to gamma radiation at 500, 1000, and 1500 kGy doses and were subjected to mechanical, compression set, thermal and morphological test. The % retention in tensile strength, elongation, and hardness were found higher for higher vinyl acetate (VA) containing radiation aged EVA/EPDM blends. The compression set value was decreased with increase of VA content. The thermal degradation kinetics of high VA containing irradiated blend (EVA40/EPDM) (EVA40 is 40%VA containing EVA) was found slower than those of lower VA containing blend (EVA18/EPDM). The surface morphology for EVA18/EPDM sample was transformed into more irregular one with more cracks and fragmented segments by aging at 1500 kGy dose while surface for EVA40/EPDM sample was found comparatively smooth, fine, and continuous with very few cracks and fragmented parts at similar dose. Thus, from the measured properties and morphology, it was revealed that the degree of degradation of blends kept on decreasing with increase in VA content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46216. [ABSTRACT FROM AUTHOR]

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]

ABSTRACT A series of ethylene vinyl acetate/ethylene-propylene diene elastomer (EVA/EPDM) blends with four types of EVAs with various vinyl acetate (VA) content, are prepared without and with crosslinker, trimethylol propane triacrylate (TMPTA). These are irradiated by electron beam (EB). As the VA content increases, the gel content, i.e., degree of crosslinking of EVA/EPDM blends, is increased. With increase in VA content, the modulus and tensile strength are decreased but elongation at break is increased due to increase in amorphousness. On EB irradiation, modulus and tensile strengths are increased but at the cost of elongation at break. Crystallinities of all blends are decreased with increase in VA and EB crosslinking. The thermal stability of EVA/EPDM blend is decreased with increase in VA content but increased after EB irradiation. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) show that with increase in VA content the miscibility of two polymers keeps on increasing, which even become more after EB irradiation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43468. [ABSTRACT FROM AUTHOR]

In this investigation, a gamma radiation‐induced methacrylic acid (MAA)‐grafted ethylene‐propylene‐diene elastomer (EPDM) was used as a third component (g‐EPDM) in silicone rubber (SiR)/ethylene‐propylene‐diene elastomer (EPDM) blends. These blends were electron beam (EB) crosslinked. The effect of blend composition, the presence of g‐EPDM, and EB crosslinking on the mechanical, heat shrinkability, electrical, and morphological properties of SiR/EPDM blends have been studied. To investigate the effect of grafted EPDM (g‐EPDM), 10 wt % of g‐EPDM was added to immiscible SiR/EPDM blends. Both silicone and EPDM are blended in different proportions (70:30 and 30:70) with and without g‐EPDM followed by compression molding. To improve the properties and investigate the crosslinkability of binary and ternary blends further, the SiR/EPDM blends were irradiated by electron beam at different doses (50, 100, and 150 kGy). The gel content was found to increase with EPDM content, the presence of g‐EPDM, and radiation dose. The addition of g‐EPDM led to improvement of tensile properties (tensile strength, Young's modulus, percentage elongation, and toughness), electrical properties, and shrinkability of blends. EB crosslinking further enhanced the above properties. Surface morphology (SEM) revealed that the presence of g‐EPDM and the incorporation of EB crosslinking improved the above properties of blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47787. [ABSTRACT FROM AUTHOR]