Studies on the modification of nitrile rubber—poly(vinyl chloride) blends. Effect of nonconventional vulcanization systems

Abstract

The effect of three selective vulcanization systems on the properties of crosslinked nitrile rubber/poly(vinyl chloride) (NBR/PVC) blends is compared with a sulfur vulcanization system. The reaction modes of activated m‐phenylene bismaleimide, p‐nitroso diphenyl amine (PNDA) as well as peroxide activated pentaerythritol triacrylate (PETA) were studied by thermal analysis and by determination of the gelling efficiency. While peroxide activated PETA and PNDA activated sulfur systems show high curing efficiency, the MBTS activated bismaleimide system yields poor gel content. Moreover, the PNDA activated systems have good fatigue resistance, improved resistance to thermal aging, and lowest glass transition temperature among the tested vulcanization systems. On the other hand, the peroxide activated PETA system shows good mechanical properties only before aging.

Melt compounded nanocomposites with semi‐interpenetrated network structure based on natural rubber, polyethylene, and carrot nanofibers

“…Since the crosslinking of NR was carried out after the compounding of NR and PE, PE molecules were blocked in the crosslinked NR phase. Thus, due to the interpenetration of PE chain molecules within crosslinked NR phase, the crosslinked blend and nanocomposite show higher phase dispersion compared to the normal blend and composite and since there is no chemical interaction between NR and PE phases, apparently only an IPN (interpenetrating polymer network) is developed and hence, the crosslinked XNR/PE material, by definition, can be referred to as a S‐IPN …”

Effect of bismaleimide reactive extrusion on the crystallinity and mechanical performance of poly(lactic acid) green composites

“…Several authors3–10 have reported an increase in the tensile strength and heat deflection temperature (HDT) of thermoplastic‐ and thermosetting‐based systems after bismaleimide modification, e.g., N,N′‐ m ‐phenylene bismaleimide; N,N′‐bismaleimide‐4,4′‐diphenylmethane; N,N′‐bismaleimide‐4,4′‐ diphenylsulphone, N′‐( o ‐phenylene)dimalemide. Bismaleimide contents between 5 and 12 wt %6, 9 were reported.…”

Foamability of Thermoplastic Vulcanizates (TPVs) with Carbon Dioxide and Nitrogen

“…Static vulcanization, used commercially since the days of Charles Goodyear (8) , involves the heating of a rubber stock (fully compounded and mixed with a cure system, usually sulfur) at a temperature of 130 to 180 °C for a specifi ed time, during which chemical crosslinks are formed between the macromolecules of the elastomer (e.g., natural rubber, butyl, EPDM etc.) (9,10) . This process transforms the rubber into a tough, elastic, durable thermoset material (11) .…”