• Advances in materials Research
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• v.3 no.3
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• pp.175-183
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• 2014

Natural rubber bound phenolic antioxidant, 2,6-di-tert-butyl-4-vinylphenol (2,6-DBVP), was prepared from natural rubber and 2,6-DBVP in both solution and melt state. The 2,6-DBVP had been synthesized from 3,5-di-tert-butyl-4-hydroxybenzaldehyde and methyltriphenylphosphonium iodide ($MePPh_3I$) by Wittig reaction ($0^{\circ}C$ for 2 hrs, $N_2$ atmosphere). The conditions for preparation of natural rubber bound 2,6-DBVP (NR-DBVP) were optimized for both solution state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 2 hrs) and for melt state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 10 mins, with rotor speed of 60 rpm). A thermoplastic vulcanizate was obtained using a compatibilizer, polypropylene modified with phenolic resin (PhHRJ-PP), in a closed mixer ($180^{\circ}C$ for 3 mins, rotor speed 60 rpm). The antioxidant properties of vulcanized NR-DBVP, using phenolic as the vulcanization system, were similar to NR with the conventional antioxidant BHT. In addition, the antioxidant, water leaching property of the thermoplastic vulcanizate of NR-DBVP/PP were good in comparison to a NR blend with BHT; the morphologies of these thermoplastic vulcanizates were similar.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1809-1813
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• 2003

Monomeric antioxidant 1 was prepared by the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with N-[4-(chlorocarbonyl)phenyl]maleimide in the presence of imidazole. Monomeric antioxidant 2, bearing carbamate group, was synthesized from the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and azidomaleimide. Antioxidant 3 was prepared by the reaction of N-(4-hydroxyphenyl)maleimide and 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionic chloride in the presence of triethylamine. These reactive antioxidants were grafted onto polypropylene (PP) by melt-processing with free radical initiators in a mini-max moulder. From the infrared spectra of the grafted PP, it was found that the monomeric antioxidants were grafted onto PP. IR spectroscopic methods were used for the quantitative determination of the extent of grafting of monomeric antioxidant. To optimize the reaction conditions, the influences of the concentration of DCP, monomeric antioxidant, reaction time and temperature on the extent of grafting were studied.