Synthesis, characterization, and evaluation of natural rubber‐graft‐N‐(4‐aminodiphenyl methane) acrylamide as an antioxidant

Abstract

ABSTRACT:The synthesis of N-(4-aminodiphenylmethane) acrylamide (ADPMA) was performed through the reaction of 4,4Ј-diaminodiphenyl methane and acryloyl chloride in the presence of triethyl amine. The grafting of AD-PMA onto natural rubber was executed with UV radiation. Benzoyl peroxide was used to initiate the free-radical grafting copolymerization. Natural rubber-graft-N-(4-aminodiphenyl methane) acrylamide (NR-g-ADPMA) was characterized with an IR technique. We studied the effect of aging on the mechanical properties and the swelling and extraction phenomena for acrylonitrile-butadiene copolymer (NBR) vulcanizates, which contained the prepared NR-g-ADPMA and a commercial antioxidant, N-isopropyl-NЈ-phenyl-pphenylenediamine. The prepared antioxidant enhanced both the mechanical properties of the NBR vulcanizates and the permanence of the ingredients in these vulcanizates.

Mechanism and Kinetics

“…Huang and Sundberg confi rmed that in the grafting of styrene, benzyl methacrylate, and benzyl acrylate onto polybutadiene, the degree of grafting extrapolated to zero concentration was consistent with Equation (22) and not (23) when an initiator that gave carbon -centered radicals (AIBN) was used [32] , but that Equation (23) applied for styrene and benzyl methacrylate when oxygen -centered radicals derived from benzoyl peroxide (BPO), and therefore more active in abstraction, were employed [33] . Zhou, Huang, and Liu have derived analytical expressions for the rate of polymerization in radical grafting systems where grafting is primarily by radical combination [34] or by addition across double bonds in the backbone [35] .…”

“…Typical values of activation energies of abstraction relevant to grafting and crosslinking are of the order 20 -30 kJmol − 1 [22] . The addition to a double bond in the polymer is a common means for a small radical to generate a reactive center [23] . Common polymers based on a diene monomer, such as polyisoprene and polybutadiene, have both double bonds in the backbone and pendant double bonds to which addition may take place.…”

Amelioration of acrylonitrile–butadiene copolymer properties using natural rubber graft p‐aminophenol

“…With increasing aging time, different types of antioxidants played an important role to decrease the rate of crosslinks' cleavage within the NBR vulcanizates. 5 Figures 6 and 7 indicate that after the NBR vulcanizates were exposed to aging for 14 days, the prepared NR-g-pAP improves the mechanical properties of NBR vulcanizates more than the commercial antioxidants IPPD and 6PPD, respectively. Because the rubber part of the grafted antioxidant gets attached to nitrile rubber during sulfur vulcanization and the antioxidant becomes nonvolatile and nonextractable, 11 the commercial antioxidants IPPD and 6PPD have high thermal sensitivity.…”

“…The product was dried in an oven at 408C to constant weight within 24 h. The percent graft (G%) was taken as the ratio of the graft yield to the NR multiplied by 100. 5,6 Degree of grafting ðG%Þ ¼ ðW g =ðW NR ÞÞ Â 100 where, W NR is the weight of NR and W g is the weight of graft yield. The degree of grafting was calculated as the ratio of the amount of the graft copolymer to the amount of the rubber.…”

Synthesis and Thermo-Oxidative Aging Resistance of Hydroxyl Terminated Polybutadiene Bound 2,2-Thiobis(4-methyl-6-tert-butylphenol)

“…Due to the simple preparation technology and the high antioxidant properties, polymer bound antioxidant is one of the best ways to protect unsaturated polymer, which has attracted more and more attention from polymer scientists. El-Wakil et al studied the grafting of N-(4-aminodiphenylmethane) acrylamide, 1,2-phenylenediamine, 1,5-diaminonaphthalene and p-aminophenol onto natural rubber, etc., and the results showed that the prepared antioxidant could enhance the mechanical properties of the vulcanizates, oxidative resistance, and the permanence of the ingredients in these vulcanizates [22][23][24][25] .…”