Reinforcement of EPDM by in situ prepared zinc dimethacrylate

Abstract

ABSTRACT:The mechanical properties and crosslink density of peroxide-cured ethylene-propylene-diene rubber (EPDM) reinforced with zinc dimethacrylate (ZDMA) were studied. ZDMA was in situ prepared in EPDM matrix through the neutralization reaction of zinc oxide (ZnO) and methacrylate acid (MAA). The effect of ZnO/MAA amount and molar ratio of ZnO/MAA on the properties of the EPDM vulcanizate were investigated in detail. The experimental results showed that EPDM can be greatly reinforced by ZDMA. The excess amount of ZnO considerably increases the tensile strength of the EPDM vulcanizate to reach as high as 37 MPa, whereas its elongation at break keeps over 350%. The process of in situ formation of ZDMA in the EPDM compound was verified by WAXD. Such vulcanizate contains both covalent crosslinks and ionic crosslinks. Crosslink density was determined by an equilibrium swelling method. Dependence of crosslink density on the amount and molar ratio of ZnO/MAA was studied and the extraordinary high tensile strength of the EPDM/ZDMA vulcanizate was related to ionic crosslink density.

Reinforcement of nitrile rubber by in situ formed zinc disorbate

“…Since highly filled zinc dimethacrylate (ZDMA) reinforced hydrogenated nitrile rubber (HNBR) with high tensile and excellent abrasion resistance was developed by Zeon Chemicals, reactive metal carboxylates have been tried as novel rubber reinforcements for their good dispersion properties and reinforcing effect [7][8][9][10][11][12][13][14][15][16][17][18]. Zhang and coworkers [11][12][13][14] investigated the in situ formation of ZDMA and magnesium dimethacrylate (MDMA) by the reaction of zinc oxide (ZnO), magnesium oxide (MgO) with methacrylic acid (MAA), and discussed the reinforcing effect of the resultants on the rubbers. Lu et al [16] investigated the morphologies of ZDMA particles in various elastomers before and after vulcanization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).…”

Structure, morphology, and mechanical properties of polysiloxane elastomer composites prepared by in situ polymerization of zinc dimethacrylate

“…The HRTEM images given in Figure 8b-d clearly show that there are significant amounts of nano-dispersed structures (the darker phase) forming in the composites. These nano-dispersed structures, which are about 5-10 nm in diameter, represent poly-ZDMA aggregates or poly-ZDMA ionic clusters [23,[28][29][30][31][32] produced by the in situ polymerization of ZDMA during the peroxide curing. The TEM observations indicate that uniform nanolevel dispersion can be obtained via the in situ reaction method even though the original dispersion of ZDMA is poor.…”

“…Additionally, it can be seen that the elongation at break (over 350%) is still high even when the amount of DBPMH is as high as 6 phr. It is a characteristic property of metal salts of unsaturated carboxylic acids that they impart high strength and hardness, while allowing the rubber to retain a high elongation at break [29]. The effect of amount of ZDMA on the mechanical properties of VMQ/ZDMA composites was investigated next.…”

“…In rubber/ZDMA composites, there are not only covalent crosslinks between the rubber chains but also ionic crosslinks mainly formed by the grafted poly-ZDMA, as shown in Figure 12. Because the ionic crosslinks have been known [22,29,30] to play an important role on the mechanical properties of rubber/ZDMA composites, it is significant and necessary to investigate the crosslink structure of the VMQ/ZDMA composites. Figure 13 shows the FTIR spectra of VMQ/ZDMA composites before and after acidolysis.…”

“…In the 'in situ polymerization' method, reactive monomers are polymerized to generate reinforcing particles. Among the reactive monomers, metal salts of unsaturated carboxylic acids are the typical monomers widely used to improve the properties of elastomers [18][19][20][21][22][23][24][26][27][28][29][30][31][32]. Wen et al [21] synthesized particles of acrylato(1,10-phenanthroline)bis (2-thenoytrifluoroacetonato) samarium [Sm(TTA)2-(AA)(Phen)], which combined the good fluorescence property of Sm(TTA)3(Phen) and the reactivity of acrylic acid with radicals, and used the particles to prepared HNBR/Sm(TTA)2-(AA)(Phen) composites.…”