Influences of the grafting percentage of natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on properties of its vulcanizates

Abstract

The graft copolymerization of 2‐hydroxyethyl acrylate (HEA) monomer onto natural rubber (NR) latex was successful using cumene hydroperoxide and tetraethylene pentamine as redox initiators. The grafting of poly(2‐hydroxyethyl acrylate) (PHEA) on the NR particles was confirmed by Fourier transform infrared spectroscopy, 1H NMR spectroscopy and TEM. The NR‐g‐PHEA with various grafting percentages (0%, 8.7%, 14.3% and 18.7%) was compounded on a two‐roll mill with a sulfur vulcanization system. The effects of grafting percentage on the cure characteristics, dielectric properties, thermal properties and physical properties of NR‐g‐PHEA vulcanizates were investigated. It was found that increased grafting caused NR‐g‐PHEA vulcanizates to have reduced water contact angle, scorch time and cure time, while the dielectric constant and dissipation factor increased. The NR‐g‐PHEA vulcanizate with 8.7% grafting exhibited the highest delta torque (MH − ML), crosslink density, tensile strength, moduli at 100%, 200% and 300% strains, and hardness, with insignificant loss of elongation at break in comparison to the other cases. © 2018 Society of Chemical Industry

Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate

“…This is confirmed by an increase in CRI for higher degree grafting. Higher degrees of grafting were caused by crosslinking reactions via the sulfidic linkages as well as reactions of carbonyl groups between MMA molecules [43]. Figure 11 shows the influence of the weight concentration of MMA used in the graft copolymerization on torques.…”

Natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on cure characteristics and mechanical properties of silica‐filled natural rubber composites

“…The NR used was Standard Thai Rubber (STR5L) produced by the Rubber Authority of Thailand (Nakhonsrithammarat, Thailand). NR grafted poly(2‐hydroxyethyl acrylate) (NR‐g‐PHEA) used as compatibilizer was prepared and characterized as in our previous studies . Silica, Ultrasil VN3 with cetyltrimethylammonium bromide, having specific surface area 165 m 2 /g, was used.…”

“…NR‐g‐PHEA used as compatibilizer in this study was prepared and characterized as in our previous research . The formulations of the NR/silica compounds are expressed in parts per hundred of rubber in Table .…”

“…In our previous work, a novel chemically modified NR, with PHEA grafted via emulsion polymerization in latex state, was studied . There is no prior study on the use of NR‐g‐PHEA as compatibilizer for NR/silica composites.…”

Effects of octamethylcyclotetrasiloxane grafting and in situ silica particle generation on the curing and mechanical properties of a styrene butadiene rubber composite

“…8 In previous work, many studies focused on graing rubber using the vinyl monomers, such as maleic anhydride (MA), 9 vinyl alcohol (VA), 10 stearyl methacrylate, 11 methyl methacrylate (MMA), 12 glycidyl methacrylate (GMA), 13 acrylonitrile (AN), 14 styrene (St), 15 vinyltriethoxysilane 16 and so forth. The methods for the preparation of graed rubber include thermal gra copolymerization [17][18][19][20] and irradiation graing polymerization. [21][22][23] Second, the generation of the in situ silica in the rubber matrix by the sol-gel reaction of TEOS is another effective technology, and this technology has been used in various rubber forms, such as solid rubber, 24,25 rubber latex 26,27 and rubber solution.…”