Adhesion property of crosslinked epoxidized (natural rubber)/(acrylonitrile‐butadiene) rubber blend adhesives in the presence of petro resin tackifier

Abstract

Loop tack, peel strength, shear strength, and morphology of (benzoyl peroxide)‐cured epoxidized natural rubber (ENR 25)/(acrylonitrile‐butadiene) rubber (NBR) blend adhesive were investigated by using petro resin as the tackifying resin. Benzoyl peroxide loading varied from 1 to 5 parts by weight per hundred parts of resin (phr), whereas the petro resin loading was fixed at 40 phr. A SHEEN hand coater was used to coat the adhesive on the polyethylene terephthalate substrate at 30 μm and 120 μm coating thicknesses. (ENR 25)/NBR adhesive was crosslinked at 80°C for 30 min prior to the determination of adhesion strength by a Lloyd adhesion tester operating at 10–60 cm/min. Results show that maximum loop tack and peel strength occur at 2 phr of benzoyl peroxide loading, whereby optimum cohesive and adhesive strength are obtained. However, shear strength increases with increasing benzoyl peroxide concentration, an observation that is associated with the steady increase in the cohesive strength. Scanning electron microscopy micrograph shows that little adhesive remained on the substrate at 0 phr compared with 2 phr of benzoyl peroxide loading, indicating that crosslinking increases the peel strength of the adhesive. In all cases, the adhesion properties increase with coating thickness and testing rate. J.VINYL ADDIT. TECHNOL., 24:93–98, 2018. © 2015 Society of Plastics Engineers

Effect of UV-Irradiation on Fluorescence of Poly (Para-Ethoxystyrene) Films with Phthalate and Terephthalate Plasticizers

“…They reported three cases of benzene ring photo-oxidation: formation of benzyl acetophenone chromophores; acetophenone structures; and conjugated double bonds. The same observation was noticed in the irradiation of other substituted polystyrenes in solid films [25,26]. As can be seen from Figs.…”

“…In an earlier study, it has been reported that irradiation of polystyrene solid films resulted in changes in many bands in the FT IR spectra [9], and also was noticed in the irradiated pure and blended poly (fluoro styrene) isomers with phthalate and terephthalate plasticizers in solid films [24,25]. The same observation was noticed in the irradiation of poly (4-vinyl biphenyl) solid films [41].…”

“…The chemical changers during irradiation of polymer solid films were assessed by FT IR spectra. These changes in the bands are corresponding to the photodegradation and to the photo-oxidation of polymeric chains [25]. It was observed that the most demonstrated trend was the increase of the increase in the intensity of the absorption band upon irradiation of polymeric films in the range (3,750-3,200 cm -1 ).…”

“…For the photodegradation of polystyrene containing carbonyl group, it was found that the efficiency of degradation of polymeric chromophores increased with the increase in the exposure time, and showed a change in the average molecular weight as a consequence of chain dissociation. The photodegradation of halogen substituted styrene in solid films showed a degradation of polymeric chromophores and is enhanced by plasticization with phthalate and terephthalate plasticizers [25,26]. The irradiated polymers showed a yellowish discoloration caused by irradiation; this was related to the formation of chain double bonds as a result of hydrogen atom abstraction from the C-atom in  position of the phenyl group.…”