ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReductions of activated carbonyl compounds with chiral-bridged 1,4-dihydropyridines. An investigation scope and structural effectsAuke G. Talma, Patrick Jouin, Johannes De Vries, C. B. Troostwijk, Gerard H. Werumeus Buning, Jan K. Waninge, Johnny Visscher, Richard M. KelloggCite this: J. Am. Chem. Soc. 1985, 107, 13, 3981–3997Publication Date (Print):June 1, 1985Publication History Published online1 May 2002Published inissue 1 June...

Abstract Degradation of rubber vulcanizates in the presence and absence air as well ozone is reviewed this paper. The paper also outlines means to overcome undesirable phenomenon. Under anaerobic aging conditions, which termed reversion, are exposed elevated temperature oxygen. consequence process reflected a decline physical properties performance characteristics. These changes directly related modifications original crosslink structure. Decomposition reactions tend predominate thus leading...

Abstract Migration of compounding ingredients is an important factor in the overall properties and performance rubber articles containing a number layers for example, tire, hose or conveyor belt. In certain cases, migration before, during after vulcanization compounds can be benefit. For waxes p-phenylenediamines antiozonants rely heavily on mechanism to provide optimum protection products service against degradation by ozone. addition, dispersion such as oil, curatives, antidegradants...

Abstract Among short fiber‐reinforced composites, those with rubber matrices have gained great importance due to the advantages they in processing and low cost, coupled high strength. These composites combine elastic behavior of rubbers strength stiffness fibers. Reinforcement fibers offers attractive features such as design flexibility, modulus, tear strength, etc. The degree reinforcement depends upon many factors as: nature matrix, type fiber, concentration orientation fibers, fiber...

The performance of fibre-reinforced composites is strongly dependent on the nature and strength fibre–matrix interface. Good interfacial bonding required to ensure load transfer from matrix reinforcing fibres. For rubber-reinforced composites, resorcinol formaldehyde latex (RFL) known as a fibre surface coating which able provide good adhesion between rubber In present study, aramid fibres are investigated, because their significantly higher modulus strength, compared other commercial Their...

ABSTRACT There is a renewed interest in the application of short aramid fibers elastomers because considerable improvement mechanical and dynamic properties corresponding rubber composites. Possible applications fiber–reinforced are tires, dynamically loaded seals, diaphragms, engine mounts, transmission belts, conveyer hoses. Our studies related to investigation dispersion, length distribution, fiber–matrix interaction two types fibers, standard coated resorcinol formaldehyde latex (RFL)...

The disposal of tires at the end their lifespan results in societal and environmental issues. To tackle this, recycling reuse are effective solutions. Among various methods, devulcanization is considered to be a very sustainable option, as it involves controlled breakdown crosslinks while maintaining polymer backbones. objective this study develop process for passenger car tire rubber using silanes. In study, thermo-mechanical–chemical was conducted screen six potential aids (DAs). Silanes...

Composites revolutionize material performance, fostering innovation and efficiency in diverse sectors. Elastomer-based polymeric composites are crucial for applications requiring superior mechanical strength durability. Widely applied automotives, aerospace, construction, consumer goods, they excel under extreme conditions. based on recycled rubber, fortified with reinforcing fillers, represent a sustainable by repurposing discarded rubber. The integration of agents enhances the resilience...

The tire industry needs to become more sustainable reduce pollution and fight climate change. Replacing fossil ingredients in a tire-tread compound with bio-based alternatives is an approach create product. For instance, the plasticizer can be replaced, which petroleum-based ingredient used relatively high amounts rubber. This was followed current study. Three plant-based plasticizers were selected as potential substitutes for treated distillate aromatic extract (TDAE) simplified...

Since Charles Goodyear discovered the method of sulfur curing Natural Rubber in 1839, many studies have been carried out to understand its mechanism. Currently, broadly accepted mechanism includes an activated accelerator complex formed by Zinc oxide, stearic acid, accelerators and sulfur. Furthermore, it is also that coupling polymer takes place allylic position double bond. Modern passenger car tire treads no longer contain but instead a blend Solution Styrene Butadiene Rubber, filled with...

The performance of fibre-reinforced composites is strongly dependent on the nature and strength fibre–matrix interface. Good interfacial bonding required to ensure load transfer from matrix reinforcing fibres. For rubber-reinforced composites, resorcinol formaldehyde latex (RFL) known as a fibre surface coating which able provide good adhesion between rubber But this substance in many cases can be largely affected due exposure coated fibres air light. Moreover, most data available literature...

ABSTRACT Sulfur donors are used commonly in rubber crosslinking, usually conjunction with elemental sulfur. In the crosslinking process, sulfur release situ free The difference between two donors, bis(triethoxysilylpropyl)-tetrasulfide (TESPT) and cyclic tetrasulfide (CTS), both of which contain at least one tetrasulfidic group molecule, is analyzed. Chemical model studies deployed to assess chemical reactivity molecules. was observed reaction 2,3-dimethyl-2-butene, as followed by Raman...

Synthese a partir de pyrocatechol et dimesylates d'oligoethyleneglycols par une cyclisation en presence carbonate cesium, suivie d'acetylation, reduction alcool deshydratation. Etude RX du complexe vinyl benzo-27-crown-9 avec le perchlorate guanidinium

Abstract Peroxide cure is an important and widely used system for rubber. Several properties obtained via peroxide vulcanization are superior not achievable with sulfur vulcanization, e.g.: aging resistance, no reversion low compression set. However, other such as tensile strength dynamic properties, inferior to those of vulcanizates. The use co-agents in leads a certain extent improvement mechanical strength. Nevertheless the still respect mechanical/dynamical sulfur-cured articles. If...

Abstract Surface modification of carbon black by plasma polymerization was aimed to reduce its surface energy in order compatibilize the filler with various elastomers. A fullerenic used for process. Thermogravimetric analysis, wetting behavior liquids known tension, TEM and TOF‐SIMS were characterize before after modification. The state plasma‐coated rubber studied means conductivity measurements. modified using Payne effect stress/strain properties. study shows that results a better...

A new concept is introduced in this study, suggesting the role played by ZnO crystal sulfur crosslinking polymers, particularly, rubber blends of EPDM-CTS. The study conducted a polymer blend ethylene propylene diene terpolymer (EPDM) and cyclic tetrasulfide (CTS). CTS reactive low molecular weight polymer, which can act as donor. It proposed that occurs at surface crystals. reaction site created on with stearic acid, creates "template" or active catalytic for to take place. Various...

Abstract The mechanism of biscitraconimides (BCI) as antireversion agents for sulfur vulcanized diene rubber was investigated choosing squalene a model substrate. Curing with in the presence accelerator, activator and BCI at 170°C gave bridged adducts. products were identified by spectroscopic methods being results Diels-Alder reaction (dienophile) conjugated polyenes that are formed result reversion. rate which network degrades is comparable to adduct formed. As this, nearly constant...

Since Charles Goodyear discovered the sulfur curing of Natural Rubber in 1839, many studies were carried out to understand mechanism curing. Nowadays, broadly accepted includes an activated accelerator complex formed by Zinc oxide, stearic acid, accelerators and sulfur. Furthermore, it is also that coupling polymer takes place allylic position double bond. Modern passenger car tire treads do not contain any longer but a blend SSBR BR, filled with silica /silane system. Is possible transfer...

Abstract Tire sidewalls generally consist of blends natural rubber (NR) and butadiene (BR), containing a high concentration antiozonants to provide ozone resistance. However, the most widely used antiozonant, N-(1, 3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine (6PPD), is staining, toxic environmentally unfriendly substance. Incorporation Ethylene-Propylene-Diene (EPDM) into NR/BR way achieving non-staining But blending dissimilar rubbers severely restricted due viscosity mismatch,...

ABSTRACT Rubber is a challenging composite material, whose functionality strongly depends on the affinity of different materials in and its morphology. One way to tailor polarity chemistry filler surface plasma coating. When using acetylene, thiophene, or pyrrole as monomers, coating results reduced compared with untreated silica, unsaturated C–C bonds are formed surface. This improves compatibility filler–polymer blends. In SBR/EPDM blend, improved for all plasma-coated fillers silica. The...