In this study, we focus on qualitative differences in the network structure and dynamics of natural as well poly(butadiene) rubber dependence cure system (sulfur/accelerator or organic peroxide) used vulcanization process. The spatial homogeneity distribution chemical physical cross-links is assessed via quantitative measurement proton−proton residual dipolar couplings measured by static multiple-quantum (MQ) NMR spectroscopy at low field. experiment also provides information apparent...

The network structure and chain dynamics of ionic elastomers based on carboxylated nitrile rubber (XNBR) cross-linked with different content magnesium oxide (MgO) have been studied by low-field time-domain NMR experiments. Ionic contacts created during the vulcanization tend to aggregate trapping some polymer segments that show restricted mobility as it was quantified analyses refocused free induction decays. Increasing MgO above stoichiometric fraction has no effect amount trapped segments,...

The homogeneous dispersion of carbon nanotubes (CNTs) in a rubber matrix is key factor limiting their amazing potential. CNTs tend to agglomerate into bundles due van der Waals interactions. To overcome this limitation, have been surface-modified with oxygen-bearing groups and sulfur. Using atomic force microscopy (AFM) techniques, deep nanoscale characterization the morphology, degree styrene butadiene (SBR) matrix, thickness interfacial layer was carried out study. In context, results from...

Shape-memory elastomers based on a commercial rubber cross-linked by both ionic and covalent bonds have been developed. The elastomeric matrix was carboxylated nitrile (XNBR) vulcanized with magnesium oxide (MgO) providing interactions that form hierarchical structures. so-named transition is used as the unique thermal responsible for shape-memory effect (SME) in these elastomers. These fix temporary shape due to their behavior dynamic cross-links temperature changes. Covalent were...

The design of smart photoelectrodes is searched to modulate and control the spatio-temporal production reactive oxygen species (ROS). In this work, we develop photoactive films with tunable nanostructured morphologies...

The deficient management of plastic waste has caused a serious worldwide environmental problem. Thus, one the main challenges for industry in plastics sector contributing to sustainability and circular economy consists providing subsequent service life this waste. For that purpose, appropriate incorporation antioxidants will play key role preventing or postponing degradation waste, where formation radicals is initiated during its previous lifetime by action degrading agents. Functionalized...

This study evaluates the formation of radical species in natural rubber (NR) and poly-isoprene (IR) during vulcanization process uniaxial deformation formed networks by means Electron Spin Resonance (ESR).Vulcanization NR IR always shows a pathway, where different systems dictate concentration course this complex process.The greatest radicals were detected with sulfur/accelerator based on efficient (EV), followed conventional (CV) sulfur donor systems, whereas azide organic peroxide agents...

Abstract An experimental approach based on the freezing‐point depression of a solvent in swollen gel has been developed to characterize structure rubber networks. This property depends conditions required for formation crystalline nuclei, which are limited by elastomer network restrictions. Information about functionality, spatial distribution, and number crosslinks can be obtained use this easy ready method. Application tube model elasticity uniaxial stress–strain experiments natural...

Abstract A step forward in the understanding of rubber vulcanization with organic peroxides is provided by combining a proper arrangement between polymer, vulcanizing agent and cure conditions. For this purpose, an ethylene–vinyl acetate copolymer high content vinyl (70 mol%) was used since fully saturated polymer backbone allows its via peroxide. range conditions analysed here, it shown that predominant process taking place crosslinking radical recombination, minimizing or even avoiding...

The outstanding properties of carbon nanotubes (CNTs) present some limitations when introduced into rubber matrices, especially these nano-particles are applied in high-performance tire tread compounds. Their tendency to agglomerate bundles due van der Waals interactions, the strong influence CNT on vulcanization process, and adsorptive nature filler–rubber interactions contribute increase energy dissipation phenomena rubber–CNT Consequently, their expected performance terms rolling...

Abstract The use of fatty amines, obtained from natural acids, in rubber compounds to improve silica dispersion was evaluated. Fatty amines can interact with the free silanol groups bis(3‐triethoxysilyl‐propyl) tetrasulfide (TESPT) silane‐modified forming an amine‐modified complex, which reduces hydrophilic nature surface, minimizing silica–silica interactions, and reducing formation secondary structures silica. effect addition different and/or polyethylenglycol SBR loaded Finally,...

Abstract The cure of polybutadiene rubber (BR) with sulfur donor dipentamethylene thiuram tetrasulfide (DPTT) does not show reversion reaction, in contrast similar natural compounds. No polysulfure links are formed; whereas a great amount CC crosslinks produced. addition tetramethyl monosulfidic (TMTM) strongly affects the crosslinking process. Mechanical properties cured compounds poor. In DPTT, curing BR radical species produced through homolitic cleavage DPTT molecule seems to have...

Abstract The effect of the temperature on kinetics vulcanization natural rubber with sulfur donor agent dipentamethylene thiuram tetrasulphide (DPTT) was investigated. oscillatory disk rheometer and differential scanning calorimetry under dynamic isothermal conditions were used. Coran's model applied to set kinetic constants within each distinct step process using obtained values curves. During curing period it observed that there two stages. Either torque increment (Δ S ) or crosslink...

Abstract The influence of some paraffinic oils on rheological properties, dynamic and behavior at low temperature various ethylene–propylene–diene monomer rubber (EPDM) compounds was studied. Three different types EPDM, Dutral TER 4049, Ter 4038, Nordel IP 4770 R, five were used. properties the evaluated with reference to oil characteristics: viscosity, composition, glass transition temperature, solubility parameter. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1825–1834,

ABSTRACT There are currently many well-established applications for recycled rubber from end-of-life tires (ELT), but it is essential to investigate and seek new approaches enhance the value of these products. Recent developments in technologies innovative recycling devulcanization processes have opened up perspectives ELT crumb rubber. To promote use products newly added applications, develop optimize methods that allow characterization parameters related ultimate properties potential final...

Several aromatic mono- and dicyanate monomers bearing ether ketone groups in the main chain have been synthesized through high-yield reactions widely used organic chemistry. FT-IR NMR were to characterize these intermediate products. The cyclotrimerization reaction was studied by DSC monocyanate models, enthalpy of determined. value obtained approximately 95 kJ/mol cyanate irrespective substituent symmetry substitution. For short dicyanates, did not reach completion, for long could be...

Abstract The effect of some processing aids, Redex‐2, Redex‐SP‐2, and Redex‐A, on rheological properties, tensile dynamic mechanical properties natural rubber compounds has been studied. optimum level these additives was determined the changes caused by use were evaluated comparison with an additive‐free control compound mixed under similar conditions. Redex‐2 Redex‐SP‐2 improve processability compounds, giving a reduction both Mooney viscosity shear viscosity, but concentration aid...