Abstract It is well-recognized that different sulphur curing systems have greatly influenced to the final properties of the rubber vulcanizates. In this study, the properties of vulcanizates with conventional vulcanization (CV) and efficiency vulcanization (EV) systems were correlated in the aspect of stress relaxation and thermal stability. The stress relaxation behaviour and thermal stability were studied with the temperature scanning stress relaxation (TSSR) and with thermogravimatric analysis (TGA) techniques, respectively. Thermo-oxidative degradation of rubber chains in the CV system was greater than the EV system, leading to easier stress relaxation and poorer aging resistance of the CV system. Also, thermal stability of the rubber crosslinked with CV system was poorer than that with the EV system as corroborated by the activation energy of degradation. TSSR result correlated well with TGA result, and both revealed type of crosslinkages governed the thermo-oxidative degradation and thermal stability of vulcanizates.

Abstract Recycling of rubber waste and finding the effective methods to extend its use are one of major challenges nowadays. In the present study, waste natural rubber glove (wNRg) was used in an attempt to extend its use and create a value-added composite based on natural rubber (NR) and wNRg. Another interesting focus was to develop such material into a new Magnetorheological Elastomer (MRE). This MRE can be prepared by incorporating Ferromagnetic particles namely carbonyl iron (CI) to the rubber composite. Carbon black (CB) was also added to obtain MRE with remarkably mechanical properties. CI was fixed at 60 phr where the CB was varied from 10 – 30 phr. Higher thermal conductivity and magneticity in nature of CI had made the composites faster cure and higher magnetic strength. On the contrary, superior tensile strength, modulus and elongation at break were found in the presence of CB. From the experimental results, hybridization of 60/10 phr/phr of CI and CB is highly suggested to gain the synergistic strength and magneticity. This is expected to solve a big problem in the application of MRE.

Abstract It is well-recognized that different sulphur curing systems have greatly influenced to the final properties of the rubber vulcanizates. In this study, the properties of vulcanizates with conventional vulcanization (CV) and efficiency vulcanization (EV) systems were correlated in the aspect of stress relaxation and thermal stability. The stress relaxation behaviour and thermal stability were studied with the temperature scanning stress relaxation (TSSR) and with thermogravimatric analysis (TGA) techniques, respectively. Thermo-oxidative degradation of rubber chains in the CV system was greater than the EV system, leading to easier stress relaxation and poorer aging resistance of the CV system. Also, thermal stability of the rubber crosslinked with CV system was poorer than that with the EV system as corroborated by the activation energy of degradation. TSSR result correlated well with TGA result, and both revealed type of crosslinkages governed the thermo-oxidative degradation and thermal stability of vulcanizates.

Abstract Recycling of rubber waste and finding the effective methods to extend its use are one of major challenges nowadays. In the present study, waste natural rubber glove (wNRg) was used in an attempt to extend its use and create a value-added composite based on natural rubber (NR) and wNRg. Another interesting focus was to develop such material into a new Magnetorheological Elastomer (MRE). This MRE can be prepared by incorporating Ferromagnetic particles namely carbonyl iron (CI) to the rubber composite. Carbon black (CB) was also added to obtain MRE with remarkably mechanical properties. CI was fixed at 60 phr where the CB was varied from 10 – 30 phr. Higher thermal conductivity and magneticity in nature of CI had made the composites faster cure and higher magnetic strength. On the contrary, superior tensile strength, modulus and elongation at break were found in the presence of CB. From the experimental results, hybridization of 60/10 phr/phr of CI and CB is highly suggested to gain the synergistic strength and magneticity. This is expected to solve a big problem in the application of MRE.

The use of mineral fillers in rubber industry has been increasingly focused. Sepiolite is considered as one of the mineral fillers that exploits unique characteristics. This is due to its unique needle-like fibrous and a tunnel-like micro-pore channel structures. Therefore, adding this filler in natural rubber (NR) matrix would bring tremendous advantage. The study was carried out in the form of curing characteristics, tensile properties and morphology together with the dynamic properties. Filling sepiolite to NR has brought to a noticeable enhancement of curing characteristics, tensile properties and morphology. This is contributed to the distinctive structure of sepiolite itself, it provides a better dispersion to the NR. Surface roughness of the composites is visibly found which is responsible for the mechanical properties. Further verification was also monitored through the dynamic properties of the composites. The obtained profiles are in good agreement to the tensile properties and morphological characteristics observed.

The use of mineral fillers in rubber industry has been increasingly focused. Sepiolite is considered as one of the mineral fillers that exploits unique characteristics. This is due to its unique needle-like fibrous and a tunnel-like micro-pore channel structures. Therefore, adding this filler in natural rubber (NR) matrix would bring tremendous advantage. The study was carried out in the form of curing characteristics, tensile properties and morphology together with the dynamic properties. Filling sepiolite to NR has brought to a noticeable enhancement of curing characteristics, tensile properties and morphology. This is contributed to the distinctive structure of sepiolite itself, it provides a better dispersion to the NR. Surface roughness of the composites is visibly found which is responsible for the mechanical properties. Further verification was also monitored through the dynamic properties of the composites. The obtained profiles are in good agreement to the tensile properties and morphological characteristics observed.