Natural rubber (NR) is incompatible with hydrophilic additives like halloysite nanotubes (HNT) due to their different polarity. The silane coupling agent is the ideal component to include in such a compound to solve this problem. Many types of silane are available for polymer composites depending on their functionalities. This work aimed to tune it to the composite based on NR and HNT. Four different silanes, namely Bis[3- (Triethoxysilyl)Propyl]Tetrasulfide (TESPT), 3-Aminopropyl triethoxysilane (APTES), N-[3-(Trimethoxysilyl)Propyl] Ethylenediamine (AEAPTMS), and Vinyltrimethoxysilane (VTMS) were used. Here, the mechanical properties were used to assess the properties, paying close attention to how their reinforcement influenced their crystallization behavior after stretching. It was revealed that adding silane coupling agents greatly improved the composites' modulus, tensile strength, and tear strength. From the overall findings, AEAPTMS was viable for NR/HNT composites. This was in direct agreement with the interactions between NR and HNT that silanes had encouraged. The findings from stress-strain curves describing the crystallization of the composites are in good agreement with the findings from synchrotron wide-angle X-ray scattering (WAXS). The corresponding silanes have substantially aided the strain-induced crystallization (SIC) of composites.
Thymoquinone (TQ) is the main constituent of black seed (Nigella sativa, spp) essential oil which shows promising in vitro and in vivo anti-neoplastic activities in different tumor cell lines. However, to date there are only a few reports regarding the apoptotic effects of TQ on cervical cancer cells. Here, we report that TQ stimulated distinct apoptotic pathways in two human cervical cell lines, Siha and C33A. TQ markedly induced apoptosis as demonstrated by cell cycle analysis in both cell lines. Moreover, quantitative PCR revealed that TQ induced apoptosis in Siha cells through p53-dependent pathway as shown by elevated level of p53-mediated apoptosis target genes, whereas apoptosis in C33A cells was mainly associated with the activation of caspase-3. These results support previous findings on TQ as a potential therapeutic agent for human cervical cancer.
Carbonized natural filler can offer the production of low cost composites with an eco-friendliness value. The evolving field of electronics encourages the exploration of more functions and potential for carbonized natural filler, such as by modifying its surface chemistry. In this work, we have performed surface modification on carbonized wood fiber (CWF) prior to it being used as filler in the ethylene vinyl acetate (EVA) composite system. Zinc chloride (ZnCl2) with various contents (2 to 8 wt%) was used to surface modify the CWF and the effects of ZnCl2 composition on the surface morphology and chemistry of the CWF filler were investigated. Furthermore, the absorptive, mechanical, thermal, and electrical properties of the EVA composites containing CWF-ZnCl2 were also analyzed. SEM images indicated changes in the morphology of the CWF while FTIR analysis proved the presence of ZnCl2 functional groups in the CWF. EVA composites incorporating the CWF-ZnCl2 showed superior mechanical, thermal and electrical properties compared to the ones containing the CWF. The optimum content of ZnCl2 was found to be 6 wt%. Surface modification raised the electrical conductivity of the EVA/CWF composite through the development of conductive deposits in the porous structure of the CWF as a channel for ionic and electronic transfer between the CWF and EVA matrix.
A massive demand for rubber-based goods, particularly gloves, was sparked by the emergence of the COVID-19 epidemic worldwide. This resulted in thousands of tons of gloves being scrapped due to the constant demand for the items, endangering our environment in a grave way. In this work, we aimed to focus on the utilization of waste nitrile gloves (r-NBR) as a component blended with natural rubber (NR). The life span and other related properties of the blend can be improved by proper control of the chemical recipe. This study assessed three types of crosslinking systems, namely sulfur (S), peroxide (DCP), and mixed sulfur/peroxide (S/DCP) systems. The results indicate that choosing S/DCP strongly affected the tensile strength of the blend, especially at relatively high contents of r-NBR, improving the strength by 40-60% for cases with 25-35 phr of r-NBR. The improvement depended on the crosslink types induced in the blends. It is interesting to highlight that the thermal resistance of the blends was significantly improved by using the S/DCP system. This indicates that the life span of this blend can be prolonged by using a proper curing system. Overall, the S/DCP showed the best results, superior to those with S and DCP crosslinking systems.