Nabila. A. Darwish

The growth rate of plastic manufacturing all over the world and in the middle east as oil producing countries increased the rate of thermoplastics production and the needs of reference materials (RMs) for use in performance evaluation of measuring instruments and ensuring validity of measurement results. This article was focused on the preparation of RM based melt mass-flow rate from low-density polyethylene (LDPE) according to ISO 1133-1 standard. The characterization was evaluated from around 10% of prepared units, then the samples were distributed to a network of collaborating laboratories in order to ensure the validity of the RM production process. The value of melt mass-flow rate of LDPE was determined to be 19.51 g/10 min under a temperature of 190℃ and a load of 2.16 kg with expanded uncertainty 0.38 at 95% confidence level. The obtained values were confirmed from the data reported by the network of collaborating laboratories.

In this work, the effect of multi-walled carbon nanotubes (MWCNTs) coated by two resins, namely unsaturated polyester (R1) and urethane alkyd resin (R2) on mechanical, electrical, wear properties, and adhesion strength of natural rubber (NR)/nylon 66 systems before and after UV exposure was studied. Three different loadings of CNTs (i.e. 0.5, 1.5, and 3 wt.%) were used and characterized by X-ray diffraction. Transmission electron microscopy images of coated CNTs nanocomposites confirmed that better dispersion of nanofiller in the NR matrix occurred at 1.5 wt.%. The results revealed that the use of 1.5 wt.% CNTs coated by R1 resin increased the tensile strength by 340% compared to unfilled NR. Also, the electrical behavior and the wear resistance of NR nanocomposites were enhanced. Pull-out adhesion tests clarified that the adhesion force of NR/R1-1.5% was nearly twice that of the pristine NR and showed the best adhesion, especially for unexposed samples. While for exposed samples, the results showed inferior adhesion values in most matrices. Scanning electron microscopy utilized to demonstrate the failure mechanism of adhesion for investigated samples between the rubber and nylon 66 cords after pull-out tests.

The need of using biodegradable fillers as polymer reinforcements instead of the polluting and hazard fillers has recently become a very important issue. Therefore, the aim of this study was the utilization of date stones (DS) as reinforcing and flame retardant biofiller in polyamide‐6 (PA6) with and without maleic anhydride‐grafted polypropylene (PP‐g‐MAH) compatibilizer. The composition of DS powder was revealed by X‐ray fluorescence (XRF) and chemical methods. Scanning electron microscopy images of biocomposites showed better compatibility of filler/polymer interface at 20 wt% DS and 5 wt% of the compatibilizer. Fourier transform infrared spectroscopy (FTIR) results confirmed our suggested reaction mechanism. The dynamic data showed satisfied enhancement in the storage modulus (E′) for maleated PA6 at 20 wt% DS filler. The tensile and impact strengths of the biocomposites enhanced for maleated PA6. The presence of the biofiller had no distinct effect on the thermal stability of the biocomposite. The flame retardant properties significantly improved with increasing DS filler content. The X‐ray diffraction and FTIR data revealed that the char layer acted as an insulating barrier to oxygen and heat transfer between the gas phase and the condensed phase thus reduced the heat release rate during the burning. POLYM. COMPOS., 39:1978–1987, 2018. © 2016 Society of Plastics Engineers

The seashell is mainly composed of calcium carbonate and organic materials which, when decompose, produce harmful gases with significant odor and toxicity. Therefore, their wastes are considered to be a problem and could be hazardous to human. To overcome this problem, this study proposed to use grinded seashell wastes (SS) as a bio‐filler to reinforce acrylonitrile–butadiene–styrene copolymer (ABS). Commercial calcium carbonate, CaCO₃ (CC) was also used to compare the results. The filler and their composites were characterized by X‐ray Fluorescence (XRF), X‐ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT‐IR), Scanning Electron Microscopy (SEM), Dynamic Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA), and Cone Calorimeter. DMA data show that the addition of low amounts of seashell bio‐filler to ABS increases the storage modulus (E′). The glass transition temperature (T_g) values are shifted to higher temperature. On the other hand, the ABS/SS composite shows a higher tensile strength than CC filled ABS. TGA results exhibit that there is an enhancement in the thermal stability when calcium carbonate from seashell is added. Good flame retardant properties were achieved with increasing the bio‐filler content. According to XRD and FT‐IR results of the char residues after cone calorimetric tests, the compact char layer acts as a barrier to oxygen and heat transfer, preventing the escape of polymer fragments to the gas phase, and decreasing the heat release rate during combustion. POLYM. COMPOS., 38:2788–2797, 2017. © 2015 Society of Plastics Engineers

Bonding rubber to metal is a multifaceted combination of metallurgy, surface science, adhesion science, rubber chemistry, and process engineering, with a multitude of interactions. In all aspects of bonding, scrupulous cleanliness, adherence to process controls and meticulous attention to detail are essential if good adhesion is to be attained on a consistent production basis. In this review article we discuss different aspects of rubber to metal adhesion with emphasis on the mechanisms of rubber to metal adhesion, different types of adhesive systems, and bond properties and bond failure. Breakthroughs in rubber to metal adhesion technologies and the current status of the industry as well as novel alloys used in rubber to metal bonding, especially brass plated steel cords, are highlighted in this review.

In this article, rice husk flour filler/polypropylene (RH/PP) composites with different ratios of the filler were prepared without and with maleated PP, which was used as a compatibilizer. The RH filler in the RH/PP composites was treated with acid and alkali, and their mechanical properties were measured. The mechanical properties were improved with the addition of the compatibilizer. In this study, grafting of maleic anhydride (MA) onto PP with different ratios of benzoyl peroxide (BPO) and MA was prepared. Infrared analysis showed characteristic bands at 1786 and 1863 cm⁻¹ for the grafted sample (maleated PP). Also, from chemical titration, the optimum MA and BPO contents were 4 and 1 part per hundred parts (php of polymer), respectively. The results showed that the morphology of the grafted sample was a flat with coarse surface, and that of the composite clearly elucidated that the interfacial bonding between RH and PP was enhanced by the presence of the compatibilizer. Thermal stability of the grafted PP was enhanced by the grafting process. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012