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Abstract In this paper, two Zigler-Natta catalysts (ZNCs) were used to synthesize a commercially available linear low-density polyethylene (LLDPE), widely used in the packaging industry, on an industrial scale. The [...]

The relationship between career resin of carbon black (CB) masterbatch and the performance of bimodal polyethylene pipes (PE100) under ultraviolet (UV) irradiation and the long-term stability of black PE100 with different comonomer content have been investigated. For this purpose, two different CB masterbatches varying in carrier resin were selected and added to two PE100 pipes. Samples were exposed to UV irradiation, and then thermal, mechanical, and rheological properties were explored using differential scanning coloriemetry (DSC), tensile, and rheometry analyses. Additionally, Fourier transformed-infrared spectroscopy (FTIR) has been performed to characterize the structural changes of PE100 samples under UV irradiation. According to rheological results, the PE100 sample containing more comonomer underwent a higher degree of degradation. Thermal and mechanical results reveal that the masterbatch composed of highdensity polyethylene (HDPE) as carrier resin has a better influence on PE pipes' UV stability with less comonomer content. KEYWORDS carbon black, HDPE, photodegradation, pipe, rheology, UV irradiation, UV stability, 1 | INTRODUCTION Easy to install, light, flexible, and corrosion-free are the features that have made polyethylene (PE) pipes a material of choice for the network of gas and water [...]

This study integrates advanced mathematical modeling and experimental methodologies to investigate the simultaneous impact of modifications in the split ratio and molecular weight (MW) of chains on the rheological and mechanical properties of bimodal polyethylene (BiPE) resins. The outcomes underscored the viability of fine‐tuning the molecular weight distribution (MWD) of a BiPE resin by augmenting the MW of high molecular weight (HMW) chains while simultaneously diminishing their proportion in the final alloy formulation. In addition, the experimental results illuminated the prospect of attaining a targeted melt flow index for the final polymers by elevating the MW of HMW chains alongside an increase in the proportion of low molecular weight chains. Significantly, these adjustments resulted in remarkable enhancements in the shear thinning index and strain hardening modulus of the fabricated resins. [ABSTRACT FROM AUTHOR]

The present study encompasses the utilization of a mixture of 1-butene and 1-hexene comonomers for the large-scale production of a film-grade linear low-density polyethylene (LLDPE) resin. The goal involves assessing the impact stemming from the partial replacement of 1-butene with 1-hexene on the thermal, physical, mechanical and rheological properties of the resultant resin, juxtaposed against an LLDPE counterpart exclusively produced by 1-butene as the comonomer. Although the comprehensive examination of key physical, thermal, rheological and mechanical characteristics indicates nominal influence due to the substitution, a marked escalation materializes in both the tear resistance and slow crack growth (SCG) resilience of the LLDPE resins formulated through the amalgamation of these comonomers. Specifically, the tear and SCG resistance of the proposed resin exhibit an extraordinary surge exceeding 60% and 30%, respectively. This discernible enhancement underscores the viability of the proposed technique as a propitious avenue for augmenting the requisite mechanical properties, obviating the need for an all-encompassing shift from 1-butene to longer-chain α-olefin comonomers. [ABSTRACT FROM AUTHOR]

The process of hydrocarbons cracking is carried out in the presence of heat‐resistant alloys Fe‐Ni‐Cr, which HP40 alloy (25Cr‐35Ni) has the most applications among olefin plants. Since these alloys naturally tend to form coke, the industry has always tried to reduce the coke formation by reducing the catalytic properties of the coils. In this research, the effect of dimethyl disulphide (DMDS) concentration (200–900 ppm) on the HP40 alloy of industrial coils at the presulphidation stage is evaluated. In the presulphidation stage, the alloy surface is in contact with sulphur in the absence of hydrocarbons, and this affects the amount of coke formation in the cracking process. Also, the surface composition and morphology of coke are identified using EDX and SEM analysis. These results showed that at the 500 ppm concentration of DMDS, coke deposition is minimized. Additionally, our findings indicated that coke morphology has not changed under different presulphidation conditions, and coke is still a filament type, but the size of the filaments has changed. Moreover, the study of HP40 composition in both preoxidized and presulphide stages shows that presulphidation reduces the amount of Fe and Ni in the coke layer significantly. [ABSTRACT FROM AUTHOR]