In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copolymer, synthesized using Phillips catalyst, on thermal behavior parameters such as: crystallization, melting temperature and thermal degradation was investigated in detail. The copolymer was fractionated to homogenous short-chain branching (SCB) fractions by "preparative temperature rising elution fra...

The effect of short-chain branching (SCB) on the persistence length lp of polyethylene (PE) was studied using small-angle neutron scattering (SANS). In thermodynamically good solvents, lp can be measured directly from the scattering vector qtr at the crossover from good solvent mass-fractal scaling to the rodlike persistent scaling, using the unified equation described in the text. The method w...

The influences of short chain branching (SCB) and molecular weight (Mw) of low density polyethylene (LDPE) on its melt miscibility with polypropylene (PP) were investigated by rheological techniques. Rheological measurement and different data-treatment techniques as well as rheological models suggest that blends of PP with LDPE of high SCB (22 CH3/1000 C) are miscible at all compositions. Howev...

The influences of short chain branching (SCB) and molecular (Mw) weight of low density polyethylene (LDPE) on the solid state properties of polypropylene (PP)-LDPE blends were investigated by mechanical and thermal techniques. DSC analysis of all blends exhibit a double melting peak at all compositions studied thus suggesting that both PP and LDPE crystals exist separately in the solid state. I...

Polyethylenes (PE) are the most commonly occurring ingredients for post-consumer recyclates (PCR). The structure–property relationships of different types model PE-based blends established using multiple thermo-rheological analyses. Although considered “simple”, complex behavior is experimentally demonstrated first time metallocene-catalyzed, linear, low-density polyethylenes (mLLDPE) with micr...

Herein a quenched-flow kinetic technique was applied to calculate the rate constants of 1-hexene and 1-octene oligomerization catalyzed by the Cp2ZrCl2 and Cp2HfCl2/MAO catalyst systems, and subsequently a mechanism for the higher α-olefin oligomerization reaction was proposed. The oligomerization results showed that Zr-based catalyst in the oligomerization of 1-octene had the highest activity ...

High-density polyethylene (HDPE) has a linear structure with very little or no branching and possesses a high degree of crystallinity, but it is difficult to process. Low-density polyethylene (LDPE) however has a chaotic structure with short and long branches and is easy to process. Blending of polyethylenes (PEs) is a common industrial practice. The principal reasons behind the blending of PEs...

SiO2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade HDPE pipe materials. The control of the short chain branch (SCB) distribution using this catalyst system is still a great challenge. In this work, ethylene and 1-hexene copolymers were synthesized using SiO2-supported silyl chromate catalyst combined with triisobutylaluminium (TIBA), triethyl...

In this work, the effect of hexyl branch content on thermal behavior of a fractionated ethylene/1-octene copolymer with emphasis on high temperatures was investigated. The ethylene/1-octene copolymer was carefully fractionated to different fractions with homogenous hexyl branch (HB) content by preparative temperature rising elution fractionation (P-TREF) method. The P-TREF fractions were therma...

In the present study, influence of electron-beam irradiation on plasticity-controlled and crack-growth-controlled failure in high-density polyethylene (HDPE) is investigated effect both molecular weight distribution (MWD) short chain branching (SCB) content are taken into account. Size exclusion chromatography (SEC) used to study evolution MWD sol fraction as a function dose. Here, it seen that...