Semi-Circular Bending (SCB) Test is a fast and accurate three-point bending test, which was originally used in rock mechanics. SCB test is going to be an accepted test method for asphalt concrete pavements. Different asphalt-mixture property-values such as tensile strength, stress intensity factor and fatigue can be obtained by this test. In this study, static and dynamic tests including SCB te...

Short-chain branching in polyethylene, which involves a six-centre transition state, is studied by ab initio quantum mechanics up to the QCISD(T) level. The calculation gives a (low-pressure) activation energy of 73 kJ mol and a frequency factor of 4:8 × 10 s: The frequency factor for this six-centre transition state is expected to be of acceptable accuracy and also applicable to homologous sys...

The role of short chain branches (SCBs) (C4H9) on the melt and crystalline properties monodisperse polyethylene systems (C400H802) is investigated, using molecular dynamics simulations a coarse-grained united-monomer model that represents chemical monomer as one particle. A method introduced, whereby SCBs are grown out linear backbone to minimize computational expense. Here, this concept proven...

The influence of topology on the strain hardening in uniaxial elongation is investigated using monodisperse comb and dendrigraft model polystyrenes (PS) synthesized via living anionic polymerization. A backbone with a molecular weight Mw,bb = 310 kg mol−1 used for all materials, while number 100 short (SCB, Mw,scb 15 mol−1) or long chain branches (LCB, Mw,lcb 40 are grafted onto backbone. LCB s...

Background Specific growth factors and feeder layers seem to have important roles in in vitro embryonic stem cells (ESCs) differentiation. In this study,the effects of bone morphogenetic protein 4 (BMP4) and mouse embryonic fibroblasts (MEFs) co-culture system on germ cell differentiation from mouse ESCs were studied. MaterialsAndMethods Cell suspension was prepared from one-day-old embryoid bo...

Low Density Polyethylene (LDPE) is produced by free radical polymerization. Industrially, LDPE polymerization process is usually carried out in a continuous mode (tubular or autoclave reactors) at high pressures (1300-3400 atm) and temperatures (50-340 0 C). LDPE exhibits a number of desirable properties, including high tensile strength, flexibility, high impact resistance, low crystallinity, l...

sio2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade hdpepipe materials. the control of the short chain branch (scb) distribution using this catalyst system is still a greatchallenge. in this work, ethylene and 1-hexene copolymers were synthesized using sio2-supported silyl chromatecatalyst combined with triisobutylaluminium (tiba), triethylalu...

Chromium-vanadium (Cr-V) bimetallic catalysts are prepared by the introduction of vanadium into the Phillips catalyst which is one of the most significant industrial ethylene polymerization catalysts for tuning the Phillips catalyst performances and improving polyethylene properties. In the present work, titanium species were introduced into the fluorine-modified chromium-vanadium bimetallic ca...

In this study, the compatibility of the blends of polypropylene (PP) and polybutene-1(PB-1) homopolymer before and after long chain branching process were studied. The blends were prepared and long-chain branched directly via reactive extrusion process in presence of free radical initiator and trimethylolpropane tri methacrylate (TMPTMA) poly functional monomer. The optimum percentage of TMPTMA...