in this work, new biodegradable abcba type pentablock copolymers with different mole ratio of l-lactide and ppdo-b-peg-b-ppdo triblock copolymer were synthesized and characterized. in the first step, ppdo-b-peg-b-ppdo triblock copolymer was synthesized via a ring-opening polymerization of p-dioxanone (pdo) monomer with poly (ethylene glycol) (peg) using stannous octoate (sn(oct)2) as the cataly...

Single phase BiFeO3 (BFO) nanoparticles as a visible light photocatalyst were successfully synthesized by thermal decomposition of the glyoxylate precursor. The glyoxylate precursors were formed by the redox reaction between ethylene glycol and nitrate ions. The phase evolution, structure and optical properties of BFO nanoparticles were characterized by X-ray diffraction, electron microscopy an...

thermoplastic polyurethane (tpu)/clay nanocomposites were prepared via a melt-compounding method using ester type tpu and two different modified organoclays (cloisite 30b and cloisite 15a) in different contents. the effects of the chemical structure and content of the nanoclays on the thermal degradation and mechanical properties of tpu were also investigated. the effect of structural modificat...

a one–dimensional, transient and thermal degradation model for predicting responses of composite materials when are exposed to the fire is presented. the presented model simulates ablation of composites with different layers of materials and considers material properties as functions of temperature. the reactions are modeled by using arrhenius-type parameters and density-temperature diagrams wh...

the thermal degradation of polyethylene (pe) was carried out in the absence and presence ofcatalystes x-zeolite and silica-alumina at different temperatures. the optimum pe/catalysisratio was 0.25:0.05 g/g, which produced highest degradation value. pe and pe/catalysis werecharacterized by thermogravimetric analysis. the thermal degradation properties of polymerhave been studied by infrared spec...

In nano-based microarchitectural design, achieving higher clock frequency is confronted with thermal restrictions especially with the presense of temperature-variant leakage power. While a module temperature depends both on power density and the thermal coupling with the neighboring blocks, thermal-aware floorplans have been introduced to reduce peak temperature. The major drawback is that the ...

A fixed-dose combination of atorvastatin and aspirin is widely used for the treatment of myocardial infarction. The present work describes a comprehensive study of the stress degradation behavior of atorvastatin and aspirin alone as well as in combination of 1:1 and 1:7.5 ratios, respectively, as per ICH guidelines. The degradation products of aspirin as well as atorvastatin were successfully s...

Liquid crystalline thermosetting epoxy, 4,4'-diglycidyloxy-α-methylstilbene (DOMS) was synthesized and characterized with cross-polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Carbon nanotube (CNT) or graphene reinforced DOMS composites were fabricated by melt blending with sulfanilamide (SAA) as a curing agent. To investigate the thermal degradation behavior, th...

BACKGROUND Biodegradable poly(L-lactic acid) (PLLA) is one of the most widely used polymer in biomedical devices, but it still has limitations such as inherent brittleness and acidic degradation products. In this work, PLLA blends with poly(L-lactide-ε-caprolactone) (PLCL) and Mg(OH)2 were prepared by the thermal processing to improve their physico-mechanical and thermal properties. In addition...