New thermoplastic poly(carbonate-urethane)s based on diphenylethane-derivative chain extenders—the effect of chain extender structure on thermal and mechanical properties

بررسی اثر زنجیرافزاینده 4،4 َ- بیس(فنیل آمین) متان بر خواص مکانیکی و حرارتی شبکه‌ پلی‌اوره- یورتان بر پایه HTPB

Polyurea-urethanes are one of the polyurethane categories that causes better phase separation due to increasing the hard segment length and non-covalent interactions. In this research, hydroxyl-terminated polybutadiene based polyurea-urethanes have been synthesized via one-pot polymerization of triethanol amine triflouroborate comlex as cross-linker, isophoron diisocyanate as curing agent and v...

Influence of Hard Segments on the Thermal, Phase-Separated Morphology, Mechanical, and Biological Properties of Polycarbonate Urethanes

In this study, we have fabricated a series of polycarbonate polyurethanes using a two-step bulk reaction by the melting pre-polymer solution-casting method in order to synthesize biomedical polyurethane elastomers with good mechanical behavior and biostability. The polyurethanes were prepared using dibutyltin dilaurate as the catalyst, poly(1,6-hexanediol)carbonate microdiols (PCDL) as the soft...

fabrication of new ion sensitive field effect transistors (isfet) based on modification of junction-fet for analysis of hydronium, potassium and hydrazinium ions

a novel and ultra low cost isfet electrode and measurement system was designed for isfet application and detection of hydronium, hydrazinium and potassium ions. also, a measuring setup containing appropriate circuits, suitable analyzer (advantech board), de noise reduction elements, cooling system and pc was used for controlling the isfet electrode and various characteristic measurements. the t...

Thermal and Morphological Properties of Thermoplastic Elastomer Nanocomposites Based on PA6/NBR

the effect of genre-based teaching on reading comprehension of literary texts

تحقیق حاضر به بررسی کاربرد روش ژانر-محور را در محیط آموزش زبان عمومی می پردازد.روش ژانر-محور به زبان آموزان کمک میکند که در زمینه خوانش پیشرفت کنند. بعضی از محققین معتقد اند که روش تدریس ژانر-محور به تدریج به زبان آموزان کمک می کند تا در درک ژانر های مختلف مهارت یابند (هایلند 2004).همچنین امروزه توجه روز افزونی به اهمیت استفاده از ادبیات در برنامه آموزشی زبان انگلیسی (esl/efl ) شده است. زمانی ک...