توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱The Evaluation of Psedue–Semi Interpenetrating Polyurethane network From FTIR and Swelling Test data based on polybutadiene–ol\polypropyleneoxide mixture
نویسنده(ها): ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۱۲
Polyurethane elastomer networks were designed and synthesized based on hydroxyl terminated polybutadiene\polypropyleneoxide (HTPB\PPO) mixtures, 2,4–toluene diisocyanate and 1,4– butanediol. Various networks with different molar ratio of HTPB to PPO (0\100, 25\75, 50\50, 75\25 and 100\0) had been prepared. DPS and HI factors caculated from FTIR spectrums. These factors show that chemical networks can increase hydrogen bonding and phase separation inpolyurethane networks based on non–polar or semi polar soft segments. Moreover Flory–Hugins interaction parameters of soft and hard segments were calculated. Swelling tests were carried out with different solvents. Time–dependent and Equlibrium swelling test were studied with good andbad solvent for hard and soft segment. Synthesized polyurethane elastomer networks have a structure similar to semi interpenetrating polymer networks, which is named pseudo–semi–IPN<\div>

۲Study on Polyurethane Elastomeric network based on polybutadiene–ol\polypropyleneoxide mixture: The Structure–Mechanical and Thermal Properties relationship
نویسنده(ها): ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۱۲
Polyurethane elastomer networks were synthesized based on hydroxyl terminated polybutadiene\polypropyleneoxide (HTPB\PPO) mixtures, 2,4–toluene diisocyanate and 1,4– butanediol. Various networks with different molar ratio of HTPB to PPO (0\100, 25\75, 50\50, 75\25 and 100\0) had been prepared. Depending on the length of soft segment, average functionality of polyol mixtures, mechanical and thermal properties of samples were varied. Ourobservations confirmed that final properties of the networks can be attributed to two synergistic factors: (a) formation of chemical network (crosslinking) and (b) soft segment length. An optimum composition was found. This optimum composition shows that both physical (hard domains) andchemical network (crosslinking) have synergistic effects. Synthesized polyurethane elastomer networks have a structure similar to semi interpenetrating polymer networks, which is namedpseudo–semi–IPN. These novel polyurethane elastomer networks show higher tensile strength and economic benefit than polyurethanes which are based on other non–polar polyols.<\div>
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