Mehdi Nekoomanesh
Iran Polymer and Petrochemical Institute, Tehran, Iran
[ 1 ] - Effect of NH3/methylaluminoxane/dodecylamine modifiednanoclay on morphology and properties of polyethylene/ clay nanocomposites prepared by in-situ polymerization
This study presents methods for treating a kind of nanoclay and investigates the effects of methylaluminoxane (MAO) exposure time and or dodecylamine (DDA) reflux time on in-situ polymerization of ethylene in the presence of nanoclay and examines the morphology and properties of the prepared polyethylene/clay nanocomposites. The results revealed that by increasing MAO exposure time productivity...
[ 2 ] - Effects of FeCl3 doping on the performance of MgCl2/TiCl4/DNPB catalyst in 1-hexene polymerization
The aim of this study was to examine the effect of catalyst doping on the performance of MgCl2. EtOH/TiCl4 catalyst system. In this regard, a series of undoped as well as FeCl3-doped catalysts was prepared and employed in 1-hexene polymerization. A modified catalyst containing 10 wt. % of FeCl3 dopant demonstrated the highest activity, with 32% activity increase compared to unmodified one, amon...
[ 3 ] - Polyolefin and olefin production in Iran: Current and future capacities
Due to easy availability of cheaper raw material and increase in new applications, the use of polyolefins in various industries is becoming a major priority. The Middle East region, on account of its vast oil and gas reserves has, in the last decade or so, been developing many new petrochemical complexes with their expansion into colossal polyolefin production capacities. The predictions are th...
[ 4 ] - Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization
Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2 metallocene catalysts using triethylaluminum (TEA) as coupling agent. Response surface methodology (RSM) is used to evaluate the interactive effects of different parameters including amounts of metallocene and TEA and temperature on metallocene loading. Analyzing the amounts of Al...
[ 5 ] - Estimation of pyrolysis product of LDPE degradation using different process parameters in a stirred reactor
Pyrolysis of low density polyethylene (LDPE) by equilibrium fluid catalytic cracking (FCC) was studied in a stirred reactor under different process parameters. In this work, the effect of process parameters such as degradation temperature (420-510°C), catalyst/polymer ratio (0-60%), carrier gas type (H2, N2, ethylene, propylene, Ar and He), residence time and agitator speed (0-300 rpm) on the c...
[ 6 ] - The role of 1-hexene comonomer content in thermal behavior of medium density polyethylene (MDPE) synthesized using Phillips catalyst
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...
[ 7 ] - Storage time effect on dynamic structure of MgCl2.nEtOH adducts in heterogeneous Ziegler-Natta catalysts
Primary MgCl2.3.3EtOH adduct (PCT1) was prepared by melt quenching method and then submitted into a programmed thermal dealcoholation project using a fluidized bed reactor. During thermal dealcoholation program, different MgCl2.nEtOH support samples with n= 3.0, 2.7, 2.4, and 2.1 were selected and named as PCT2 to PCT5, respectively. Structural analysis of the support samples showed a significa...
[ 8 ] - مروری بر کامپوزیت‌های پلیمر-سیلسزکیوکسان اولیگومری چندوجهی
در سال‌های اخیر، کامپوزیت‌های پلیمری با نانوذرات سیلسزکیوکسان اولیگومری چندوجهی (POSS) بسیار مطالعه شده‌اند. ابعاد نانومتری و نیز امکان وجود گروه‌های عاملی مختلف در ساختار این نانوذرات باعث شده است تا کامپوزیت‌های ساخته شده از آن‌ها، دارای خواص منحصربه فردی باشند که در مواد هیبریدی متداول مشاهده نمی‌شود. اندازه ذرات POSS در حدود nm 1 تا nm 3 است. این ذرات ساختاری صلب دارند و می‌توانند به طور ...
[ 9 ] - پلی‌اولفین‌های عامل‌دار: از سنتز تا کاربرد
آلیاژکردن پلیمرها، کوپلیمرکردن، ایجاد گروه‌های عاملی متنوع، تهیه کامپوزیت پلیمرها و اجزای معدنی یا افزودن مواد افزودنی، مانند نرم‌کننده‌ها و پایدارکننده‌ها به پلیمرها، از روش‌های نوین اصلاح خواص پلیمرها و ایجاد کاربردهای جدید برای آن‌هاست. در این میان، عامل‌دارکردن پلی‌اولفین‌ها روشی مفید برای سنتز مواد جدید با کاربردهای متنوع است. زیرا گروه‌های عاملی خواص مهم پلیمر، مانند چسبندگی، نفوذپذیری، ا...
[ 10 ] - اثر اصلاح کنند ه ها روی فعالیت کاتالیزورهای زیگلر-ناتا و خواص نهایی پلیمر در پلیمرشدن اولفین ها
فعالیت کاتالیزور از مهم ترین پارامترها در فرایندهای پلیمرشدن است. برای یک سامانه کاتالیزوریفعالیت ممکن است به شرایط پلیمرشدن از قبیل دما و فشار وابسته باشد. با این حال، برای شرایط ثابتپلیمرشدن، افزایش فعالیت به روش تغییر دما و فشار رضایت بخش نیست و صنعتگران مجبورند تا مقدارکاتالیزور در راکتور یا زمان انجام پلیمرشدن را افزایش دهند که این کار نیز از لحاظ اقتصادی مقرونبه صرفه نیست. در سال های اخیر...
[ 11 ] - مروری بر نسل های گوناگون کاتالیست های زیگلر ـ ناتا و اجزای تشکیل دهنده آن ها برای پلیمریزاسیون پروپیلن
کشف پلیمریزاسیون اولفین ها با کاتالیست های فلزهای واسطه در اوایل دهه ی1950میلادی توسط زیگلر و ناتا از اهمیت به سزایی برخوردار بود و آغازی برای تولید پلی اولفین های صنعتی بود.این کاتالیست ها طی بیش از 60 سال گذشته رشد چشمگیری داشته اند و امروزه به عنوان کاتالیست هایی مؤثر برای انواع پلیمریزاسیون اولفین ها استفاده می شوند. برای تولید پلی پروپیلن ایزوتا...
[ 12 ] - Effect of temperature, heating rate and zeolite-based catalysts on the pyrolysis of high impact polystyrene (HIPS) waste to produce fuel-like products
Pyrolysis of high impact polystyrene (HIPS) waste has been investigated under different process parameters, such as temperature, heating rate and types of zeolitic catalysts to produce valuable liquid products. Liquid, gas and coke as products of pyrolysis and aromatic, naphthene, olefin and paraffin as liquid components were obtained and their molecular weight distributions were studied with c...
[ 13 ] - Thermal behavior of ethylene/1-octene copolymer fractions at high temperatures: Effect of hexyl branch content
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...
[ 14 ] - The relationship among changes in microstructure, active sites behavior and properties in the propylene polymerization with a 4th generation Ziegler-Natta catalyst
Three polypropylene samples (1-3) were synthesized with a 4th generation Ziegler-Natta catalyst in the presence of cyclohexyldimethoxymethylsilane (donor c), dicyclopenthyldimethoxysilane (donor d) and diisopropyldimethoxysilane (donor p), respectively, as external electron donors. The physical properties of the synthesized polypropylenes were determined. For samples 1 to 3, Successive self-nuc...
[ 15 ] - Competitive particle growth at different conditions of oligo-micelle formation in hydro-alcoholic solution of anionic double-chain emulsifier via batch emulsion polymerization of vinyl chloride
The condition of oligo-micelle formation of sodium di-isodecyl sulfosuccinate (SDIDS) emulsifier in hydroalcoholic solutions is used to study particle formation of vinyl chloride emulsion polymerization in a batch reactor. The change on micellization behavior was investigated by critical micelle concentration (CMC) and zeta potential parameters. To detect the occurrence of secondary nucleation ...
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