کوپلیمریزاسیون‌ رادیکالی کنترل‌شده/ زنده استایرن و متیل‌متاکریلات در محیط پراکنده آبی: سنتز و شناسایی نانوکامپوزیت‌

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشکده شیمی، پردیس علوم، دانشگاه تهران، تهران

2 دانشکده مهندسی پلیمر و رنگ، دانشگاه صنعتی امیرکبیر، تهران

3 دانشکده مهندسی پلیمر، دانشگاه صنعتی سهند، تبریز

چکیده

لاتکس پایدار نانوکامپوزیت کوپلیمر (استایرن- متیل متاکریلات)/ خاک رس به روش پلیمریزاسیون رادیکالی انتقال اتم معکوس در سیستم مینی‌امولسیونی و در دمای C° 90 سنتز شد. پلیمریزاسیون مینی‌امولسیونی به جهت فواید فراوان آن در کپسوله کردن مواد معدنی، سهولت فرآیند هسته‌زایی، و حذف حلال‌های آلی مورد استفاده قرار گرفت. درجه تبدیل نهایی مونومر با استفاده از روش وزن‌سنجی اندازه‌گیری شد. توزیع اندازه قطرات و ذرات نیز با استفاده از روش تفرق دینامیکی نور (DLS) به‌دست آمد. همچنین متوسط عددی وزنی و وزن مولکولی و شاخص پراکندگی با استفاده از روش کروماتوگرافی ژل تراوایی (GPC) مورد ارزیابی قرار گرفت. توزیع وزن مولکولی در مورد نمونه‌های نانوکامپوزیتی پهن‌تر بوده و با افزایش میزان نانوذره نیز پهن‌تر گردید. درصد مولی و میزان تبدیل هر یک از مونومرها در زنجیرهای کوپلیمری با استفاده از روش طیف‌سنجی رزونانس مغناطیسی هسته (1H NMR) تخمین زده شد. نتایج تفرق اشعه ایکس (XRD) نشان‌دهنده ساختار پراکنشی تمامی نانوکامپوزیت‌های سنتزی به روش پلیمریزاسیون درجا بود. نتایج FTIR نشان‌دهنده قرار‌گیری موفق ذرات نانو در ماتریس پلیمری است. تصاویر SEM نیز توزیع یکنواخت ذرات کروی نانوکامپوریت کوپلیمر (استایرن- متیل متاکریلات)/ خاک رس با محدوده اندازه nm 200  را نشان می‌دهد.
 
 

کلیدواژه‌ها


عنوان مقاله [English]

Controlled/Living Radical Copolymerization of Styrene and Methyl Methacrylate in Aqueous Dispersed Media: Synthesis and Characterization of Nanocomposite

نویسندگان [English]

  • KhezroALLAH Khezri 1
  • Vahid Haddai Asl 2
  • Hossein Roghani-Mamaqani 3
1 School of Chemistry, University College of Science, University of Tehran, Tehran
2 Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran
3 Department of Polymer Engineering, Sahand University of Technology, Tabriz
چکیده [English]

Stable latexes of poly (styrene-co-methyl methacrylate)/clay nanocomposites were synthesized by in-situ reverse atom transfer radical polymerization at 90 °C and in miniemulsion system. Miniemulsion polymerization has been employed for its abundant advantages to encapsulate inorganic materials, simple nucleation step, and elimination of organic solvents. Final monomer conversion was determined by gravimetric method. Droplets and particles size distribution were obtained by using dynamic light scattering (DLS) analysis. Also, number and weight average molecular weight and polydispersity indexes of the samples were also evaluated by GPC method. In addition, the PDI value of the neat polymer was smaller than the extracted polymer from nanocomposites and in the case of nanocomposites it increased by increasing nanoclay content. Mole ration and fractional conversion of each monomer in copolymer chains were estimated by using 1H NMR spectroscopy. XRD patterns displayed no peak in in-situ synthesized nanocomposites which indicates an exfoliated structure of all the nanocomposites prepared by this method. FTIR spectra indicate successfully loading of nanoclay in the copolymer matrix. SEM micrographs presented a monodisperse distribution of spherical shape particles of poly (styrene-co-methyl methacrylate)/clay nanocomposite with a size in the range of around 200 nm.

کلیدواژه‌ها [English]

  • Poly (styrene-co-methyl methacrylate)
  • Nanocomposite
  • RATRP
  • Miniemulsion Polymerization
  • Nanoclay
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