تهیه لاتکس‌های یکنواخت نانوکامپوزیت پلی‌استایرن/خاک رس به روش پلیمریزاسیون رادیکالی انتقال اتم معکوس درجا در سیستم مینی‌امولسیون

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشگاه صنعتی امیرکبیر، گروه مستقل شیمی

2 دانشگاه صنعتی امیرکبیر، دانشکده مهندسی پلیمر و رنگ

3 دانشگاه صنعتی سهند، دانشکده مهندسی پلیمر

چکیده

لاتکس‌های پلی‌استایرن با پراکنش نانو صفحات خاک رس به وسیله پلیمریزاسیون رادیکالی انتقال اتم معکوس درجا در سیستم مینی‌امولسیون و در دمای C° 90 سنتز شدند. درجه تبدیل نهایی مونومر با استفاده از روش وزن‌سنجی اندازه‌گیری شد. توزیع اندازه قطرات و ذرات نیز با استفاده از روش تفرق نور (DLS) به دست آمد. همچنین متوسط عددی و وزنی وزن مولکولی و شاخص پراکندگی با استفاده از روش کروماتوگرافی ژل تراوایی (GPC) مورد ارزیابی قرار گرفت. مقدار شاخص پراکندگی پلی‌استایرن خالص در مقایسه با مقادیر به دست آمده از نمونه‌های نانوکامپوزیتی پایین‌تر بود که با افزایش میزان نانوذره، افزایش یافت. نتایج تفرق اشعه ایکس (XRD) نشان می‌دهد که صفحات خاک رس در ماتریس پلیمری پراکنده شده و نانوکامپوزیت‌هایی با ساختار پراکنشی حاصل گردیده است. تشکیل موفقیت‌آمیز زنجیره‌های پلی‌استایرن و ماهیت زنده این زنجیره‌ها توسط نتایج FTIR به اثبات رسید. نتایج حاصل از HNMR نیز حاکی از ماهیت زنده فرآیند پلیمریزاسیون است. تصویر SEM نیز توزیع یکنواخت ذرات کروی نانوکامپوریت پلی‌استایرن با اندازه ذرات حدود nm 200 را در نمونه نانوکامپوزیتی محتوی 1% خاک رس نشان می‌دهد.

کلیدواژه‌ها


عنوان مقاله [English]

Preparation of Monodisperse Polystyrene/Clay Nanocomposite Latexes via In Situ Reverse Atom Transfer Radical Polymerization in a Miniemulsion System

نویسندگان [English]

  • Khezrollah Khezri 1
  • Vahid Haddadi Asl 2
  • Hossein Roghani Mamaqani 2
  • Mehdi Salami Kalajahi 3
1 Department of Chemistry, Amirkabir University of Technology
2 Department of Polymer Engineering and Color Technology, Amirkabir University of Technology
3 Department of Polymer Engineering, Sahand University of Technology
چکیده [English]

Polystyrene latexes with dispersion of nanoclay layers were synthesized by using in situ miniemulsion reverse atom transfer radical polymerization at 90 °C. Final monomer conversion was determined by employing gravimetric method and droplet and particle size distributions were obtained by using dynamic light scattering (DLS) analysis. Also, the number- and weight- average molecular weight and polydispersity index of the nanocomposites were evaluated by using GPC. It was found out that the PDI value of the neat polystyrene is lower than that of the polystyrene chains extracted from the nanocomposites; PDI rose by increasing nanoclay content in the polymer matrix. The XRD results indicated that clay layers were dispersed in the polystyrene matrix and therefore exfoliated nanocomposites were formed. The successful formation of polystyrene chains and their living nature were demonstrated by FTIR spectra. The living nature of the polymerization was also confirmed by the HNMR results. The SEM micrograph presents the monodisperse distribution of spherical particles with sizes in the range of around 200 nm in the nanocomposite containing 1 wt% of nanoclay

کلیدواژه‌ها [English]

  • RATRP
  • Polystyrene
  • Nanocomposite
  • Miniemulsion
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