مطالعۀ تجربی بر روی خواص مکانیکی لاستیک‌های بازیافت‌شده از راه فناوری مکانیکی

نوع مقاله : مقاله پژوهشی

نویسندگان

فردوسی مشهد

چکیده

بازیافت پسمانده‌های لاستیکی به‌دلیل مشکلات زیست محیطی و همچنین افزایش قیمت لاستیک نو رو به فزونی دارد. از آنجا که لاستیک EPDM پایۀ پلیمری بسیاری از قطعات لاستیکی اتومبیل (به‌جز تایرها) می‌باشد، ضرورت بازیافت و برگشت به چرخۀ تولید ضایعات مربوطه ضروری به‌نظر می‌رسد. در این پژوهش فناوری مکانیکیِ بازیافت مبتنی بر دستگاه اکسترودرِ دوپیچه به‌همراه واولکانش ضایعات لاستیکی اتومبیل بر پایۀ EPDM مورد استفاده قرار گرفت. سپس لاستیک‌های واولکانیده دریک سیستم نیمه‌کارآمد، پخته شد و ویژگی‌های پخت و خواص مکانیکی آن‌ها شامل سختی، استحکام کششی و ازیاد طول تا پارگی مقایسه و نتایج بحث شد. نتایج به‌دست آمده نشان داد که واولکانش لاستیک ضایعاتی با راندمان بالایی انجام گرفته است. همچنین میان افزایش درصد واولکانش و کاهش چگالی اتصالات عرضی از یک‌سو و بهبود ویژگی‌های پخت و خواص مکانیکی آمیزه‌های ولکانش مجددشده از سوی دیگر رابطۀ مستقیمی مشاهده گردید. شرایط بهینه برای واولکانش در اکسترودر دوپیچه برمبنای نتایج طراحی آزمایش سرعت پیچ اصلی ۱۸۰ دور در دقیقه در دمای ۲۲۰ درجه سانتیگراد تعیین شد. متغیر بودن ترکیب مواد اولیه به‌دلیل جمع­آوری ضایعات از منابع مختلف جنبۀ عملی و کاربردی پروژه را به چالش می‌کشد.

کلیدواژه‌ها


عنوان مقاله [English]

The Study on the Mechanical Properties of the De-Vulcanized Waste Rubber by a Mechanical Technique

نویسندگان [English]

  • Saeed Ostad Movahed
  • Sakineh Karbalaei Nezhad
  • Bahareh Babakhani
Ferdowsi university of Mashhad
چکیده [English]

Recycling of waste rubbers is developing due to environmental concerns and continuous increasing raw materials price. The EPDM (ethylene-propylene-diene rubber) rubber is the rubber base of the non tire automotive rubber articles and their recycling is necessary for resources saving and the environment protection. A mechanical recycling technique, a twin screw extruder with the aid of a de-vulcanizing agent, TMTD (tetramethylthiuram disulfide) was used to de-vulcanize waste rubber powder from discarded EPDM automotive parts. The de-vulcanized rubbers, subsequently, re-vulcanized in a semi-efficient (SEV) curing system and correspondent curing and mechanical properties including hardness, tensile strength and elongation at break were measured and the results were compared and discussed. The results showed that the waste rubber de-vulcanized with used technique efficiently. The direct relationship was observed between increasing de-vulcanization percent and also the crosslink density reduction of the waste cured rubbers with improving the curing and mechanical properties of re-vulcanized compounds. The optimum de-vulcanization operating conditions were obtained by a design of experiment software at rotor speed of 180 rpm at a constant operative temperature, 220 . The main challenge for using the outcomes of this study in commercial scale was the difference between waste rubbers composition because they provided from various sources.  

کلیدواژه‌ها [English]

  • recycling
  • EPDM rubber
  • Twin screw extruder
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