Halloysit Nanotüp Takviyeli Kopoliester Termoplastik Elastomer Kompozitler: Isıl ve Mekanik Özelliklerin İncelenmesi

Öz

Nano dolgular polimerlerin ısıl ve mekanik özelliklerini geliştirmek için sıklıkla kullanılan malzemelerdir. Halloysit (HNT) içi boş tüp şeklinde doğal bir alümina silikat nano dolgudur. Bu çalışmada, termoplastik elastomer ailesinin bir üyesi olan kopoliester (COPE) polimerinin ısıl ve mekanik özellikleri organofilik yüzey modifikasyonu yapılmış HNT (Org-HNT) dolgusu ile geliştirilmeye çalışılmıştır. Değişik oranlarda (3,5 ve 7 phr) Org-HNT içeren kompozitler bir dahili karıştırıcı yardımıyla eriyik harmanlama metodu ile hazırlanmıştır. Elde edilen kompozitlerin morfolojik, reolojik, ısıl ve mekanik karakterizasyonları saf COPE ile karşılaştırmalı olarak incelenmiştir. Taramalı elektron mikroskobu (SEM) analizi, 3 ve 5 phr Org-HNT içeren kompozitlerin matris içinde göreceli daha homojen ve ince bir dağılım sergilediğini, 7 phr Org-HNT kullanıldığında ise nanotüplerin agregat şeklinde kaldığını göstermiştir. Org-HNT varlığında COPE’nin erime sıcaklığı artma eğilimi göstermiş ve bununla birlikte nanotüplerin nükleasyon ajanı etkisi ile kristalizasyon sıcaklığı yaklaşık 8°C artmıştır. Kompozitlerin elastik modül değerleri ve Shore sertlikleri Org-HNT miktarının artması ile doğru orantılı olarak artarak, 7 phr Org-HNT içeren kompozitte saf COPE ile karşılaştırıldığında yaklaşık %55’lik modül artışı bulunmuştur. COPE’nin başlangıç bozunma sıcaklıkları Org-HNT’lerin iyi dağılım gösterdiği 3 ve 5 phr kompozitlerinde gelişme gösterirken 7 phr kompozitinde azalmıştır. Bununla birlikte bütün kompozitlerin maksimum bozunma hızları saf COPE’den daha düşük değerler almıştır.

Anahtar Kelimeler

• COPE
• halloysit
• ısıl-mekanik özellikler

Halloysite Nanotube Reinforced Copolyester Thermoplastic Elastomer Composites: Examination of Thermal and Mechanical Properties

Öz

Nano fillers are frequently used materials to improve the thermal and mechanical properties of polymers. Halloysite (HNT) is a natural alumina silicate nano filler that has the form of a hollow tube. In this study, the thermal and mechanical properties of the copolyester (COPE) polymer which is a member of the thermoplastic elastomer family, was tried to be improved with using organophilic surface modified HNT (Org-HNT) filler. Composites containing Org-HNT in different proportions (3,5 and 7 phr) were prepared by melt blending method with help of an internal mixer. Morphological, rheological, thermal and mechanical characterizations of the composites were examined in comparison with pure COPE. Scanning electron microscopy (SEM) analysis showed that composites containing 3 and 5 phr Org-HNT exhibit a relatively more homogeneous and fine distribution in the matrix, and nanotubes remain aggregated when using 7 phr Org-HNT. In the presence of Org-HNT, the melting temperature of the COPE tended to increase and the crystallization temperature of the increased by about 8 ° C with the effect of the nucleation agent effect of nanotubes. The elastic modulus and Shore hardness values of the composites increased with increasing amount of Org-HNT, and a increment of % 55 in modulus was found with the composite containing 7 phr Org-HNT compared to pure COPE. Initial decomposition temperature of the COPE increased with using 3 and 5 phr HNT due to Org-HNTs showed good distribution in these composites. On the other hand, the all composites exhibited lower maximum degradation rates in comparison to pure COPE.

Anahtar Kelimeler

• COPE
• halloysite
• thermal and mechanical properties

Kaynakça

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