Yıldız-Şekilli Poli(L-Laktik Asit) Nanokompozitlerin Yerinde Polimerizasyon Yöntemiyle Hazırlanması ve İncelenmesi

Year 2020, , 631 - 642, 31.08.2020

Naile Karakehya , Ceyda Bilgiç

https://doi.org/10.18185/erzifbed.699409

Abstract

Poli(L-laktik asit) (PLLA) bir diğer adıyla poli(L-laktit), yenilenebilir kaynaklardan üretilen biyobozunur termoplastik bir polimerdir. Bu çalışmada çeşitli nano-dolgu maddeleri kullanılarak in-situ (yerinde) polimerizasyon yöntemi ile üç farklı PLLA nanokompozit hazırlanmıştır. Poli(L-laktik asit), L-laktit halka açılma polimerizasyonu ile elde edilmiştir. Başlatıcı olarak pentaeritritol, katalizör olarak kalay-2-etilheksanoat (Sn(Oct)2) kullanılarak yıldız-şekilli PLLA sentezlenmiştir. Dolgu maddeleri sisteme katalizör ekleme aşamasında katılmıştır. Kullanılan nano-seviyedeki dolgu maddeleri nanokristal selüloz (NCC), organo-montmorillonit (OMMT) ve çok duvarlı karbon nanotüptür (CNT). Ağırlıkça %2 dolgu maddesi içeren nanokompozitlerin ısıl özellikleri termogravimetrik analiz (TGA) ile incelenmiştir. Yüzde 5 ve yüzde 50 ağırlık kaybı ve maksimum ağırlık kaybı sıcaklıkları ve 500 °C’deki çar miktarı belirlenmiştir. Ayrıca hazırlanan nanokompozitlerin kristal yapısı X-ışını kırınım (XRD) yöntemiyle incelenmiştir. Bu çalışmada elde edilen saf PLLA’in ısıl bozunma sıcaklık aralığı 250-300 °C’dir ve bozunma iki adımda gerçekleşmektedir. Saf PLLA ve PLLA nanokompozitler 220 °C’ye kadar ısıl kararlılıklarını korumaktadırlar.

Keywords

poli(laktik asit), yerinde polimerizasyon, nanokompozit, XRD, TGA

Supporting Institution

Eskişehir Osmangazi Üniversitesi

Project Number

201544004, 2015-555

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