2011 YÜksek lisans tez özetleri

Investıgatıons Of Degradatıon Kınetıcs Of Varıous Commercıal Plastıcs Wıth Thermogravımetrıc Analysıs Method

In this study, thermal oxidative degradation kinetics of various commercial plastics, which have different characteristics such as polyethylene (PE), poly(ethylene terephthalate) (PET) and polystyrene (PS), have been investigated with Thermogravimetric Analysis (TGA).

To this purpose, various commercial plastics which provided from different firms such as low-density polyethylene (LDPE), medium density polyethylene (MDPE), high-density polyethylene (HDPE), starch based polyethylene (BİOPE) and post-consumer waste plastics such as PE tube, PET bottle and PS cup were used.

Thermal oxidative degradation experiments were carried out in “Linseis, STA PT 1750”. Experiments were conducted in dynamic condition at different heating rates of 10, 20, 30 and 40^oC min^-1. Constant heating rates were used between 25 and 650^oC. Air flow rate was maintained at 0.1 L min^-1 and sample weights were approximately 10 mg in all runs. Then thermal behaviors of plastic materials have been determined.

Degradation behaviors of the selected commercial plastics were tested with different heating rates and the degradation temperatures of the plastics were compared. Degradation behaviors of pure and waste plastics were examined by comparing with each other. The activation energy of the degradation processes were also calculated with the Kissinger Flynn-Wall-Ozawa and Coats-Redfern models. In addition, the influence of molecular weight and presence or absence of additive in polymer structure on the degradation behavior was also discussed. All three models, which can apply to calculate the thermal degradation reaction parameters, are also suitable for selected plastic materials.

According to the results, the average activation energy of the commercial polyethylene samples with different characteristics was determined as 132 kJ mol^-1. Activation energy of starch based biodegradable PE sample was also determined as 104 kJ mol^-1. At the end of the kinetic calculations for waste PE pipe, waste PET bottle and waste PS cup, the average activation energies were calculated as 136, 130 and 45 kJ mol^-1, respectively.

  

KURDAŞ İpek

Danışman : Yard. Doç. Dr. Metin HASDEMİR

Anabilim Dalı : Kimya Mühendisliği

Programı : Temel İşlemler ve Termodinamik

Mezuniyet Yılı : 2011

Tez Savunma Jürisi : Yard. Doç. Dr. Metin HASDEMİR

Prof. Dr. Umur DRAMUR

Prof. Dr. İsmail KIRBAŞLAR

Doç. Dr. İsmail İNCİ

Prof. Dr. Mehmet MAHRAMANLIOĞLU