Kompozit malzeme üretiminde kullanılan poliesterlerin mekanik, termal ve kimyasal özelliklerine başlatıcı etkisinin incelenmesi.

Unsaturated polyester (UP) resins, used as a matrix material in polymer based composite, has been extensively utilized in industry due to the fact that revealing high mechanical properties, rapid curing, endurance against chemical substances and physical conditions. Determination of the optimum ratio of inititator (curing agent), requiring for polymerization process is of great importance for the production of composite material having desirable mechanical properties. For this purpose, the physical, chemical, thermal and mechanical properties of the polyesters used in the production of composite materials were investigated by using initiators at different ratios. In scope of the study, orthophtalic and isophtalic resins (polymer based resin) were used as a resin. During polymerization procees, methyl ethyl keton peroxide (MEKP) has been used as initiator (curing agent) with different the ratio; 1%, 1.5%, 2% ve 2.5%. Cobalt octaoate (C16H30CoO4) was added as catalyst (accelarating) in the rate of 1% to increase curing rate and yield of polymerization. To determine physical parameters, gelation temperature, gelation time, peak exotherm temperature and viscosity analysis were carried out. Thermogravimetric analyzes (TGA) were performed to determine thermal stability. Fourier transform Infrared Spectroscopy (FT-IR) was used to investigate the molecular interaction in the end of the polymerization. Mechanical properties (tensile strength, elastic modulus, flexture strength and flexture modulus) were determined with the Universal Test Machine. The initiator and resin ratio which have optimum parameters and performance were determined by evaluating the results obtained from experimental studies. As a result, the mechanical properties of the unsaturated polyester resin were changed based on initiator ratio. When the relation between initiator ratio and the mechanical properties is examined, mechanical strengths of the composites which composed of the isophthalic resin generally have higher than the composites composed of the orthophtalic resin. Optimum initiator ratio for mechanical strength values were determined as 1% for the composite obtained from both isophtalic and orthophtalic resins. [ABSTRACT FROM AUTHOR]