FT-IR,XRD,Raman tekniklerini kullanarak sıcaklık değişikliğine bağlı olarak polipropilen filmlerinde kristallinite ve yönteminin incelenmesi

ABSTRACTINVESTIGATION OF THE CRYSTALLINITY AND ORIENTATION OFPOLYPROPYLENE WITH RESPECT TO TEMPERATURE CHANGESUSING FT-IR, XRD, AND RAMAN TECHNIQUESHARUN NEZİH TÜRKÇÜM.S. in ChemistrySupervisor: Prof.Dr. Şefik SüzerAugust 2004Having good mechanical and barrier properties, polypropylene films are widely usedin food-packing industry. The relation of crystallinity and orientation ofpolypropylene with these properties are well known. Temperature increase has animportant effect on the crystallinity and orientation of polypropylene. The purpose ofthis study is to understand better crystallinity and orientation changes of the cast andbi-axially oriented polypropylene films with respect to temperature effect. Thesechanges were investigated using especially in-situ FT-IR and dichroism as well asXRD and Raman spectroscopy.For this purpose, an in-situ variable temperature set-up is developed and adapted forFT-IR studies. Accordingly, the changes in the peaks related to the amorphous andcrystalline contents of the films as well as the peaks reflecting the orientation of thefilms were investigated over the temperature range from 120-170oC. Temperaturecycle was also applied. Moreover, the films were investigated after application ofadditional stress at 120oC for various durations.The crystallinity and orientation of the films are affected significantly when the filmswere analyzed at higher temperature (>150oC). The crystallinity content of the filmIIIrecovers after returning back to room temperature whereas orientational loss arepermenant.Keywords: Polypropylene, FT-IR, Dichroism, XRD, Raman Spectroscopy,Phase Transition, and Temperature EffectIV