Effects Of Carbon Deposited Film On The Crystalline Phase Transformation And Melting Behavior Of Poly(butylene Adipate)

In the present study,the effects of the crystallization behavior,melting behavior and its crystalline phase transformation of poly(butylene adipate)were studied by temperature-modulated differential scanning calorimetry(TMDSC),polarized optical microscopy(POM)and Fourier infrared spectrometer(FTIR).The research shows that the carbon film by vacuum evaporation can improve the crystallization ability of film.The results of DSC test showed that the crystallization temperature of PBA was changed with the evaporation of carbon film,so that it could crystallize at higher temperature.After that,the PBA thin films were evaporated with carbon coating and observed under polarized optical microscopy(POM).It was found that during the crystallization process,the carbon film could enhance the nucleating ability of PBA.In the process of gradual cooling of PBA from the melting process,the carbon film can produce crystal nuclei at a higher temperature,and the number of nuclei appearing at the same temperature is much more than that without carbon film.Furthermore,the Fourier infrarea spectrometer was usea to cnaracierize the ?-PBA and ?-PBA samples before and after the vacuum evaporation of carbon films,and the infrared curves were obtained at different crystallize temperatures.The experimental results show that the melting recrystallization of the ?-PBA samples after the vacuum evaporation of the carbon film need crystal at 35°C and its above temperature to obtain pure a crystal phase compared to the?-PBA sample without the evaporation of carbon film.After the vacuum evaporation of the carbon film of the ?-PBA sample,the melting recrystallization can form a pure a crystal PBA above 25 °C.This shows that the carbon film has a certain fixed effect on the molecular chain of PBA,thus maintaining the order of its crystalline molecular chain,so that it can be more changed during the crystallization process to form the specific crystal before its fixation.In addition,the study shows that the vacuum evaporation of carbon film on the surface of PBA film has a significant effect on its crystalline transformation and melting behavior.We know that the(3 crystal of PBA turns to a crystal at a certain temperature Ta(Ta>Tc).We use the differential scanning calorimeter(DSC)and polarizing microscope(POM)to characterize the melting curve of PBA before and after carbon evaporation.The results show that the evaporation of carbon films can improve the melting temperature of PBA crystals and make the thermodynamics more stable.Fourier transform infrared(FTIR)was used to characterize the transformation behavior of PBA at high temperature.It was found that carbon film inhibited the transformation of crystal form.