| The chemical structure and reaction mechanism have an important impact on the various properties of polymer materials.The characterization of the reaction mechanism of polymer materials has always been a necessary task in the research and development,performance evaluation,and understanding of the relationship between structure and performance of polymer materials.In situ infrared spectroscopy is one of the effective characterization methods,but it has the drawbacks of long research cycles and high machine time occupancy.We have developed a multi-channel in-situ reaction device on the basis of in-situ infrared spectroscopy.Combining this device with an infrared spectrometer,we can monitor the infrared spectra of several groups of samples at different temperatures.This device has the characteristics of high efficiency and good repeatability,which can make up for the shortcomings of in-situ infrared spectroscopy in studying reaction kinetics and mechanism.This article is based on multi-channel in situ infrared spectroscopy technology to conduct in situ characterization of two types of polymer materials during aging and curing processes.Combined with a constant temperature kinetic model,to explain the aging and curing behavior of two experimental materials from both chemical structure and apparent activation energy,and to explain the relationship between kinetics,conversion,and time and activation energy.The main research content is divided into the following three parts:（1）The change of chemical structure of polyvinyl butyral（PVB）during thermal aging was explored by multi-channel in-situ infrared spectroscopy.The activation energy（Ea）values of characteristic functional groups-OH,-CH3,-C=O and-C-O were calculated by combining zero-order reaction and first-order reaction kinetic models,and the thermal aging mechanism of PVB was proposed.（2）The characterization method of multi-channel in situ infrared spectroscopy was used to monitor the isothermal in situ infrared spectroscopy of two epoxy resin curing systems,AFG-90 and MNA,711 and MNA.Combined with the isothermal kinetic model,the curing behavior of the system was explained from two aspects:chemical structure and apparent activation energy.The functional relationship between the curing kinetics,conversion rate,curing state,time and activation energy of AFG-90 and 711 epoxy systems was explained.（3）The chemical structure changes of the thermal aging process of AFG-90 and MNA epoxy resin system were monitored by multi-channel in-situ infrared spectroscopy,and the mechanical and thermal properties were tested by nanoindentation test and DSC differential scanning calorimetry.The relationship between the chemical structure and properties of epoxy resin aging was explored.In this paper,application of multi-channel in-situ infrared spectroscopy in thermal aging,curing,and structural and performance analysis of materials.This indicates that multi-channel in-situ infrared spectroscopy technology is an effective experimental method for studying reaction kinetics and mechanisms. |
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