Study On Transamidation In Melt Blending Process Of PA66 And PA9T

Polyamide(PA)is the most widely used engineering plastic.At present,high-performance polyamides have important applications in aerospace and defense industries.However,there are great differences in processability and heat-resistance of different types of polyamide during the application of polyamide materials.In order to reduce the cost and improving the performance of polyamide,it's a common method to blend different kinds of polyamide.In recent years,semi-aromatic polyamides have attracted more and more attention because of the excellent processing property of aliphatic polyamides and the good heat resistance of full aromatic polyamides.The melting temperature of semi-aromatic polyamide is higher than the decomposition temperature,which is difficult to process,so aliphatic polyamide needs to be mixed to improve the processing.However,during blending,the amide bond will be opened and rearranged to exchange due to the influence of high temperature and mechanical field,which changes the compatibility,crystallinity and heat resistance of materials,thus affecting the product performance.Transamidation is ubiquitous in polyamide materials,so it is of great significance to study the reaction in industrial production.PA66 has the largest yield and the widest application among the five engineering plastics;PA9T has excellent strength and toughness and is easy to process.Therefore,this project uses PA66 and PA9 T as raw materials to study transamidation,and the research content is as follows:1.The processing factors affecting the transamidation were mainly studied from the ratio of raw materials,processing temperature and processing time.NMR(nuclear magnetic resonance spectroscopy),FTIR(Fourier transform infrared spectroscopy),TGA(thermogravimetric analyzer),DSC(differential scanning calorimeter),GPC(gel permeation chromatography)and other means were used to characterize the transamidation.2.Triaza dicyclodecene(TBD)and sodium acetate(YSN)were used to investigate the mechanism of action and inhibitory ability of the two inhibitors in the process of transamidation.In addition,the catalyst for toluene sulfonic acid(pTsOH)was used to accelerate transamidation,and the inhibition effect was compared with that of inhibitors to highlight the role of inhibitors.