| Since 21 st century,the research and application of itaconic acid had attracted the attention of researchers.Itaconic acid,which applied in papermaking,fire retardant and mothproofing agent,was studied at home and abroad.With the development of the localization of itaconic acid,its applications would be expanded and developed.At present,the application of itaconic acid was mainly used in sulfonation,addition and halogenation because of the molecular structure of the double bond,or reacted with other monomers(polyol,polyamine)to form polymer.The modification of Itaconic acid was mainly studied based on double carboxyl of it.Firstly,itaconyl chloride was synthesized by acylation reaction,and then semi aromatic polyamide with double bond-Poly(p-phenylene itaconamide)(PPIA)was obtained through low-temperature solution polycondensation.Finally,composite was synthesized by mixing Poly(butylene succinate)(PBS)and PPIA.During the synthesis of organic intermediates-itaconyl chloride,using itaconic acid and phosphorus pentachloride(PCl5)as the raw material,the product was synthesized by the use of solid-solid melt method.The solvent effect on the quality of the product during the purifying process was studied.And then the molar ratio,reaction time,reaction temperature,reduced pressure distillation temperature and time that had a major influence on the purity and yield of products was also investigated.The structure analysis was assessed by FT-IR,1H-NMR and the yield of products was assessed by GC.According to the FT-IR and 1H-NMR analysis of product,the target product was itaconyl chloride.In conclusion,the optimum synthesis process: using toluene as purified solvent,the dosage was 15 mL,n(PCl5): n(IA)=2.15:1,the reaction temperature was 95 °C for 5 h,and the distillation temperature was 80 °C for 2 h in purification process,the purity and yield of itaconyl chloride could reach more than 98 % and 90 %,respectively.PPIA was prepared using P-phenylenediamine and itaconyl chloride as raw materials by low temperature solution polycondensation method.The molecular structure of product was characterized by FT-IR and 1H-NMR,which confirmed the molecular structure of the target product.And then The effect of the molar ratio of raw materials,dropping time,reaction time,reaction temperature on inherent viscosity of PPIA was systematically studied:.The product was also characterized for their thermal stability and crystallization using TGA,DSC and XRD,respectively.The target polymer,which was-NH2 terminated PPIA,was identified by FT-IR and 1H-NMR.The experimental results showed that: Under the condition of the ratio of itaconyl chloride and P-phenylenediamine 1:1.05,dropping time 60 min,the reaction time 60 min,the reaction temperature-5 °C,the inherent viscosity of polymer reached maximum that was more than 1.6 dL/g.PPIA,which was prepared under low temperature,had better crystal structure according to XRD analysis.Starting gravimetric temperature of PPIA was about 270 °C in the TGA curve.The temperature of maximum weight loss rate was at 311 °C,the maximum weight loss rate was 8.67 %/min,final temperature(Tf)was 596 °C,the weight loss rate reached 86.18 %,and ΣT was 332 °C.And DSC analysis revealed that the melting temperature Tm was 202.2 °C,the melting enthalpy Hm was around 32.72 J/g,the crystallization temperature Tc was at 180.2 °C,the enthalpy of crystallization Hc was-33.64 J/g,the glass transition temperature of PPIA was about 95.5 °C.Finally,different proportions of the composites were prepared by using PPIA and PBS as raw material,and the products were investigated through crystal structure,thermal stability,non-isothermal crystallization kinetics and mechanical properties.The experimental results showed that: with the change of content of PPIA,the crystal structure of the composites did not change,but the crystallinity of the composites reduced compared with the pure PBS.Adding a small amount of PPIA had less influence on the thermal stability of the composites by TGA analysis.And compared with the pure PBS,Tm,Tg,Tc of the composites declined.And by learning from the testing of mechanical properties,the addition of PPIA had no major effect on tear properties and flexural properties,but had a great influence on the impact properties,tensile properties and hardness of PBS.The addition of PPIA greatly changed the tensile properties of the composites,which makes the tensile properties of the composites much weaker than pure PBS,and the hardness was harder than the pure PBS,the impact strength of composite materials reached the maximum when the PPIA content was 3 %. |
