摘要
探讨了酰基化合物存在下催化剂和CO2用量对2-吡咯烷酮聚合制备生物基聚氨基丁酸(PGABA)的影响。利用核磁共振氢谱(1H-NMR)、傅里叶转变红外光谱(FT-IR)、X射线衍射(XRD)、差示扫描量热仪(DSC)、热重分析仪(TG)表征了产物的化学结构、晶型以及热性能。结果表明:催化剂用量固定时,产率随CO2用量增加而降低;催化剂用量不大时,分子量随CO2的增加先提高后减小;催化剂用量较大时,CO2用量对分子量的影响不显著。不同CO2用量下增加催化剂用量,产物分子量出现极大值,而产率的变化较复杂。增加CO2用量对PGABA的晶型、熔点无影响,PGABA的热分解温度提高,热稳定性增加。
The influence of catalyst and CO2 on the synthesis of bio-based poly(γ-aminobutyric acid)(PGABA)was investigated in the presence of an acyl compound initiator.The molecular structure and crystal form of the products were examined using magnetic resonance spectroscopy(1H-NMR),Fourier-transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD).Thermogravimetry(TG)and differential scanning calorimetry(DSC)were used to evaluate the thermal properties of PGABA prepared via different ways.Results indicated that the addition of CO2 had an adverse effect on the yield of PGABA.When the mole fraction of acyl catalyst was fixed at 6%or 7%,the molecular weight increased at first and then decreased with increasing the dosage of CO2,while the yield decreased successively.When the mole fraction of catalyst was increased to 9%,increasing the dosage of CO2 less affected the molecular weight of PGABA,but the yield kept decreasing.On the other hand,the absence of the initiator dramatically decreased the yield of PGABA in the CO2 containing system.At the different dosages of CO2,the molecular weight rose firstly and then went down with increasing catalyst mole fraction.Such a trend became not evidence at a high dosage of CO2.The impact of catalyst mole fraction on the yield was a little complex.The yield could reach a maximum with increasing the catalyst mole fraction when CO2 mole fraction was less than 13.2%,above which a positive effect of the catalyst on the yield was presented.The crystals of PGABA samples prepared through various methods were all of theαform and independent of the mole fraction of catalyst,initiator,and CO2.Moreover,introducing CO2 less affected the melting point of PGABA,but led to the increase of the thermal decomposition temperature and the improvement of the thermal stability of PGABA.
作者
陈晨
陈涛
赵黎明
邱永隽
CHEN Chen;CHEN Tao;ZHAO Liming;QIU Yongjun(Shanghai Key Laboratory of Advanced Polymeric Materials,School of Materials Science and Engineering;Key Laboratory of Bio-Based Material Engineering of China National Light Industry Council;State Key Laboratory of Bioreactor Engineering,R&D Center of Separation&Extraction Technology in Fermentation Industry,School of Bioengineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《功能高分子学报》
CAS
CSCD
北大核心
2020年第3期290-296,共7页
Journal of Functional Polymers
基金
国家重点研发计划项目(2017YFB0309302)
上海市自然科学基金(17ZR1407200)。
