This study aims to develop highly hygroscopic bio-based co-polyamides(CPs)by melt co-polycondensation of polyamide(PA)56 salt and PA66 salt with varying molar fractions.The functional groups and the chemical structure...This study aims to develop highly hygroscopic bio-based co-polyamides(CPs)by melt co-polycondensation of polyamide(PA)56 salt and PA66 salt with varying molar fractions.The functional groups and the chemical structure of the prepared samples were determined by Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(^(1)H-NMR)spectroscopy.The relative viscosity was determined with an Ubbelohde viscometer.The melting behavior and the thermal stability of CPs were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Furthermore,the water absorption behavior of CP hot-pressed film was studied.The results reveal that the melting point,the crystallization temperature and the crystallinity of CPs firstly decrease and then increase with the molar fraction of PA66 in CPs.The copolymerization of PA56 with PA66 leads to an obvious increase in water absorption.The CPs with PA66 molar fraction of 50%possess a high saturated water absorption rate of 17.6%,compared to 11.6%for pure PA56 and 7.8%for pure PA66.展开更多
Enabling thermoplastic polyamides with significant room temperature phosphorescent(RTP)performance holds great application potential,but remains challenging.Herein,we develop an efficient crystallization-mediated appr...Enabling thermoplastic polyamides with significant room temperature phosphorescent(RTP)performance holds great application potential,but remains challenging.Herein,we develop an efficient crystallization-mediated approach to fabricate RTP-active bio-based polyamide 56(PA56)that simultaneously achieves an exceptional phosphorescence lifetime of 1.214 s and maintains robust mechanical properties with a tensile yield strength exceeding 80 MPa.Comprehensive characterization demonstrates that the material's RTP characteristics can be precisely tuned through controlled crystallization,where the synergistic effects of electron-rich carbonyl group aggregation(functioning as phosphorescent centers)and interchain hydrogen-bonding networks effectively suppress non-radiative decay pathways.This crystallization-dependent modulation enables systematic optimization of PA56's phosphorescent properties.Furthermore,we successfully demonstrate practical applications leveraging these unique RTP features,including advanced information encryption/anti-counterfeiting systems and innovative visualization techniques for real-time moisture monitoring and mechanical load assessment in PA56 products.This work establishes a general design strategy for engineering thermoplastic polyamides with tailorable phosphorescence,opening new avenues for smart material development.展开更多
基金National Key Research and Development Program of China(No.2017YFB0309400).
文摘This study aims to develop highly hygroscopic bio-based co-polyamides(CPs)by melt co-polycondensation of polyamide(PA)56 salt and PA66 salt with varying molar fractions.The functional groups and the chemical structure of the prepared samples were determined by Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(^(1)H-NMR)spectroscopy.The relative viscosity was determined with an Ubbelohde viscometer.The melting behavior and the thermal stability of CPs were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Furthermore,the water absorption behavior of CP hot-pressed film was studied.The results reveal that the melting point,the crystallization temperature and the crystallinity of CPs firstly decrease and then increase with the molar fraction of PA66 in CPs.The copolymerization of PA56 with PA66 leads to an obvious increase in water absorption.The CPs with PA66 molar fraction of 50%possess a high saturated water absorption rate of 17.6%,compared to 11.6%for pure PA56 and 7.8%for pure PA66.
基金supported by the Young Elite Scientists Sponsorship Program by Beijing Association for Science and Technology(BAST)(BYESS2023086)the Fundamental Research Funds for the Central Universities(buctrc202225)the Scientific Research Projects of China National Petroleum Corporation(PRIKY23093)。
文摘Enabling thermoplastic polyamides with significant room temperature phosphorescent(RTP)performance holds great application potential,but remains challenging.Herein,we develop an efficient crystallization-mediated approach to fabricate RTP-active bio-based polyamide 56(PA56)that simultaneously achieves an exceptional phosphorescence lifetime of 1.214 s and maintains robust mechanical properties with a tensile yield strength exceeding 80 MPa.Comprehensive characterization demonstrates that the material's RTP characteristics can be precisely tuned through controlled crystallization,where the synergistic effects of electron-rich carbonyl group aggregation(functioning as phosphorescent centers)and interchain hydrogen-bonding networks effectively suppress non-radiative decay pathways.This crystallization-dependent modulation enables systematic optimization of PA56's phosphorescent properties.Furthermore,we successfully demonstrate practical applications leveraging these unique RTP features,including advanced information encryption/anti-counterfeiting systems and innovative visualization techniques for real-time moisture monitoring and mechanical load assessment in PA56 products.This work establishes a general design strategy for engineering thermoplastic polyamides with tailorable phosphorescence,opening new avenues for smart material development.
