AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfo...AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.展开更多
Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-co...Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-complexation from P1 or P2, whereas, concentration-dependent pseudorotaxane structures were generated by P3 which bearing more flexible side chain. Interestingly, the obtained pseudo[1]rotaxanes exhibited a dynamic fast assembly process upon adding NaBF4, resulting in the formation of Na＋-induced pseudorotaxanes.展开更多
The melts of a series of low molecular weight poly（ethylene oxide）（PEO） fractions on mica surfaces were studied by atomic force microscopy（AFM） and X-ray reflectivity（XRR） measurement.The PEO ultrathin films w...The melts of a series of low molecular weight poly（ethylene oxide）（PEO） fractions on mica surfaces were studied by atomic force microscopy（AFM） and X-ray reflectivity（XRR） measurement.The PEO ultrathin films were obtained via static dilute solution casting.Different from the melts of the PEO with both methoxyl（（—OCH3）） end groups that are dewetted on the mica surface,a pseudo-dewetting phenomenon of the PEO melts was observed when either one end group of the PEOs becomes hydroxyl（—OH） or both are hydroxyl groups.The wetting layer thicknesses of the pseudo-dewetted melts were measured to be 4.5～4.7 nm,independent on the molecular weight and the end groups of PEOs.However,the PEO melt droplets on the wetting layer varied from spherical caps with relatively high contact angle to irregular shapes with relatively low contact angle when increasing the molecular weight and the hydrophobicity of end groups of PEOs.展开更多
从4,4＇-二氟三苯二酮（DFTBDK）和酚酞出发,利用＂拟高稀（pseudo high dillution）＂技术,一步法制备酚酞聚芳醚酮酮环状齐聚物（c-PEKK-C）,成环率78%。基质辅助激光解吸电离飞行时间质谱MALDI-TOF MS数据表明,聚合产物系聚合度为n=...从4,4＇-二氟三苯二酮（DFTBDK）和酚酞出发,利用＂拟高稀（pseudo high dillution）＂技术,一步法制备酚酞聚芳醚酮酮环状齐聚物（c-PEKK-C）,成环率78%。基质辅助激光解吸电离飞行时间质谱MALDI-TOF MS数据表明,聚合产物系聚合度为n=2~8的环状低聚物,其中以二、三聚体为主要成分（占环化产物的85%）。运用J-S高分子环化理论证实4,4＇-二氟三苯二酮的单体结构有利于形成环状化合物。以4,4＇-联苯二酚钾盐为催化剂,在300~350℃范围内,N2气保护下,环状齐聚物进行熔融开环聚合反应得到相应的线性高相对分子质量酚酞聚芳醚酮酮（ROP-PEKK-C）,GPC测得其Mw为1.2×10^5。展开更多
基金the National Science and Technology Support Project of "the Eleventh Five-year Plan"(2006BAE03B06-03)the New Century Talents Support Program of Chinese Education Department (NCET-04-0614)
文摘AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.
基金the financial support from the National Natural Science Foundation of China(Nos.21472089,21572101)the National Natural Science Foundation of Jiangsu(No.BK20140595)
文摘Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-complexation from P1 or P2, whereas, concentration-dependent pseudorotaxane structures were generated by P3 which bearing more flexible side chain. Interestingly, the obtained pseudo[1]rotaxanes exhibited a dynamic fast assembly process upon adding NaBF4, resulting in the formation of Na＋-induced pseudorotaxanes.
文摘The melts of a series of low molecular weight poly（ethylene oxide）（PEO） fractions on mica surfaces were studied by atomic force microscopy（AFM） and X-ray reflectivity（XRR） measurement.The PEO ultrathin films were obtained via static dilute solution casting.Different from the melts of the PEO with both methoxyl（（—OCH3）） end groups that are dewetted on the mica surface,a pseudo-dewetting phenomenon of the PEO melts was observed when either one end group of the PEOs becomes hydroxyl（—OH） or both are hydroxyl groups.The wetting layer thicknesses of the pseudo-dewetted melts were measured to be 4.5～4.7 nm,independent on the molecular weight and the end groups of PEOs.However,the PEO melt droplets on the wetting layer varied from spherical caps with relatively high contact angle to irregular shapes with relatively low contact angle when increasing the molecular weight and the hydrophobicity of end groups of PEOs.
文摘从4,4＇-二氟三苯二酮（DFTBDK）和酚酞出发,利用＂拟高稀（pseudo high dillution）＂技术,一步法制备酚酞聚芳醚酮酮环状齐聚物（c-PEKK-C）,成环率78%。基质辅助激光解吸电离飞行时间质谱MALDI-TOF MS数据表明,聚合产物系聚合度为n=2~8的环状低聚物,其中以二、三聚体为主要成分（占环化产物的85%）。运用J-S高分子环化理论证实4,4＇-二氟三苯二酮的单体结构有利于形成环状化合物。以4,4＇-联苯二酚钾盐为催化剂,在300~350℃范围内,N2气保护下,环状齐聚物进行熔融开环聚合反应得到相应的线性高相对分子质量酚酞聚芳醚酮酮（ROP-PEKK-C）,GPC测得其Mw为1.2×10^5。
