二茂铁基超支化聚(胺-酯)的热性能研究

Study on thermal property of ferrocene-containing hyperbranched poly(amine-ester)

用二茂铁甲酸对第1～4代超支化聚(胺-酯)(G1-HAPE～G4-HPAE)进行端基改性,合成第1～4代二茂铁基超支化聚(胺-酯)(G1-HPAE-Fc～G4-HPAE-Fc).通过紫外-可见分光光度计(UV-Vis)、热重(TG)、微分热重法(DTG)、差示量热扫描法(DSC)、红外光谱(FT-IR)和元素分析对HPAE-Fc的接枝率、热分解行为和热分解产物的结构进行研究.结果表明:HPAE-Fc比HPAE具有更好的热稳定性,二茂铁基团的引入能显著提高热稳定性.G3-HPAE-Fc的热分解行为分为3个热失重阶段,190℃时开始分解,温度上升到240和360℃,重量损失率分别上升到19%和58.5%,500～600℃时开始停止失重,最终重量损失率为75.8%,剩余物为碳和铁元素.热分解机理较复杂,其过程可能伴随着一些连续反应的发生,包括酯基等弱键的断裂、中间产物的形成和二茂铁基团的热分解等.

The first to the fourth generation ferrocene-containing hyperbranched poly （amine- ester） （G1-HPAE-Fc--G4-HPAE-Fc） were successfully synthesized by the esterification between ferrocenecarboxylic acid and the first to the fourth generation hyperbranched poly （amine-ester）（G1- HAPE--G4-HPAE）. Taking G3-HPAE-Fc for example, the thermal behaviors and the structure of thermal decomposition segments were investigated by UV-Vis spectrophotometer （UV-Vis）, thermal gravimetry （TG）, derivative thermal gravimetry （DTG）, differential scanning calorimetry （DSC）, FT-IR and element analysis techniques. It was shown that HPAE-Fc was more stable than pure HPAE in thermal performance and ferrocenyl group could efficiently improve the thermal stability of HPAE. The thermal decomposition of G3-HPAE-Fc was multi-stage process between 190 and 450 ℃, the weight loss of the G3-HPAE-Fe seemed to stop further at 500-600 ℃ with the final weight losing rate of 75.8%. The residual contained carbon and iron elements. A possible thermolysis mechanism was proposed as that the thermal decomposition process might contain some complicated subsequent reactions including the scission of weak links of ester bands, the formation of intermediate composites and the degradation of the ferrocene.