BAMO-GAP三嵌段共聚物的热分解动力学及反应机理

Kinetics and Mechanism of Thermal Decomposition Reaction of BAMO/GAP Tri-Block Copolymer

用热重-红外-质谱(TG-IR-MS)联用技术对三嵌段共聚物的热分解产物进行了表征,利用Ozawa公式和Kissinger公式研究了聚3,3-双叠氮甲基氧杂丁环/叠氮缩水甘油醚(PBAMO/GAP)三嵌段共聚物的热分解动力学,得到其分解活化能为148.40 kJ/mol,指前因子lnA=33.5s-1,通过Grane公式计算得反应级数n=1。最后,对不同产物的红外和质谱特征峰进行了归属,实验结果证明,PBAMO/GAP三嵌段共聚物的分解产物主要有CH4/CH3+、N2O、NO2、N3/HN3、HCN+、CHO+和NH2+,其主要分解机理与一般烷基化合物相同,主要过程为CH2-N3分解为氮宾,氮宾经重排生成亚胺,随后有NH3生成。但其分解过程中存在经过-CH2N3进一步分解得到N3和HN3的特殊过程。

Thermogravimetry-infrared spectrum-mass spectrometry（TG- 1R-MS） simuhaneous techniques was used to study the thermal decomposition mechanism of poly3, 3-bis （azidomethyl）oxetane/glycidyl azide polymer （PBAMO/GAP） tri-block copolymer. The activation energy Ea and the pre-exponential factor A calculated by Kissinger and Ozawa method are 148.40 kJ/mol and InA = 33.5 s-1 , respectively. The order of the decomposition reaction obtained by Crane＇s method is n = 1. The IR/MS characteristic peaks of gas products of the decomposition were assigned. Results show that the gas products consist of CHa/CH3＋ , N2O, NO2, N3/HN3, HCN＋ , CHO＋ and NH2＋ The mechanism of thermal decomposition of the copolymer is consistent with that of common azide compounds. These typical courses could be expressed as follow： nitrene was released after the decon：position of CH2 - N3, and then rearrangement occurred, imine Was released, and then NH3. But during the decomposition of PBAMO/GAP tri-block copolymer, another routine was observed, which is the release of CH2 - N3, and then the release of N3 and HN3. Keywords： poly3, 3-bis （azidomethyl） oxetane; glycidyl azide polymer; thermal decomposition; TG-IR-MS simultaneous techniques