X.M.Min
,
Y. Daiand C.W.Nan National Key Laboratory of Advanced Technology for Materials Synthesis and Processing
,
Wuhan University ofTechnology
,
Wuhan 430070
,
China
金属学报(英文版)
Al NMRand quantum chemistry calculation have been used to study thestructureof γ Al2O3 and AlON. The NMRspectra arecharacterized bythree distinctresonance peaksat114 , 66 and 12 , corresponding to 〔AlN4〕,〔AlO4〕and 〔AlO6〕respectively. The uantum chemistrycalculationsshowqd thatthe models with vacancieslocated at octahedralsitein B block are morestablethanthose with vacancieslocated attetrahedralsitein A blockforboth of γ Al2 O3 and AlON. In AlON, nitrogen atoms preferentially replace oxygen atoms in〔AlO4〕tetrahedrons, and the model with 〔AlN4〕is morestablethan that with 〔AlO4 xNx〕(x= 1 ,2 and 3) and 〔AlO6 - yNy〕(y= 1 ,2 ,3 and 4) , which isin agreement with theexperimental analysisby NMR.
关键词:
Al2 O3 and AlON
,
null
,
null
,
null
宋守许
,
田光涛
,
查辉
,
余德桥
高分子材料科学与工程
利用超高压水射流装置将废旧子午线轮胎胎面胶破碎为橡胶粉末并进行橡胶回收,运用低场核磁共振、红外光谱、扫描电镜、粒度分析等手段对橡胶粉末的物理和化学结构进行表征.结果表明,橡胶材料在破碎过程中发生了常温脱硫反应,脱硫效果随着水射流压力的提高呈先升高后降低的趋势,并在200 MPa压力处达到最佳,材料内部交联信号强度下降到54.85％.根据红外光谱推测了可能发生的化学反应,研究了引发脱硫反应的力学因素,认为水射流引起的剪切应力场作用是脱硫反应发生的主要原因.
关键词:
超高压水射流
,
胎面胶
,
橡胶回收
,
核磁共振
,
脱硫机理
