Thermal effect for aluminum powder in various pH values and linseed or machine oils absorbed by cotton or nylon fabrics

• Main Authors: Hung-kai Huang, 黃竑凱
• Other Authors: 郭勇志
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/87184557682351128861

碩士 === 國立中正大學 === 化學工程所 === 95 === When aluminum powder, AP, average particle size is 18 nanometer, damped with in aqueous solutions of various pH values, pH = 1, 3, 5, 7, 9, 11, 13, the exothermic reaction of aluminum powder in a stronger acidity and basicity aqueous solution will occur easily. The reaction of aluminum powder with pH = 13 aqueous solution is easiest and maximal Enthalpy change (DH), and minimal temperature change (∆T), occur flashy reaction, and calculated self-accelerating decomposition temperature (SADT) and no return temperature (TNR) is minimum, the exothermic reaction occur near 50℃. For experiment results, the onset temperature (Tonset) and peak temperature (Tpeak) values are pH = 13 > pH = 1 > pH = 11 > pH = 3 > pH = 9 > pH = 5 > pH = 7. The DH values are pH = 13 > pH = 7 > pH = 5 > pH = 9 > pH = 11 > pH = 3 > pH = 1. The activity energy (E) values are pH = 13 > pH = 1 >> pH = 7. The reaction order (n) and frequency factor (A) values are pH = 13 > pH = 1 >> pH = 7. The SADT and TNR calculated values are pH = 13 > pH = 1 >> pH = 7. The estimated time for aluminum damped in adiabatic and 25℃ based by the time to maximum rate (TMRad) is 25.26 days. When oils absorbed by fabrics made oilcloths, the oxidized and contact area become larger, account the oxidation easily. The Tonset,1 value are linseed oil > 10W-40 engine oil > 20W-50 engine oil. Linseed oil with cotton fabric yielded a lower onset and peak temperature, is the easiest oxidized oilcloths. The Tonset,2 value are oils + nylon > oils + cotton > pure oils, but oils absorbed by cotton or nylon, are 20W-50 engine oil > 10W-40 engine oil > linseed oil. The total enthalpy difference (∆Htotal = ∆H1 + ∆H2) are oils + nylon > oils + cotton > pure oils. SAE 10W-40 engine oil with nylon fabric has the maximal pressure and enthalpy difference, is the maximal thermal effect of reaction oilcloths.