方案摘要
方案下载| 应用领域 | 石油/化工 |
| 检测样本 | 天然橡胶 |
| 检测项目 | |
| 参考标准 | TG-DTG |
Two common problems in the TG-DTG analysis of unknown elastomer vulcanizates and probable solutions are discussed. The first problem concerns the difficulty in quantitatively determining the oil and elastomer in the compound in cases where their volatilization temperature range overlaps. After a review of the published works which studied this problem, isothermal TG (with or without vacuum) along with the use of "High Resolution" TG equipment is recommended. The second problem concerns separate determination of carbon residue from the elastomers and added carbon black in the compound, which very often oxidizes together. Subtraction of the carbon residue formed by the elastomers, determined by previous analyses, from the total weight loss in oxygen, was suggested in the literature. However, the quantity of char depends on type of the elastomer, as well as its concentration, curative type and amount and rate of heating. The problem is not, therefore, fully resolved. Experiments under slow feed of lean oxygen gas and isothermal temperature were also suggested in the literature. Under this condition, oxidation of carbon black and char may occur at slightly different temperatures and overlapping is minimized. However, this could be achieved only for large and medium particle size blacks (soft blacks) which oxidize at higher temperatures and not for the smaller particle size blacks, (used mostly in tire treads). Further work under slow feed of lean oxygen with a superimposed isothermal program and/or vacuum is recommended. The capability of the recently announced "High Resolution Thermogravimetric Analyzer" should also be explored.?
Two common problems in the TG-DTG analysis of unknown elastomer vulcanizates and probable solutions are discussed. The first problem concerns the difficulty in quantitatively determining the oil and elastomer in the compound in cases where their volatilization temperature range overlaps. After a review of the published works which studied this problem, isothermal TG (with or without vacuum) along with the use of "High Resolution" TG equipment is recommended.
The second problem concerns separate determination of carbon residue from the elastomers and added carbon black in the compound, which very often oxidizes together. Subtraction of the carbon residue formed by the elastomers, determined by previous analyses, from the total weight loss in oxygen, was suggested in the literature. However, the quantity of char depends on type of the elastomer, as well as its concentration, curative type and amount and rate of heating. The problem is not, therefore, fully resolved. Experiments under slow feed of lean oxygen gas and isothermal temperature were also suggested in the literature. Under this condition, oxidation of carbon black and char may occur at slightly different temperatures and overlapping is minimized. However, this could be achieved only for large and medium particle size blacks (soft blacks) which oxidize at higher temperatures and not for the smaller particle size blacks, (used mostly in tire treads). Further work under slow feed of lean oxygen with a superimposed isothermal program and/or vacuum is recommended. The capability of the recently announced "High Resolution Thermogravimetric Analyzer" should also be explored.
利用微量热技术研究病毒结构与宿主细胞受体结合反应
等温量热法研究水泥水化
等温微量热法研究生物制品长时间稳定性评价
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