应用功率补偿型微量热仪测定磷酸脲的比热容
Accurate heat capacity determination of urea phosphate using a power compensation microcalorimeter
龙秉文 1王宇航 1胡明明 2李通 1池汝安 3李韡4
作者信息
- 1. 绿色化工过程省部共建教育部重点实验室/化工与制药学院,武汉工程大学,湖北 武汉 430205
- 2. 中国五环工程有限公司,湖北 武汉 430223
- 3. 湖北三峡实验室,湖北 宜昌 443007
- 4. 天津大学 化工学院,天津 300072
- 折叠
摘要
采用功率补偿型微量热仪连续测量样品在精准控制的升降温过程中的微小能量变化,从而得到准确的比热容数据.对水、蓝宝石、苯甲酸等6种物质(4种固体、2种液体)比热容的测定结果与文献值的偏差在1.2%以内,表明该方法具有较高的测量精度,适用于各种固体和液体比热容的连续测量.以磷酸和尿素为原料,通过络合反应、冷却结晶制备得到了磷酸脲晶体产品.元素组成分析、XRD、红外光谱和熔点测试结果表明,所制备的磷酸脲具有很高的纯度和结晶度.进一步,采用该方法测量了磷酸脲在-20～100℃范围内的比热容,并对测试数据进行了关联和相关热力学函数计算.本工作为磷酸脲在食品加工领域的应用提供了重要数据,也为各类食品添加剂比热容提供了一种新的高效测定方法.
Abstract
To accurately determine the specific heat capacity,a power-compensated microcalorimeter was utilized to continually measure the modest energy changes that occurred throughout the perfectly regulated temperature rise and decrease process.The specific heat capacities of six substances(four solids and two liquids),including water,sapphire,and benzoic acid,determined by this method were found to be within 1.2% deviation of the literature values,indicating that the method has high measurement accuracy and is suitable for continuous measurement of various solids and liquids.Urea phosphate with high purity and crystallinity was obtained by complexation reaction and cooling crystallization using phosphoric acid and urea as raw materials,and was characterized by elemental composition analysis,XRD,infrared spectroscopy,and melting point test.Furthermore,the specific heat capacities of urea phosphate were determined in the temperature range of-20 to 100℃by this method.The obtained data were well correlated by a second-order polynomial and related thermodynamic functions were computed.This study provides crucial data for the application of urea phosphate in the field of food processing,as well as a new and efficient method for determining the specific heat capacity of various food additives.
关键词
磷酸脲/比热容/微量热/直接法Key words
urea phosphate/specific heat capacity/microcalorimetry/direct method引用本文复制引用
出版年
2024
NETL
NSTL
万方数据