Oxidative stability of lubricants measured by PDSC CEC L-85-T-99 test procedure

Summary The CEC L-85-T-99 pressure differential calorimetry (PDSC) test was developed in Europe for ACEA E5 specification for heavy duty diesel oils. This test differentiate between base oils, additives, indicates synergies between antioxidants and correlates with other oxidation tests. Occasionally, the PDSC test can have difficulties to provide a true value for the OIT, which can vary between samplings. This work gives evidence of such case and concludes that variability in results is caused by variability in the oil rather than in the test itself. It appeared possible that certain oils might not be fully homogenous and this could produce a problem for representative PDSC sampling.     

Thermal investigation of oil and biodiesel from <Emphasis Type="Italic">Jatropha curcas</Emphasis> L.

Biodiesel is susceptible to autoxidation if exposed to air, light and temperature, during its storage. Physic nut (Jatropha curcas L.) seeds show potential application for biodiesel production since its oil yields high quality biodiesel. This work aims to evaluate the thermal behavior of the physic nut oil and biodiesel, from several Brazilian crops, by means of thermoanalytical techniques. Thermogravimetry (TG) and pressurized-differential scanning calorimetry (PDSC) were used in order to determine the applicability of physic nut biodiesel as fuel. Results suggest that physic nut biodiesel is a practical alternative as renewable and biodegradable fuel able to be used in diesel motors.     

抗氧剂对植物油氧化稳定性影响的高压差示扫描量热法评价

利用高压差示扫描量热法（ＰＤＳＣ）研究了二烷基二硫代氨基甲酸锌（ＶＡＺ）、２,２′－亚甲基双（４－甲基－６特丁基苯酚）（２２４６）、苯江三唑（ＢＴＺ）和二烷基对苯二胺（ＤＢＡ）４种抗氧添加剂对菜子油氧化稳定性的影响,得到了它们抗氧化作用的大小顺序。别外,根据队仑尼乌斯公式计算了不同油样氧化反应的活化能,证明了ＰＤＳＣ是一种快速简便评价基础油氧化稳定性的方法,适用于抗氧添加剂配方的设计工作。     

高压差示扫描量热法评价抗氧剂对润滑油基础油氧化稳定性的影响

结合环境友好润滑油产品的开发工作,利用高压差示扫描量热法(PDSC)研究了3种典型抗氧剂T501(2,6-二叔丁基对甲基苯酚)、T531(N-苯基-α-萘胺)和DNA(二壬基二苯胺)对菜籽油氧化稳定性的影响,并考察了浓度对抗氧剂作用效果的影响。结果证明,PDSC是一种快速简便评价基础油氧化稳定性的方法,适用于抗氧剂的筛选工作。另外,根据阿仑尼乌斯公式计算了不同油样氧化反应的表观活化能。     

Matching Cure Characteristics of Automotive Rubber Compound and Polyurethane Coating

The present investigation focuses on matching cure characteristics of EPDM rubber compound and polyurethane (PU) coating using temperature modulated and pressure differential scanning calorimetry (TMDSC, PDSC). TMDSC provides a detailed and better understanding of the curing process of model rubber system as well as complex automotive rubber compounds. The low level of unsaturation present in EPDM, results in the small heat of vulcanization (2–5 J g^–1), which is difficult to accurately measure using conventional differential scanning calorimetry (DSC). Thus, curing of highly filled EPDM compound was investigated using TMDSC. The kinetics of PU curing was monitored using pressure DSC (PDSC), and heat of curing was determined as 4.2 J g^–1 at 10°C min^–1 heating rate. It is found that complex automotive compounds and the PU coating are curing simultaneously. This revised version was published online in July 2006 with corrections to the Cover Date.