Test Method for Boiling Point of Ethylene Glycol-Based Engine Coolant
Ethylene glycol-based engine coolant, also known as antifreeze, is mainly composed of water, ethylene glycol, freezing point depressants, corrosion inhibitors, defoamers and other additives. It features high boiling point, low foaming tendency, excellent viscosity-temperature performance, strong corrosion resistance and good scale inhibition. Under normal conditions, it is a clear and transparent liquid that exhibits different colors depending on the additives used. Its freezing and boiling points are not fixed due to variations in formulation. Currently, the mainstream antifreeze products on the market have a freezing point range of -60℃ to -25℃ and a boiling point range of 100℃ to 120℃.
Purpose of the Experiment：
In the fields of chemistry and scientific research, determining the boiling point of ethylene glycol-based engine coolant enables the evaluation of the coolant's performance status and the judgment of whether its performance has degraded due to long-term use. It ensures high-temperature protection, preventing premature boiling when the engine is under high load, which would otherwise lead to pressure imbalance in the cooling system and reduced heat dissipation efficiency. It guarantees low-temperature adaptability, ensuring stable operation under different climatic conditions and avoiding damage caused by freezing or boiling. It monitors the introduction of impurities during the production process to ensure product quality.
The experiment is carried out in accordance with the SH/T 0089 standard. The SH0089 Engine Coolant Boiling Point Tester manufactured by Shengtai Instruments complies with this standard and is selected for the experiment.
Experimental Instruments
①SH0089 Engine Coolant Boiling Point Tester
② Auxiliary components including condenser tubes, round-bottom flasks, thermometers, graduated cylinders, cleaning reagents, etc.
Testing method
①Prepare the sample. This instrument is applicable to diluted or concentrated engine coolant. If the sample fails to meet the requirements, perform dilution or concentration in accordance with SH/T 0065.
②Turn on the instrument, calibrate the thermometer, and insert it into the side port of the flask.
③Measure 60ml of the diluted sample or unused concentrated sample, pour it into the flask, and add three to four boiling chips.
④Insert the dry and clean condenser tube into the flask and secure it. Attach latex tubes to the water inlet and outlet to fill the condenser jacket with water.
⑤Press the heating switch to bring the sample to a boil within 10 minutes. After boiling, reduce the heating intensity to maintain the specified reflux rate of the sample and read the temperature.
⑥Record the temperature and the atmospheric pressure during the experiment, then conduct temperature correction and calculation.
Experimental Results：
Test analysis shows that the boiling point of this engine coolant is 108°C, which complies with the standard.