ASTM D543 Chemical Compatibility

Evaluating the Resistance of Plastics to Chemical Reagents ASTM D543

Scope:

ASTM D543 test to evaluate Chemical Compatibility is designed to gauge the resistance of plastic materials against chemical reagents. ASTM D543 test covers all cast, cold- and hot-molded, laminated resinous, and sheet plastic materials. The test environment is designed to simulate the application conditions of the plastic material. Chemical reagents include petroleum products and lubricants, dyes and inks, food items, cleaning agents, specialized chemicals, and other specific chemicals as per the requirement. Chemical compatibility test by ASTM D543 reports changes in appearance, dimensions, weight, and strength properties such as tensile strength and elongation upon exposing the samples for different time durations, strain conditions, and elevated temperatures.

The practices give broad principles without going into detail about all the different ways plastics are used, such as in cars where they are exposed to different fluids or in hospitals where they are exposed to cleaning and disinfecting agents. 

ASTM D543 Strain Test Procedure

Test Procedure:

ASTM D543 test covers the evaluation of plastic materials for resistance to chemical reagents. At least five specimens of a material are tested in a given set of chemical, time, and strain conditions. The specimen is first weighed and measured for its initial dimensions and then exposed to the chemical. The type of chemical exposure—wipe, spray, saturated gauze, or immersion—is designed to mimic the extent of chemical contact a sample is supposed to encounter in real-life conditions. For example, the wipe method is used when the sample is supposed to have sparse contact with the chemical like splash or spill. The immersion method is used when a sample holds the chemical as a container or a pipeline. Next, the test specimens are sealed in a container and kept at either room temperature or elevated temperature in an oven. Strain jigs designed for ASTM Type I tensile bars or ASTM Izod bars are used for the stress test of samples. This is to simulate the stress likely to be encountered by the specimen in end-use conditions. Finally, the specimens are removed from test conditions after a pre-fixed duration and evaluated for appearance, weight, and tensile properties. Compared to the initially recorded data, the change is noted and compared with data obtained from experiments set up with control samples. The values for ASTM D543 are stated in SI units.

The similarity between the testing and end-use circumstances affects how well the test findings reflect actual plastic performance or serviceability. In applications involving continuous immersion , the results of short-term tests are only relevant for removing the worst-suited materials or indicating a likely relative order of chemical reagent resistance.

Based on the specific chemicals and concentrations encountered, plastics should be evaluated for unique applications involving corrosive conditions. The method and length of reagent contact, the system’s temperature, the amount of stress being applied, and other performance aspects involved in the specific application should be taken into consideration when choosing the test conditions.

Video 01: PMA Resistance to Chemicals

Specimen size:

For ASTM D543, specimens may be taken as tensile bars, disks, or flex bars according to suitability and availability.

Results and Data:

Results of the Chemical Compatibility ASTM D543 test are reported in terms of the changes in physical appearance (clouding, swelling, cracking), decomposition, change in weight due to chemical corrosion, and change in elongation properties and tensile strength.

Conclusion:

ASTM D543 is a standard test method for evaluating the resistance of plastics to chemical reagents.