Scope:

ASTM D7029-09 covers standard procedures to evaluate the gelation and exotherm curves of polyesters and vinyl ester resins. The “Standard 180 °F (82 .2 °C) Exotherm Curve” is obtained using this test method. On mixing with initiators, polyester and vinyl ester resins undergo polymerization. ASTM D7029-09 helps determine the reactivity of the polyester and vinyl ester resins during polymerization. This standardized method is used for the research and development of resins by manufacturing companies. Polymer companies using such resins as raw materials for production analyze them by ASTM D7029-09 for quality control purposes.

Test Procedure:

The polyester or vinyl ester resin to be analyzed is taken in a beaker and mixed with an initiator. Upon mixing, polymerization of the resin occurs. The polymerization reaction is accelerated by heat released. A thermocouple is used to measure the exotherm generated by the resin. The curve is plotted and the temperature against time data is recorded during the test. The peak exotherm temperature is determined by the test method.

Specimen size:

100 ± 0.02g of resin
100 ± 0.02g of initiator
1 g of styrene monomer

Data:

The following values are supposed to be measured using the recording pyrometer during the test:

Gel Time—150 °F (65.5 °C) to 190 °F (87.8 °C).
Cure Time—150 °F (65.5 °C) to the maximum temperature).
Interval Time—190 °F (87.8 °C) to the maximum temperature.
Peak Exotherm Temperature.