GB/T 36965-2018 in English

3.1 Precautions for sample preparation

Micro electronic balance requirements: Graduation value 0.01mg, range greater than 1g. Samples must be weighed accurately to 0.01mg, and the mass difference between the uncrosslinked sample and the crosslinked sample must be within ±5%.

3.2 Key points for instrument calibration

Differential scanning calorimeter (DSC) requires regular calibration of the baseline, temperature and energy measurement devices. It is recommended to use standard substances such as indium or tin for calibration. Ensure that in actual testing, the baseline drift does not exceed 0.1mW, and the baseline curvature must also be less than 0.1mW.

3.3 Data analysis and processing

The formula for calculating the degree of crosslinking according to the DSC curve is: $$ G = \frac{H_1 - H_2}{H_1} \times 100\% $$, where G is the degree of crosslinking, in %. The difference between the calorific value H₁ of the uncrosslinked sample and the residual calorific value H₂ of the crosslinked sample determines the degree of crosslinking.