Solid content determination method

This standard is applicable for determining the solid content of resins, curing agents, filler pigments, and paints

This standard refers to GB/T1725-979 Determination of Solid Content in Coatings

Unsaturated polyester resins - Determination of solid content

Experimental terminology: Solid content, the mass percentage of non-volatile matter contained in the measured sample under specific conditions

Experimental principle: Heat a sample of known mass, evaporate any volatile substances under these conditions, and then measure the amount of residue

Experimental instruments: precision electronic scale (sensitivity 0.001g), electric constant temperature drying oven, drying oven (using color changing silicone gel as a desiccant), tin foil box (60mm x 60mm)

Experimental steps:

1. Mark the tin paper boxes one by one and divide them into five groups. Dry in an oven at an appropriate temperature (see Appendix 1 for specific temperature) for 10 minutes to remove any water or sweat vapor that may have been present during the tin foil preparation process. After removal, place it in a sealed drying oven and cool it to room temperature. Then use an electronic scale to measure the individual weight and record the data. --—M1

2. Pour the uniform sample into a clean and dry weighing bottle.

3. Pour the sample into the tin box and weigh 2 ± 0.002g of the sample. Liquid samples can be dropped using a dropper to ensure accurate quality up to 0.001g, carefully covering the entire bottom of the box with the sample. Weigh 5 groups according to the law and record the data. --—M2

4. Place the tin box horizontally in the top of the preheated oven with a constant temperature of 120 ± 2 ℃.

5. After 60 ± 2 minutes, take out the tin box and place it in a dryer for 20 minutes to room temperature, weigh it, then bake it in an oven for 30 minutes, take it out and cool it to room temperature in a dryer, weigh it until the weight difference between the two weighings is no more than 0.01g. --—M3

6. When the viscosity of the sample is high, use a pipette to suck 1-2g of strong solvents (such as ethyl ester, butyl ester, or acetone, etc.) and place them in a tin box. Stir with a paper clip for about 30 minutes before placing them in the oven for baking. However, be careful to stir with the round end of the paper clip to avoid piercing the tin box

Experimental results:

1. Calculate the solid content according to the following formula SC - Determine the solid content of the sample

M1- Tin Box Single Weight

M2- Sample quality

M3- Tin Box and Residual Quality

SC＝(M3-M1)÷M2X100%

After calculating the SC values of the five sets of data, remove the maximum and minimum values, and then take the average

2. Two parallel experiments were conducted. The relative error between the two experimental results should not exceed 3%, and if it exceeds 3%, the experiment should be repeated. Take the average as the measurement result.