How to measure the voc standard of water-based paint by the VOC release environment chamber method?
VOC emission environment test chamber:
Water-based coatings are divided into two categories: natural water-based coatings based on natural substances or minerals (such as potassium silicate) and petrochemical water-based coatings based on synthetic resins (such as acrylic resins), These products need to do the standard measurement of VOC before leaving the factory. The equipment used is the VOC emission environment test chamber. Let's take a look at the relevant test methods.
Environmental chamber method of water-based paint to measure VOC method:
Material preparation:
Test sample: water-based paint
Test equipment: VOC release environment chamber
Equipment model: HYV-1000
Equipment manufacturer: Huanyi Instrument
other materials:
1. Carrier gas: high purity nitrogen
2. Gas: hydrogen, purity > 99.995 %
Auxiliary gas: air
Scope of application: This method is suitable for qualitative analysis of VOC components in waterborne coatings.
Method principle of the VOC release environment chamber:
After the sample is diluted with the dilution solvent, it is directly injected into a gas chromatograph equipped with two capillary columns of different polarities, and the relative retention value is calculated according to the retention time of the obtained VOC components, and the corresponding compound is found in the table. If the retention time or relative retention value of the unknown compound and the known compound are the same on two capillary columns of different polarities, it is considered to be the same compound.
Measurement steps of the VOC release environment chamber:
1.Determination of capillary column dead time (retention time of non-retained solute): According to the relevant gas spectrum conditions, after the instrument is stable, inject an appropriate amount of methane gas. Record its retention time, which is the dead time tM of a 6% nitrile propylphenyl/94% dimethylpolysiloxane column and a polyvinyl alcohol (wax) column under "gas chromatograph" conditions.
2. Dissolve an appropriate amount of paint in acetonitrile (about 10% by mass), and inject into the gas chromatograph equipped with the above two gas chromatography columns, and record the retention time tr of each component separately, calculate the relative retention value of each component according to the following formula, and find the corresponding compound in .
The above is the VOC standard method for measuring water-based coatings in the VOC release environment chamber, which is for reference only.
