In the building insulation mortar and putty powder, the size of hydroxypropyl methylcellulose purity directly affects the quality of engineering construction, so what are the factors that affect the purity of hydroxypropyl methylcellulose? To help you answer this question today.
In the production process of hydroxypropyl methylcellulose, the oxygen remaining in the reaction kettle will lead to the degradation of hydroxypropyl methylcellulose and reduce the molecular weight. However, the residual oxygen is limited, so it is not difficult to reattach the broken molecules. The main saturation rate and hydroxypropyl content has a great relationship, some factories just want to reduce the cost and price, do not want to improve the content of hydroxypropyl, so the quality can not reach the level of similar foreign products.
The water retention rate of hydroxypropyl methylcellulose and hydroxypropyl also has a great relationship, and for the whole reaction process, hydroxypropyl methylcellulose also determines the water retention rate of hydroxypropyl methylcellulose. The effect of alkalization, the ratio of chloromethane to propylene oxide, the concentration of alkali and the ratio of water to refined cotton all determine the performance of the product.
The quality of raw materials, alkalization effect, process ratio control, solvent ratio and neutralization effect, all determine the quality of hydroxypropyl methyl cellulose, some hydroxypropyl methyl cellulose made to dissolve after like milk is very cloudy, some milky white, some yellow, some clear and transparent. If you want to solve it, adjust from the above points. Sometimes acetic acid can seriously affect the transmittance, acetic acid is best used after dilution, the biggest impact or reaction stirring is uniform, the system ratio is stable (some material moisture, content is not stable, such as the recovery of the solvent), in fact, many factors are affected. With the stability of the equipment and the operation of trained operators, the products produced should be very stable. The transmittance should not exceed ±2%, and the substitution uniformity of the substituent group should be controlled well. Uniform substitution, transmittance must be good.
Therefore, good product quality is determined by raw materials, production technology, and other factors. Only strict control from one end to the end can produce products with stable quality.