Factors affecting the purity of hydroxypropyl methylcellulose
In the building insulation mortar, the purity of hydroxypropyl methylcellulose directly affects the quality of the construction quality, then what are the factors affecting the purity of hydroxypropyl methylcellulose? Our company takes you to answer this question.
In the hydroxypropyl methylcellulose production process, the residual oxygen in the reactor causes degradation of the hydroxypropyl methylcellulose, and the molecular weight is lowered, but the residual oxygen is limited, and it is not difficult to reconnect the broken molecules. However, the water saturation rate is also closely related to the content of hydroxypropyl groups. Some factories only want to reduce the cost and price, and do not want to increase the content of hydroxypropyl groups, so the quality can not reach the level of similar products. The water retention rate of hydroxypropyl methylcellulose is closely related to hydroxypropyl group, but it also determines its water retention rate, the effect of alkalization, the ratio of methyl chloride and propylene oxide for the whole reaction process. The concentration of alkali and the ratio of water to refined cotton determine the performance of the product.
The quality of the raw materials. The effect of alkalization. Process ratio, solvent ratio neutralization effect, some hydroxypropyl methyl cellulose is dissolved to make it turbid like milk, some are milky white, some are yellow, some are clear and transparent. To solve it, adjust from the above points. Sometimes acetic acid can seriously affect the light transmittance. The best use of acetic acid after dilution, the maximum effect is whether the mixing of the reaction is uniform, and the system ratio is stable (some materials have moisture, the content is unstable, such as the solvent used for recycling), in fact, many Factors are affecting. The equipment should be stable if the equipment is stable and the operator is skilled. The light transmittance does not exceed ±2%, and the substitution uniformity of the substituent group is controlled. Instead of uniformity, the light transmittance is definitely good.
Hydroxypropyl methylcellulose (HPMC) for construction