The difference between hydroxypropyl starch ether and cellulose ether

Now many people don’t know much about hydroxypropyl starch ether. They think that there is little difference between hydroxypropyl starch ether and ordinary starch, but it is not. The amount of hydroxypropyl starch ether used in mortar products is very small, and the addition amount of polar can achieve good quality effects.

Hydroxypropyl starch ether (HPS) is a white fine powder obtained by modifying natural plants, highly etherified, and then spray-dried, without plasticizers. It is completely different from ordinary starch or modified starch.

And hydroxypropyl methyl cellulose, also known as hypromellose, hydroxypropyl methyl red vitamin ether, is to use highly pure cotton cellulose as raw material, and treat it with lye at 35-40 ° C for half an hour, Squeeze, crush the cellulose, and age properly at 35°C, so that the average degree of polymerization of the obtained alkali fiber is within the required range. Put the alkali fiber into the etherification kettle, add propylene oxide and methyl chloride in sequence, and etherify it at 50-80°C for 5 hours, and the maximum pressure is about 1.8MPa. Then add an appropriate amount of hydrochloric acid and oxalic acid to the hot water at 90°C to wash the material to expand the volume, then dehydrate it with a centrifuge, and finally wash it repeatedly to neutrality. Widely used in construction, chemical industry, paint, medicine, military industry and other fields, respectively as film-forming agent, binder, dispersant, stabilizer, thickener, etc.

Hydroxypropyl starch ether can be used as an admixture for cement-based products, gypsum-based products and lime calcium products. It has good compatibility with other building admixtures. Used together with hydroxypropyl methylcellulose ether HPMC, it can reduce the dosage of hydroxypropyl methylcellulose (generally adding 0.05% of HPS can reduce the dosage of HPMC by about 20%-30%)), and can play a thickening effect , to promote the internal structure, with better crack resistance and improved workability.