GMK40M Hydroxypropyl Methyl Cellulose for Construction Use Hydroxypropyl methyl cellulose (HPMC) is a non-ionic cellulose ether polymer based on cellulose, a natural polymer derived from refine cotton linter,which are offered as free flowing powder. It's ash content and Moisture content is less than 5%.And it has good water retention. AS for using,it has many applications: 1.Tile adhesive Hydroxypropyl Methyl Cellulose 2.putty powder 3.Masonry Mortars 4.Repair Mortar Hydroxypropyl Methyl Cellulose (HPMC) Hydroxypropyl Methylcellulose Ether