HPMC Cellulose Hydroxypropyl Methyl Properties and Applications in Various Industries
The chemical structure of MHEC mirrors that of HPMC. It encompasses hydroxyethyl groups linked to the hydroxyl groups within cellulose. The degree of substitution (DS) governs the quantity of hydroxyethyl groups incorporated, influencing MHEC's solubility, viscosity, and other intrinsic traits. MHEC remains stable under standard conditions and exhibits resistance to microbial degradation.
In another study, Jenni et al. stained MHEC with a fluorescent dye and visualized and quantified the migration of MHEC through the capillaries of mortars. They found that MHEC accumulates at system interfaces exhibiting a reduced porosity. From this, they conclude that the cellulose ethers can migrate through the pore system and are therefore not or only partly adsorbed on cement particles under wet conditions [18]. In a later publication from this group they state that the dissolved CE is transported downwards through the capillary pores, but accumulates at the contact layer and substrate surface, which act as micro-filters [19].