Buy HPMC - High-Quality Hydroxypropyl Methylcellulose for Your Needs
Furthermore, MHEC can also help to reduce the risk of segregation and bleeding in cement. Segregation occurs when the components of a mixture separate, with heavier particles sinking to the bottom and lighter particles rising to the top. Bleeding, on the other hand, refers to the migration of water to the surface of the mixture. Both segregation and bleeding can negatively impact the quality and performance of cement. However, by incorporating MHEC into the mixture, these issues can be minimized. MHEC acts as a stabilizer, preventing the separation of particles and the migration of water, resulting in a more homogeneous and stable cement mixture.
Thermal stability of HPMC and MHEC is affected by their gel temperature. In general, the gel temperature of HPMC is around 60℃-75℃ depending on its group content and different production technique. Due to the characteristics of MHEC group, it has a higher gel temperature, usually > 80℃. Therefore its stability under high temperature is better that HPMC. On the other hand, because there are more hydrophilic groups in the structure of MHEC, it has better hydrophilicity. The water retention rate of MHEC in mortar is a little higher than HPMC at the same dosage of products with the same viscosity.