Description Manta L321 is high purity, undiluted isobutyl trimethoxysilane. When diluted with an appropriate solvent, it can be used in the formulation of water repellent products. Upon proper application, the formulated product will penetrate and provide water repellencyby chemically reacting with the cementitious substrate. Treated substrates are hydrophobic and retain their original appearance. Manta L321 can also be used to improve the compatibility of mineral fillers or pigments in polyolefins or to ease their dispersion in nonpolar matrices. L321 is a small molecule to allow for deep penetration into the cementitious surface. This material reacts with moisture in the air and in the substrate in the presence of an alkaline or acidic environment to produce hydroxyl groups. These hydroxyl groups will bond with the substrate and itself to produce a hydrophobic treatment that inhibits water absorption into the substrate. An alkaline environment, such as new concrete, will catalyze the…