Aminosilicone (3-[(2-Aminoethyl)amino]propyl methyl, dimethyl, methoxy-terminated)

CAS 102782-92-3 is a functionalized polydimethylsiloxane (PDMS) — an aminosilicone bearing pendant aminoethylaminopropyl side chains and methoxy end groups. It is the primary fabric-protection active in Chemical Guys HydroThread and similar non-fluorinated fabric protectant formulations. The aminoethylaminopropyl side chains bind to hydroxyl groups on fabric fibers (cotton, polyester, nylon), anchoring the hydrophobic silicone backbone to the textile surface. The methoxy end groups hydrolyze in the presence of moisture to form silanol bonds, enhancing adhesion durability. The result is a silicone film that causes liquids to bead on the fabric surface without penetrating fiber bundles. This is organosilicon chemistry — no fluoropolymer, no PFAS. The ECHA database lists H319 (eye irritation Cat 2A) as the relevant health classification at formulation strength. No respiratory or skin H-codes are issued. Siloxane polymers are generally persistent in the environment but do not bioaccumulate in organisms at typical consumer-product use concentrations.