n-Butyl glycidyl ether
n-Butyl glycidyl ether is one of the most effective viscosity cutters for epoxy resins, and a clear example of the trade-offs that come with reactive diluents.
BGE is a butyl group attached to a single glycidyl ether (epoxide) group (molecular weight 130.18 g/mol, theoretical EEW 130). It is a thin, colorless, flammable liquid that boils at about 164 °C.
BGE is a reactive diluent: added to liquid epoxy resin, it lowers viscosity sharply so coatings, self-levelers, grouts and adhesives can be applied without solvent and can wet fillers and substrates well. Because it carries an epoxide group, it reacts into the network during cure instead of evaporating like a solvent.
As a monofunctional epoxide, BGE terminates network growth wherever it reacts.
BGE is flammable, harmful if swallowed or inhaled, irritating to skin and eyes and a skin sensitizer; some classifications also flag suspected mutagenicity. Check the SDS for the grade you use. Work with good ventilation, avoid skin contact, keep away from ignition sources and store in tightly closed containers.
A low-viscosity material that thins a resin and then reacts into the cured network, unlike a solvent that must evaporate. In epoxies, reactive diluents are glycidyl ethers.
Yes. Being monofunctional, it caps chain growth, lowering crosslink density, Tg and resistance to solvents and chemicals. Formulators balance the amount against the viscosity they need.
Yes. BGE consumes amine hydrogens, so the blend EEW changes. Calculate the combined EEW of resin plus diluent before working out the hardener ratio.
It is designed to react into the film, but part of it can evaporate before cure. How it is treated depends on the test method and the regulations that apply to your product.
