Quantitative determination of degree of hardening of lacquer layers pref. on optical fibres - by solvent extracting layer then chromatographically separating unreacted monomer and determining monomer content by UV spectroscopy

摘要

In the ascertaining of the deg of hardening of a monomer-contg. UV-hardened lacquer coating the remaining monomer content is determined by extracting the hardened layer using a solvent. Monomer is separated from the extract by liq chromatography then determined by UV spectroscopy. The deg of hardening of the coating is also determined. Pref., the coating may consist of several separate layers, prep. from different monomers, and the monomer components for the various layers are separated, the monomer contents ascertained and the hardening degrees of the layers determined. The solvent is pref. acetonitrile and extraction is carried out at low temp. The process can be used for calibration of the lacquers. by using extraction processes of different lengths the monomer contents of multiple layers or of differing depth of layer may be ascertained. USE/ADVANTAGE - For the protective layers on quartz glass fibres used in optical communications technology. The method is more specific than prior art processes, as only the monomer content of the extract is considered.