Determination of formaldehyde/urea molar ratio in amino resins by near-infrared spectroscopy

摘要: New processes for synthesis of urea-formaldehyde (UF) and melamine-fortified (mUF) resins have been developed in the last years, motivated by current concerns about effects formaldehyde on human health. All these formulations are quite susceptible to possible operation error, which can significantly influence characteristics final product. The main objective this work was implement chemometric techniques off-line monitoring product's formaldehyde/urea (F/U) molar ratio using near infrared (NIR) spectroscopy. This allows timely implementation necessary corrections case product is off-specification. Calibration models F/U were taking into account most relevant spectral regions resins, individually or combination (7502–6098 cm−1 5000–4246 cm−1) different preprocessing methods. When appropriate range methods selected, it obtain calibration with high correlation values resins. best identified three cases: UF resin (produced strongly-acid process), mUF (alkaline-acid a combined model that involves both It concluded better accuracy obtained when new each particular system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012