FIELD DESORPTION MASS SPECTROMETRY CHARACTERIZATION FOR RELATIVE MOLECULAR MASS AND DISTRIBUTION OF PHENOLIC RESIN

Abstract

The characterization of relative molecular mass and distribution of phenolic resins by modern analytical techniques is detailed.Common VPO,GC,HPLC and GPC methods are referenced.But these methods are restrictive in analysing the phenolic resins with more isomers.Field desorption(FD) is a term used to describe the formation of ions in the gas phase from a material deposited on a solid surface(known as an 'emitter') in the presence of a high electrical field.The field desorption mass spectrometry(FD-MS) of the phenolic resins can give the molecular ion peak and the content of the every phenol unit without fragment ion peaks.A series of phenolic resins was made with various raw materials.The phenol-formaldehyde resole resin,the phenol-formaldehyde novolac resin,the cresol-formaldehyde novolac resin and the phenol-cresol-formaldehyde novolac resin were determined by FD-MS.The sample concentration is 10 mg/mL,the heating current is 10~30 mA/min,the ionization voltage is 5~8 kV.The FD-MS shows us the molecular ion peak and the content of the every phenol unit without any fragment ion peaks.By FD-MS analysing we can also get the informations about the degree of polymerization,raw materials,characteristics and so on.So the FD-MS method is convenient and impactful for differentiating of the various phenolic resins,suitable for the characterization of relative molecular mass and distribution of the phenolic resin.