Preparation And Characterization Of Tung Oil-Rosin-Based Polyester Internal Sizing Agent

A series of tung oil-rosin-based polyester (TRP) used as internal sizing agents were prepared using rosin, tung oil, maleic anhydride, and glycerol. TRP structure and properties were examined using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The TRP latexes were subsequently used as internal sizing agents, and the sizing properties were evaluated using a scanning electron microscope (SEM), a video-based dynamic contact angle measuring device and a Cobb absorbency tester. The optimal conditions for preparing the TRP sizing agent were as follows: the hydroxy-carboxyl ratio of the material was 0.25; the maleic anhydride dosage was 20 % of rosin; and the tung oil dosage was 40 % of rosin. Under the best conditions, the sized paper Cobb-60 was 15.6 g/m(2), the tensile index was 45.1 N.m/g, the burst index was 3.1 kPa.m(2)/g, and the tear index was 15.6 mN.m(2)/g.