The poplar used in the experiment was taken from the Kuandian area. The water extract of the Kuandian poplar was 3.76%, 19.6% of 1% NaOH extract, 4.14% of benzene-alcohol extract, 13.57% of polypentane, and 22.99% of Klason lignin.
The experimental conclusion is:
(1) When sulphonating poplar wood, proper increase of the amount of sodium sulfite and proper extension of holding time in a certain range are favorable for sulfonation.
(2) The amount of Na2SO3 is 20% (based on Na2SO3, for absolute dry material), Na2CO3:Na2SO3=1:5 (pure mass ratio), sulfonation temperature is 145°C, holding time 40min, liquid ratio 1:4 Under the conditions of sulphonation, the condition of milled wood is determined as three-stage refining, the temperature is about 70° C., which can meet the refining requirements. The disc grinding gap is determined to be 1.5 mm, 0.1 mm, and 0.04 mm, respectively. The manufactured poplar SCMP is Whiteness and intensity meet the requirements of copying Class A newsprint.