The influence of polyvinylamine microgels on paper strength

Bleached softwood kraft pulp fibre suspensions were treated with six polyvinylamine (PVAm) microgels with average particle size ranging from 1.5 to 38pm, and based on two levels of crosslinking monomer. Handsheets were prepared and tested. PVAm microgels increased wet and dry paper strength compared to a linear PVAm (MW 950 kDa) when the dosage was above 0.2 wt%. The smallest microgel with the lower crosslink density gave the best performance …