A study of wood resin and cationic water soluble polymers : wood pitch fixatives

The deposition of wood resins (i.e. wood pitch, or pitch) has been a problem for the pulp and paper industry for many years. Unfortunately wood pitch fixatives do not eliminate wood resin deposition all of the time. Wood pitch deposition is a potential bottleneck in the reduction of water used to make paper. In order to address these problems a study into the nature of the interactions which occur between cationic polymeric fixatives, wood resins and wood fibres has been undertaken. During the course of these investigations a novel pitch fixative has been designed: guar gumgraft-poly(acrylamide-co-diallyldimethYlammonium chloride). The nature of interactions was explored through a number of techniques. Capillary electrophoresis (CE) was used to quantify the interaction between cationic polymeric fixatives and wood resins; for the first time. Laser particle size analysis (LPSA) was used to determine the effect of cationic polymeric fixatives addition on colloidal particle stability. Deposition studies were used to test interaction theories between cationic polymeric fixatives, wood resins and wood fibres. It was found that wood pitch fixatives worked in one of two ways; by either disrupting colloidal extractive stability, or by maintaining colloidal extractive stability. The novel fixative GG-g-p(AM-co-DADMAC) is unique in that it takes advantage of the colloidal stabilising features of a natural product (i.e. guar gum) and the wood pitch fixative properties of a synthetic polymer (i.e. p(AM-co-DADMAC)).