Adsorption behaviour of cationic fixatives and their effect on pitch deposition

The behaviour of the four different polymeric fixatives in the presence of wood extractive components with and without fibres was investigated. Cationic polyacrylamide (CPAM) and high and medium charge co-polymers of polyacrylamide and poly(diallyl-dimethyl ammonium chloride (polyDADMAC) were found to stabilise the wood extractive colloids in solution, as well as to attach the wood resins to the fibre. Polyethylenimine (PEI) was shown to cause non-selective deposition onto both fibre and non-fibre surfaces, as well as reduce the amount of wood extractives in the dissolved and colloidal phase. PEI was also found to preferentially interact with triolein and the medium charge co-polymer exhibited preference in fibre-attachment of oleic acid.