MOLECULAR MECHANICS EXPERIMENTAL METHODS APPLIED TO VARNISH PRIMER/WOOD INTERACTIONS/

Molecular mechanics modelling is used to calculate the energies of int eraction, hence the molecular level energy of adhesion at the interfac e with crystalline cellulose I of three different photopolymerisable p rimers and of a polyester varnish at the interface with the primer/cel lulose assembly. The energy of interaction for just one of the primers with the statistically most common conformation of amorphous cellulos e has also been obtained for comparison. Experimental results of adhes ion by a standard peel test and by thermomechanical analysis, in which the effect of energy dissipation by crack tip propagation has been re spectively minimised or is not present, hence in which the energy of i nterfacial interaction is nothing else than the work of adhesion, corr elated well with the energies of interaction calculated by molecular m echanics. An equation correlating energy of interaction at each finish /cellulose interface with the deflection and flexibility derived by th ermomechanical analysis, and with the number of bond rotational degree s of freedom as well as degree of networking of the finish has been de rived and is presented. Discussion of the relationship of the effects found with the glass transition temperature of the finish is also pres ented.