Buffer capacity effects of delonix regia and hevea brasiliensis extractives on reactivity of selected adhesives / Alexander Vanessa

Buffer capacity of Delonix regia and Hevea brasiliensis are expected to be
different according to species where Hevea brasiliensis contains mostly latex
and Delonix regia contains mostly essential oils causing different impact and
different pH value. This phenomenon leads to differing behaviour and cure
properties for urea formaldehyde and phenol formaldehyde. To ensure good
bonding quality between resin and substrate, different glue mix formulation is
needed. Both wood species has been proven to have an effect with gelation
time that reduces the time taken for the curing of urea and phenol
formaldehyde. Curing time of urea and phenol formaldehyde was significantly
influenced by the extractive content and the pH value of both Delonix regia
and Hevea brasiliensis. The pHs value obtained for Delonix regia according
to samples mean value for chips are 4.79, flakes are 4.95 and sawdust are
4.74 respectively. Whereas pHs for Hevea brasiliensis according to samples
of chips are 5.77, flakes are 5.84 and sawdust are 5.66. This affects the
curing rate of urea formaldehyde and phenol formaldehyde by decreasing the
curing time for both selected adhesives whereby the Delonix regia shows
significant effect at less than' 0.05 significant for both urea formaldehyde
(0.047) and phenol formaldehyde (0.005) differ with Hevea brasiliensis that
shows no significant effect at more than 0.05 significant for urea
formaldehyde (0.067) and phenol formaldehyde (0.205) when using T-Test