Anti-algal Performance and Strength of Wood Poly(vinyl chloride) Composites with Different Wood Types

摘要

Anti-algal performance and mechanical properties of wood/poly(vinyl chloride) composites (WPVC) filled with commercial algaecides were studied. Three types of wood flour used; namely: Xylia Kerrii Craib & Hutch (XK), Hevea Brasiliensis Muell (HB) and Mangifera Indica Linn (MI), were considered based on their constituents and physical characteristics of wood particles. Commercial algaecides, namely Isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) and Terbutryn (N2-tert-butyl-N4-ethyl-6-methylthio-1,3,5-triazine-2,4-diamine) with concentration range from 0 to 1,500 ppm were doped in PVC and WPVC composites. Clear zone test using Chlorella vulgaris as testing algae was used for evaluating the anti-algal performance and the adhesion of algal cell on the surface of PVC and WPVC specimens were observed via optical (OM) and scanning electron microscope (SEM). Flexural strength, flexural modulus and surface roughness of specimens were also examined. The results revealed that the Terbutryn samples clearly performed a great anti-algal performance while the Isoproturon samples did not. Regarding the effect of wood types, the WPVC with XK wood had the most satisfactory anti-algal performance. The recommended dosage of Terbutryn for WPVC with XK was 500-1,000 ppm. The increases in algaecide content in PVC and WPVC composites were not found to correlate with the changes in flexural properties and surface roughness of materials. The SEM results indicated that the specimens treated with the algaecides did not show the adhesion of algal cell and bio-film formation.