Antifungal properties and material characteristics of PVC and wood/PVC composites doped with carbamate-based fungicides

Abstract

Antifungal properties of polyvinylchloride (PVC) and wood/PVC composites (WPVC) were studied with two different fungicides through disk diffusion and dry weight techniques against Aspergillus niger as a testing fungus. Three different types of woods, including Xylia kerrii Craib & Hutch.(XK), Hevea brasiliensis Muell.(HB), and Mangifera indica Linn.(MI), were used. The disk diffusion results revealed that the addition of 3‐iodopropinyl‐N‐butylcarbamate (IPBC) in the PVC and WPVC markedly reduced the diameter of fungi, whereas the addition of methylbenzimidazole‐2‐ylcarbamate(Carbendazim) did not. The results from IPBC samples by the dry weight technique corresponded to those by the disk diffusion method. Adding fungicides tended to slightly increase the flexural properties of PVC, whereas in the case of WPVC those properties were deteriorated by IPBC and carbendazim additions. The total color change was less when IPBC only was introduced into PVC. FTIR spectra suggested that no chemical structure changes were observed after the addition of IPBC and carbendazim. The higher surface contact angle and fungicide release values for IPBC samples could imply greater diffusibility of IPBC in PVC and WPVC matrices, accompanied by increased antifungal activity. WPVC with HB wood showed the best antifungal performance, at an optimal concentration of 10,000 ppm, when compared with XK and MI woods. POLYM. ENG. SCI., 54:1248–1259, 2014. © 2013 Society of Plastics Engineers

Effects of UV-accelerated weathering and natural weathering conditions on anti-fungal efficacy of wood/PVC composites doped with propylene glycol-based HPQM

“…An explanation for this phenomenon is that introducing the wood flour, which is highly hydrophilic in nature [25,26] into the WPVC makes the PVC become more hydrophilic. As a consequence, more water molecules can be absorbed into/onto the HPQM/WPVC surfaces [19]. Another possible reason was that the methoxy groups (-OCH 3 ) in the aminosilane could be hydrolyzed to produce silanol [-OSi(OH) 3 ] and these silanol groups would develop covalent siloxane bonds by reaction with OH groups of wood during the wood flour pretreatment process, and then the PVC could bond with the amine group of aminosilane modified wood flour by an acid-base interaction [27][28][29].…”

“…Fungal growth inhibition [19] against A. niger, a testing fungus, was used for anti-fungal evaluation of specimens. The procedure was commenced by preparing an initial fungal spore suspension containing 10 4 spores/mL in 100 mL of 1:1 potato dextrose broth (PDB)/potato dextrose agar (PDA).…”

“…Coulthwaite et al [18] reported 2-n-octyl-4-isothiazolin-3-one (OIT) encapsulated on silica or zeolite and showed the best long term anti-fungal performance of pPVC materials. Kositchaiyong et al [19] reported that addition of anti-fungal agent (Carbendazim or IPBC) in WPVC composites tended to increase the anti-fungal (Aspergillus niger) efficacy. 2-Hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate (HPQM), or BioCleanAct™ (product code BCA-101A0; Micro Science Tech Co., Ltd., Hwaseong, South Korea), is a new commercial anti-microbial agent that is claimed to be an environmental friendly organic biocide with low toxicity, light elution, and excellent color stability under UV light and pyrolysis conditions.…”

Effects of biocide treatments on durability of wood and bamboo/high density polyethylene composites against algal and fungal decay

“…This illustrated that the wood in WPC materials was in fact susceptible to biodeterioration . Thereafter, many researches were carried out to test the biological durability of WPCs, and subsequent studies clearly showed that WPC materials were susceptible to biodegradation …”

“…Numerous studies have shown that various decay fungi significantly affect the wood in WPCs. The result is a substantial loss of weight and strength of WPCs after exposure to decay fungi . Attack by mold fungi does not always deteriorate the mechanical and physical properties of the composites.…”