Anti-fungal performance and mechanical–morphological properties of PVC and wood/PVC composites under UV-weathering aging and soil-burial exposure

• IPBC had the ability to retard deterioration of PVC under UV and soil exposure.
• UV and soil exposure had a more pronounced effect on properties of WPVC composites.
• UV aging had more effect on chemical changes of PVC, compared to soil aging effect.
• Soil exposure had more susceptibility to reduced anti-fungal efficacy than UV aging.

The anti-fungal performance and mechanical–morphological properties of polyvinylchloride (PVC) and wood/polyvinylchloride composites (WPVC) doped with fungicide were studied for the effects of UV-weathering aging (0–32 days) and soil-burial exposure (0–6 months). Hevea brasiliensis Muell (HB) wood was used for producing the WPVC-HB composites and 3-iodopropinyl-N-butylcarbamate (IPBC) was used as a fungicide. Anti-fungal potential was evaluated using the disk diffusion method. It was found that the effects of UV-weathering aging and soil-burial exposure resulted in decreases in the flexural properties and dimensional stability of WPVC-HB composites, but the properties of pure PVC were not affected. Deterioration in the mechanical properties of WPVC-HB by both of the aging effects was slightly diminished by IPBC addition, but the thermal property tended to decrease due to IPBC degradation. FTIR and TGA results showed that UV-weathering had a greater effect on chemical changes of PVC in WPVC composites. Samples UV-aged for 32 days had decreased anti-fungal performance from 81.4 to 28.3%, while the 6-month soil-burial samples decreased from 81.4 to 4.4%. SEM studies showed evidence that addition of IPBC slowed the deterioration of the material properties for both the UV-weathered samples and the soil-burial samples.