Hydrolytic stabilization of chemically modified Bambusa vulgaris Shrad ex JC Wendl
N A Sadiku, S M Akintayo
The main drawback which greatly limit the utilisation of bamboos is their high moisture intake, biodegradation and physical properties changes with environmental variations. To prevent excessive dimensional changes and improve moisture properties of bamboo, Bambusa vulgaris was chemically treated with acetic-anhydride without co-solvent. To evaluate the influence of acetylation on the moisture properties. The weight gain (WPG), Bulking coefficient (BC), Rate of reaction (RR), Volumetric Swelling (VS) and Anti-swelling Efficiency as well as changes in VS and ASE upon long term water soaking and weight loss to leaching (WL) were determined. The results indicated no significant effect of reaction temperature and time on the WPG, BC, VS and ASE of the acetylated bamboo while reaction time had significant influence on RR and WL. None of the bamboo samples had more than 3.67% WPG and 54.69 % ASE. The maximum values of ASE of acetylated bamboo was 54.69% at 2.785 WPG while the lowest 13.08% was recorded at 2.89% WPG. However, at the lowest WPG of 1.61 %, ASE of 35.88% was recorded while the highest WPG of 3.67% gave ASE of 32.84 %. ASE varied from 13.08 % to 54.69% the lowest being recorded at 140oC, 30 mins reaction time while the highest (54.69%) was recorded at 100oC, 90 minutes reaction time. Temperature had no influence on the initial and final volumetric swelling and final anti-swelling efficiency of the modified bamboo samples but reaction time had significant effect on initial ASE. Volumetric swelling of modified samples increased from 8.47 to 18.58% while the unmodified samples swelled from 9.42% to 43.22% within 7 days water soaking period. Acetic anhydride form chemical bonds that are stable to solvent extraction in B. vulgaris. Acetylating at 120°C for 30 and 60 minutes is suitable for B. vulgaris to positively influence its sorption properties.
Keywords: WPG, cell bulking, anti-swelling efficiency, dimensional changes, B. vulgaris
Conference: 18-04-29/05-03 Johannesburg, South Africa