Study On Anti-mold Performance Of Bamboo Plastic Composites

Bamboo resources is abundant in China.Bamboo plastic composites have many advantages,such as full utilization,perfect mechanics performance and easy to processing,which brings it a broad market in building materials,decoration and logistic fields.Bamboo plastic composites will mildew in high humidity environment,which results degradation of material performance and causes environmental pollution in daily use.Therefore,anti-mold study had become one of the key words will be studied in the process of production and application of bamboo plastic composites.In this paper,the factors causing mildew on bamboo powder was explored,and the effects of heat-treatment and anti-mold reagents was studied on anti-mold properties of bamboo plastic composites.The achievements in this research blazed new trails in improving the anti-mold properties of bamboo plastic composites.The mildew test results of main components of bamboo and their combination models showed that cellulose,hemicellulose,glucose had certain negative influences on bamboo mildew,and the influences of protein and starch were larger.The sequence was ranked according to the order of the negative influences on bamboo mildew,followed by protein,starch,cellulose,hemicellulose,and glucose,respectively.Lignin and oil had inhibitory effects against mildew,which would improve the anti-mold properties of bamboo.The effects of heat-treatment on anti-mold properties of bamboo powder and bamboo powder/polypropylene composites showed that heat-treatment could decrease the contents of cellulose,hemicellulose,glucose,starch and protein,while improved the content of lignin.Heat-treatment could contribute to the inhibition mildew of protein and cellulose,but promoted the mildew of starch and cellulose and the influences on glucose and lignin were little.Heat-treatment reduced the water absorption of bamboo powder and improved the anti-mold properties of bamboo powder,but had some influences on bamboo color at the same time.The anti-mold properties of bamboo plastic composites was improved with the heat-treatment temperature increased.The infection value was 3 dropped by 0.75,which was treat at 170?(Degrees Celsius)for 120 mins and the mold resistance efficiency was 20%.The L*value was decreased and the color change was larger with the heat-treatment temperature increased.The impacts was not obvious when the temperature was lower than 170,and it became significant when the temperature was more than 170??The L*value was also decreased and the color change was larger of bamboo plastic composites maded from heat-treatment bamboo.Heat-treatment had not significant impact on flexural properties of bamboo plastic composites when the heat-treatment temperature was below 170?.The anti-mold properties of cinnamyl alcohol and the effects of cinnamyl alcohol content on the anti-mold properties of bamboo plastic composites ware studied.The anti-mold test showed that the growth and reproduction of mouds were inhibited by cinnamyl alcohol effectly.Cinnamyl alcohol showed good stability to anti-mold when the temperature was under 200?.The anti-mold properties of bamboo plastic composites increased with cinnamyl alcohol content increased.The suitable dosage amount was about ranged from 0.5%to 1.0%against bamboo content and the infection value was ranged from 2.8 to 2.0 after 28-day mold testing,which mold resistance efficiency was ranged from 28.2%to 48.7%.Adding cinnamyl alcohol in bamboo plastic composites had no significant impacts on the color and mechanical performance.Finally,the effects of nano-Zinc Oxide modified by silane coupling agent on the anti-mold properties of bamboo plastic composites ware studied.The Fourier transform infrared(FTIR)graph and TEM images showed that silane coupling agent had a condensation reaction with nano Zinc Oxide.The length of modified Zinc Oxide was ranged from 40nm to 1000nm,and the width was almost below 100 nm.The anti-mold test results showed that modified Zinc Oxide had high effect to inhibit the growth of mold.The optimum dosage in bamboo plastic composites amount was from 1%against bamboo content,and the infection value was 1 after 28-day mold testing,which mold-resistance efficiency of bamboo plastic composites was reached 75%.The intracellular protein exudation increased with Zinc Oxide concentration improved because of modified ZnO changed the nature of cell membrane,and which could affect the metabolism of mold.At the same time,crack phenomenon on surface caused by mildew was suppressed effectively and the color change was decreased due to the high temperature in the molding process with modified Zinc Oxide adding.The influence of modified Zinc Oxide content on flexural properties of bamboo plastic composites was not significant,and addition of modified Zinc Oxide was helpful to improve the thermal stability of bamboo fiber,but had a negative effect on the thermal stability of polypropylene.