Effect of Zeolite on the Hygroscopicity and Fire Retardant Properties of Poplar Wood Treated with APP

This paper, retardant concentration and zeolite type (4A type and 13X type) were selected as variable to study the effects of different treatment on drug loading, moisture absorption rate and oxygen index. Results showed that the drug loading, moisture absorption rate and oxygen index increased with the increase concentration of APP. Zeolite could reduce the moisture absorption rate of the treated samples, together increase the drug loading. After treated by compound solution of 20% APP and 2% zeolite (4A type), the drug loading of poplar veneer reached maximum, with the value of 5111 kg/m3. Two zeolite types made moisture absorption rate reduced by 14%-18%. The oxygen index reached 487% when it was treated with 15% of APP solution, and the oxygen index decreased to 415% and 467% when 2% of 4A or 13X zeolite were added into the 15% of APP solution, which reached B1 grade of flame retardant material standard.