Cresol#x2013;lignin liquors produced as waste from bagasse pulping, at different temperatures (160#xB0;#x2013;190#xB0;C) for 1.5 h and at 170#xB0;C for different times (0.75#x2013;3 h) were tested to evaluate their reactivity in both alkaline and acidic media toward preparation of cresol#x2013;lignin formaldehyde resins. The effects of different polymerization parameters#x2014;e.g., time, temperature, ratio of polyphenols to formaldehyde, and reaction medium (acidic or alkaline)#x2014;on the yield and properties of produced resins were detected. The yields of the resins produced in alkaline medium are higher than those produced in acidic medium.
展开▼
