ADHESIVES FROM AUTOHYDROLYSIS BAGASSE LIGNIN, A RENEWABLE RESOURCE - PROPERTIES OF BAGASSE BOARD MADE WITH A PITCH-LIGNIN ADHESIVE MIXTURE AND ITS THERMAL-BEHAVIOR AS ANALYZED BY DSC

The combination of inexpensive materials such as pitch with lignin sho wed promise making binder systems in the manufacture of bagasse boards . The pitch had a plasticizing effect on the lignin and could be direc tly mixed with hexamethylene-tetramine without an additional formaldeh yde condensation stage before heat curing. Differential scanning calor imetry (DSC) was useful for describing the cure behaviour of pitch wit h lignin. This technique clearly showed that pitch with a lignin const ituent had a lower heat of reaction during the cure than pitch by itse lf. It proved that lignin acted as a low reactive filler. The exotherm ic reactivity of the pitch-lignin system decreased by a fraction equal to the lignin content of the resin, which indicated that only the pit ch part was responsible for the exothermic reaction of the resin durin g curing. The pitch and pitch-lignin resins also showed a low exotherm ic curing peak temperature. These properties of pitch were regarded as beneficial for the moulding with lignin.