Abstract
Polyamideimde resins (AI) were prepared from 4, 4′-diphenylmethane diisocyanate (MDI) or 4, 4′- diaminodiphenylmethane (DAM) and trimellitic anhydride (TMA) or trimellitic acid chloride (TMC) by the aid of solution polymerization, precipitation polymerization or non-aqueous dispersion polymerization (NAD, Table 1, Table 2). Melt flow rates of their powdery AI were investigated and discussed relating to the chemical structures.
The most convenient polymerization procedure for getting the high melt flow rates AI were solution polymerization of MDI/TMA and DAM/TMC, solution poymerization of MDI/TMA and NAD of MDI/ TMA could not give AI with high molecular weight (Fig. 1).
It is considered that the flow rate depends on molecular weight distribution and microheterogenity (Table 3). The most convenient method to produce powdery AI was precipitation polymerization and NAD, especially, NAD was excellent to produce spherical AI in the range of particle size from 1 to 100 μm (Fig. 6). By applying NAD, spherical AI including cross-linked AI, having functional group such as -COOH, -NCO and -SO3Na, were prepared, and their properties were investigated (Table 4).
