Study On Reinforced Polyurethane Foam

Polyurethane foam is a type of foam materials with isocyanate and polyether (or polyester) polyol as principal components, processed via special foaming technics, which possesses the excellent properties of light weight, heat insulation, sound absorption and shockproof etc. It, however, fall short of the needs for using under many special operating conditions, for instance, employing as structural materials because of its inferior mechanical strength. As a result, much attention has focused on the study of reinforced PU foam plastics all along.Many efforts have been put into the fiber reinforced PU foam, especially investigation systematically on the reinforcing mechanism and the effect on its mechanical properties at home and abroad. Presently, other fillers such as glass beads, nano-CaCOs etc. have also been introduced to PU foam systems, but there still lack of systematically research on the dispersion of fillers in PU foam matrix. This study firstly disperses reinforced materials by different means and reviews their disperse effect. On the basis of well dispersing, optimization have been made on the formula of reinforced RPUF materials as well as its processing technics. The mechanical properties of the optimized RPUF samples are then tested and the failure mechanisms of RFPU filled by different fillers are discussed. SEM is employed to observe the morphologies of the samples at each compression-deformation stage, the effect of fillers on the foam structures is reviewed and then the reinforcing mechanism is put forward. The main results are those as follows:1. For those fillers dispersed by intense shearing of planet stirrer and ultrasonic method, the results show that GF reinforcing system is fitter for intense shearing from planet stirrer to obtain better dispersion because of its relatively higher viscosity than glass beads reinforcing system, the latter is more suit for dispersing by ultrasonic method.2. In consideration of the effect of the factors involving formulae on the structure and properties of PUF plastics, investigation of formulae and processing parameters have been made, then the optimal formula and processing parameters are determined by comparing various formulae. As a result, the RPUF materials with diverse fillers such as GF, glass beads were prepared.3. The effects of the content and surface treatment of GF with length of 3mm are studied. The result shows that compression strength increased with GF content at first and decreased as GF content reached a certain scope. It also shows that the reinforcing effect of GF undergone surface treatment is higher than that of GF with no treatment. The effect mechanism of surface treatment are discussed from the microscope structure.4. The effect of different fillers on the compression behavior of PUF system has been investigated. It is found that the compression processes of RPUF reinforced by GF and glass besds are completely different. The reason of such phenomena is analyzed.