Studies On The Preparation And Reinforcing Of Rigid Polyurethane Foam (RPUF)

One step method was applied to prepare rigid polyurethane foam (RPUF) with high performances. It was discussed that the effects of foaming agent (H2O), cross linking agent (TMP), chain extender (BDO), foam stabilizer (B8433, B8450, B8534, AK8805, AK8818) and isocyanate index on the mechanical properties (such as tensile strength, compressive strength, flexural strength and impact strength), heat conductivity, density, pore structure, foaming ratio, degree of cross linking, thermal stability and storage modulus of RPUF. Results showed that RPUF with good pore structure, strength and toughness was prepared at components that polyatomic alcohol 100 phr, isocyanate index 1.05, H2O 0.5 phr, foaming agent 1.5 phr, trimethylolpropane (TMP) 1.0 phr, and 1,4- butylene glycol 1.0 phr, and the effect of foaming agent on properties of RPUF was modest.It was examined that effects of polyatomic alcohols (PS-400A, TMN-700 and SU-310) on properties of RPUF. The RPUF with best performances, impact strength 5.14kJ/m2 and elongation at break 25% was prepared by PS-3152.It was investigated that the effect of proportions of the mixture of TMN-700 and TDB-2000 on properties of RPUF. Results indicated that RPUF with best toughness and strength, impact strength 5.22kJ/m2 and good dimensional stability was fabricated at TMN-700/TDB-2000 of 90/10.Using PVA as activating agent, the influences of nano acrylic ester rubber powder and XNBR powders with and without activating on the properties of RPUF were studied. We found that nanoscale dispersion of rubber powders in RPUF were achieved in the aid of activating agent, and dispersion condition was best at acrylic ester rubber powder 3.0 phr and XNBR powder 4.0 phr. Tensile strength, compress strength, impact strength and elongation at break of RPUF, prepared with acrylic ester rubber powder by activating, are improved by 10%,13%,42% and 73% than that of RPUF prepared by acrylic ester rubber powder without activating. Similar results were obtained for RPUF fabricated by XNBR powders that after activating, tensile strength, compress strength, impact strength and elongation at break of RPUF are improved by 18%,19%,60% and 62%.