Estimation of the long-term dimensional stability performance of hydrocarbon blown rigid polyurethane foams for insulation-a novel approach

摘要

For years,HCs with zero ODP and low GWP have been used as alternative B.A.(blowing agents) in the appliance industries.The "improvement of insulation performance" and "lowering costs" are significant factors in the development of R-PU (rigid polyurethane) foams especially blown with HCs.The development of R-PU foam with a considerable low density for cost effectiveness is progressing at present.Positive experiences as to the long-term dimensional stability of pentane blown R-PU foam accelerated this movement.The most important factor in the development of R-PU foam with a considerable low density is long-term dimensional stability.In this report we proposed a novel long-term dimensional stability test and its appropriateness was discussed.The influence of formulation and the boiling point (B.P.) of B.A.on long-term dimensional stability have also been studied.The use of a blowing agents mixture of cyclopentane and iso-or n-pentane with a lower B.P.allowed the achievement of density savings.The understanding of the relation between the formulation and long-term dimensional stability is an important issue for the development of R-PU foam.