Subtitution of Pentane by a Mineral Clay as a Blowing Agent for Phenolic Foam

摘要

The main drawback of using pentane as a blowing agent for rigid phenolic foam is its flammability.It presents a real risk of explosion and therefore requires specific conditions for handling and storage.In this article its replacement by a mineral clay composed mainly of calcium carbonate as the major component in addition to some other metal oxides,was investigated in terms of performance requirements.The proposed formulations contained instead of pentane different proportions of the clay and a mixture of toluene sulphonic acid and sulfuric acid.It was found that,except for a slight increase in the thermal conductivity,all other properties such as foam density,water absorption,permeability to water vapor,compression resistance,and flexural resistance were within the plant specifications.To complete the study,it is recommended to investigate possible adverse long-term effects in terms of chemical resistance and foam morphology.