Abstract
Hydrochlorofluorocarbon (HCFC) is an ozone-depleting substance that is subject to environmental regulations based on the Montreal Protocol, and in South Korea, which is regarded as a developing country, its use will be restricted in phase starting in 2013 until finally being prohibited in 2030. HCFC is regulated Based on the Tokyo Protocol, HCFC is a regulated construction material for carbon dioxide reduction with GWP of 1,700~2,400 times that of $CO_2$, with a GWP of 1. At present in South Korea, the foaming agent used for extruded polystyrene insulation consists of solely HCFC, whereas it has been replaced with eco-friendly foaming agents (carbon dioxide, hydrocarbons) by advanced countries such as European countries and Japan as a measure for environmental change. A review of the physical properties of insulation material utilizing $CO_2$ showed that the compressive strength, flexural failure load, thermal conductivity, combustibility and moisture permeance satisfied the standards of KS M 3808 foaming polystyrene by 4~60%, and it was determined that the foaming agent could be replaced with $CO_2$ by 30%. Also, it is thought that adding graphite will improve the thermal conductivity of the insulation material.