Liquid nucleating additives for improving thermal insulating properties and mechanical strength of polyisocyanurate foams
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The effects of liquid-type nucleating silane additives on the cell structure, mechanical strength, and thermal insulating properties of the polyisocyanurate (PIR) foams have been studied. The PIR foams synthesized with hexamethyldisilazane (HMDS) as a silane additive showed the smaller average cell size and lower thermal conductivity than those of the PIR foams prepared with the hexamethyldisiloxane, dimethoxydimethylsilane, and hexadecyltrimethoxysilane. When HMDS was added, average cell size of the PIR foam was becoming smaller due to lower surface tension of the polyol solution, thereby the nucleation rate and number of bubbles produced were increased and then the cell size becomes smaller. The additives likely act as nucleating agents during the formation of PIR foams. The smaller cell size appears to be one of the major reasons for the improvement of thermal insulation properties and mechanical properties of the PIR foams. From the results of cell size, thermal conductivity, and mechanical strength of the PIR foams, it is suggested that the HMDS may be the efficient liquid-type additive for the reduction of cell size and improvement of the thermal insulation property of the PIR foams.
KeywordsFoam Polyol HMDS Nucleate Agent Lower Surface Tension
This research was supported by a grant (code BB3-101) from Carbon Dioxide Reduction & Sequestration Research Center, one of the 21st Century Frontier Programs funded by the Ministry of Education, Science and Technology of Korean government.
- 5.Kim SH, Kim BK, Lim H (2008) Macromol Res 16:467Google Scholar
- 6.Oertel G (1993) Polyurethane handbook. Hanser Publishers, New YorkGoogle Scholar
- 10.Gibson LJ, Ashby MF (1997) Cellular solids. Cambridge University Press, CambridgeGoogle Scholar
- 13.Grimminger J, Muha K (1995) J Cell Plast 31:48Google Scholar
- 14.Han MS, Choi SJ, Kim JM, Kim YH, Kim WN, Lee HS, Sung JY (2009) Macromol Res 17:44Google Scholar
- 15.Kang JW, Kim JM, Kim YH, Kim WN, Jang W, Shin DS (2009) Macromol Res 17:856Google Scholar
- 17.Lewis RJ, Chichester S (2007) Hawley’s condensed chemical dictionary, 15th edn. Wiley, New YorkGoogle Scholar
- 23.Griffin JD, Skochdopole RE (1964) In: Baer E (ed) Engineering design for plastics. Van Nostrand Reinhold, LondonGoogle Scholar
- 24.Esmaeilnezhad E, Rezaei M, Razavi MK (2009) Iran Polym J 18:569Google Scholar