Plastic Mortars, Sealants, and Caulking Compounds - ACS Publications

8 Sealing and Caulking Compositions RAYMOND B. SEYMOUR

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 13, 2016 | http://pubs.acs.org Publication Date: November 27, 1979 | doi: 10.1021/bk-1979-0113.ch008

University of Southern Mississippi, Hattiesburg,MS39401

Since the use of sealants and caulking compositions i s essential for energy conservation i n the construction of modern buildings, large quantities of hot melt and room temperature curing sealants and caulking compounds were used worldwide i n 1978. This segment of the organic coatings polymer industry i s diffuse and complex and usually considered as part of the one m i l l i o n tons adhesives i n d u s t r y . The U.S. Putty, Caulk and Sealant Industry consumes $15 m i l l i o n worth or a c r y l i c and polyvinyl acetate latex annually. Sealants may be puttylike mastics, noncured tapes or cured gaskets. The widely used puttylike sealants which are emphasized i n this and subsequent chapters are available as both one component and two component formulations. The term sealants i s used to describe compositions used as load bearing joints and the term "caulks" is used to describe those used as nonload bearing compositions. The o r i g i n a l caulking compositions were bituminous or vegetable oil-based products but these have been supplemented by polybutene and butylrubber, natural and synthetic rubber, polyvinyl acetate, a c r y l i c r e s i n , polyurethanes, polysulfides and s i l i c o n e s . The l a s t two are discused i n d e t a i l in Chapters 11 and 12. The life expectancy of polyurethane sealants has been considered to be 10 years while that of butyl rubber, a c r y l i c s , polysulfides and silicones has been stated to be 15 years. Additional information on application techniques and tests for sealants i s readily available. Of course, bituminous caulking materials under the name of slime were mentioned i n Genesis and Exodus and evidentally these 1

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0-8412-0523-X/79/47-113-101$05.00/0 © 1979 American Chemical Society

In Plastic Mortars, Sealants, and Caulking Compounds; Seymour, Raymond B.; ACS Symposium Series; American Chemical Society: Washington, DC, 1979.


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compositions performed §atisfactorly as s e a l a n t s f o r Noah's ark. Caulking m a t e r i a l s used d u r i n g the 15th and more recent c e n t u r i e s were based on asbestos and l i m e s t o n e / f i l l e d d r y i n g o i l s . These p u t t i e s which were used as g l a z i n g s e a l a n t s have been upgraded to meet Class I I I requirements of F e d e r a l S p e c i f i c a t i o n TT-1-791 by the i n c o r p o r a t i o n of a polybutene. In a d d i t i o n to t h e i r use on highways and r o o f s , both hot poured and room temperature hardening bituminous compositions have been used as c a u l k i n g m a t e r i a l s and s e a l a n t s i n b u i l d i n g c o n s t r u c t i o n . The c l a s s i c a l agphalt/asbestos s e a l a n t s contained v o l a t i l e s o l v e n t s and t h e i r r e s i s t a n c e to s o l v e n t s was i n c r e a s e d by the i n c o r p o r a t i o n of c o a l t a r . These s e a l a n t s have a l s o been modified by the a d d i t i o n of elastomers, such as powdered rubber, and f i l l e r s , such as sawdust.12 Polybutenes have been used f o r almost a century and w h i l e they are s t i l l used, most of t h i s type s e a l a n t contains b u t y l rubber, which i s a copolymer of butene and isoprene. Most b u i l d i n g s p e c i f i c a t i o n s , including Federal S p e c i f i c a t i o n , TT-S-001637, r e q u i r e s o l u t i o n s of b u t y l rubber i n s t e a d of o i l based c a u l k i n g compositions. S e l f c u r i n g b u t y l rubber s e a l a n t s may c o n t a i n p h e n o l i c resins,1§- r e s o r c i n o l and hexamethylenetetramine.-lâ L i q u i d n a t u r a l rubber, SBR, a c r y l o n i t r i l e elastomers, neoprene, and c h l o r o s u l f o n a t e d polyethylene are a l s o used as sealant compositions. F i l l e d depolymerized n a t u r a l rubber and SBR l a t e x are r e a d i l y cured at room temperature by the i n c o r p o r a t i o n of u l t r a a c c e l e r a t o r s . ^ 3 F i l l e d l i q u i d neoprene s e a l a n t s are cured at room temperature by the a d d i t i o n of l e a d oxide, t e r t i a r y amines or epoxy r e s i n s . Neoprene s e a l a n t s covered by a top coat of white c h l o r o s u l f o n a t e d polyethlyene are being used on s o l a r c o l l e c t o r s . 2 1 Mixtures of c a r b o x y l terminated a c r y l o n i t r i l e elastomers (CTBN) and l i q u i d epoxy r e s i n s cure r e a d i l y at room temperature i n the presence of b i s phenol A and a m i n e s . — Coal tar-epoxy r e s i n , two component epoxy r e s i n , and epoxypolyester r e s i n systems have been used as sealants.2i C h l o r o s u l f o n a t e d polyethylene (Hypalon) has been used as a r o o f i n g composition and blends of t h i s polymer and neoprene have been used as s e a l a n t s . Block copolymers of styrene and butadiene (Kraton) have a l s o been used as sealants.24 Emulsions of p o l y v i n y l acetate and p o l y a l k y l a c r y l a t e s have been used as tub c a u l k i n g compositions, s p a c k l i n g compounds and as b u i l d i n g sealants.2J> A c r y l i c s e a l a n t s which harden i n the presence of powdered i r o n or copper meet Federal S p e c i f i c a t i o n s TT-S-00230C.26-2? L i q u i d monomers, such as polyethylene g l y c o l dimethacrylate and b u t y l alpha—cyanoaerylate have been used as room temperature c u r i n g s e a l a n t s . 2§-\29 Two component a c r y l i c systems which are known as second generation a c r y l i c s i n the U.S. and as "honeymoon adhesives" i n Europe are discussed i n Chapter 10. A c r y l i c r e s i n s have been



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used w i t h silicones.2S. Of course, as discussed i n Chapter 11, the l a t t e r as w e l l as f l u o r o s i l i c o n e s are w i d e l y used as sealants.22 Room temperature cured (RTV) s i l i c o n e s are used as p o t t i n g compounds and as i n s i t u formed gaskets. These compositions are toughened by the a d d i t i o n of styrene o r b u t y l a c r y l a t e which form minute strands o f f i b e r i n s i t u when they polymerize.22. S i l i c o n e s e a l a n t s and coatings are being used i n the NASA space shuttles.22 P a i n t a b l e , f a s t curing-octoate-cured s i l i c o n e s e a l a n t s are a l s o a v a i l a b l e . 2 4 Simple t e s t s f o r u t i l i t y , based on a f i l l e d g l a s s tube, have been described. Since t h e i r i n t r o d u c t i o n l e s s than a century ago, the use of polyurethane s e a l a n t s has grown tremendously. The use o f polyurethane sealant s3£~"-27 and ways o f m i n i m i z i n g t o x i c i t y hazards c h a r a c t e r i s t i c o f these m a t e r i a l s have been o u t l i n e d . 3 £ Polyethlyene s u l f i d e (Thiokol) was discovered s e r e n d i p i t i o u l y by Dr. P a t r i c k who was attempting t o s y n t h e s i z e an a n t i f r e e z e . This elastomer which was introduced commercially i n 1929, had l i m i t e d use u n t i l l i q u i d polymers w i t h r e a c t i v e t h i o l end groups were obtained by the r e d u c t i o n o f t h i s elastomer. The l i q u i d polyethylene s u l f i d e s are r e a d i l y o x i d i z e d and cured by the a d d i t i o n o f o x i d a n t s , such as l e a d peroxide.22 These s e a l a n t s , which a r e , by f a r , the most important a p p l i c a t i o n o f p o l y s u l f i d e s are described i n d e t a i l i n Chapter 12. These s e a l a n t s which are a v a i l a b l e as both one and two component compositions4P~4-i are a l s o used as s e a l a n t s f o r ammonium n i t r a t e i n rocket f u e l . The annual s a l e s f o r the l a t t e r are about $150 m i l l i o n . 4 2 Regardless o f t h e i r composition, these s e a l a n t s are used to prevent the p e n e t r a t i o n o f waterborne s a l t s i n t o cracks i n concrete s u r f a c e s , t o prevent leakage o f f u e l tanks, and t o s e a l c r e v i c e s i n r e s i d e n t i a l and commercial b u i l d i n g s . These s e a l i n g and c a u l k i n g compositions not only conserve energy i n these a p p l i c a t i o n s but they save energy by f u n c t i o n i n g as thermal i n s u l a t o r s . Because o f the emphasis on energy c o n s e r v a t i o n , t h e use o f these m a t e r i a l s w i l l i n c r e a s e but s i n c e they perform a v i t a l s e a l i n g f u n c t i o n i n s o l a r energy equipment, t h e i r use w i l l i n c r e a s e a t a much greater than a n t i c i p a t e d rate.43. Literature Cited 1. 2. 3. 4. 5. 6. 7.

Kirshenbaum, G.S. Polymer News (1974) 1/2 2, (1978) 4 285. Schulenberg, F. Am Paint Coat J. (1977) 62(14) 82. Schulenberg, F . Am Paint Coat J. (1978) 63(24) 48. Gruman, E.B. Bau Magazin (1977) (2) 94. Maslow, P. "Chemical Materials of Construction" Structure Publishing Co., Farmington, MI, 1974. Prane, J.W. "Sealants and Caulks" Handbook of Adhesives 2nd Ed. I. Skeist, ed., Van Nostrand-Reinhold, New York, 1976. F l i c k , E.W. "Adhesives and Sealant Compounds and Their Formulations" Noyes Data Corp., Park Ridge, NJ, 1978.


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Damusic, A. "Sealants" Reinhold, New York, 1967. Cook, J.P. Construction "Sealants and Adhesives" Wiley Interscience, New York, 1960. 10. Panek, J. "Building Seals and Sealants" ASTM Spec Tech B u l l 606, Philadelphia, PA 1976. 11. Rairdon, C.T. "Adhesives and Sealants i n Buildings 'Service Systems'" i n "Adhesives and Sealants i n Buildings," P78. Publication 577, Building Research Institutes, Washington, D.C., 1958. 12. McNamara, C.R. "Sealing Compounds and Gaskets" in "Adhesives and Sealants i n Buildings," P51. Publication 577, Building Research Institute, Washington, D . C . , 1958. 13. Jackson, B.S. "Industrial Adhesives and Sealants" Hutchison, London, 1976. 14. Aberth, W.C. "Caulking Compounds" i n "Adhesives and Sealants i n P46. Publication 577, Building Research Institute, Washington, D.C. 1958. 15. Hann, G.E. "Sealing Compounds and Tapes" i n "Adhesives and Sealants i n Buildings" P14. Publication 577, Building Research Institute, Washington, D.C. 1958. 16. Karpati, K . K . , Solvason, K . R . , Sereda, P . J . J. Coat Technol (1972) 44(569) 58, (1977) 49(626) 44. 17. Singh, S.M. Agarwall, L . K . Pop Plast (1974) 22(1) 26. 18. Bullman, A.R. Adhes Age (1976) 19(11) 25. 19. Callan, J.E. U.S. Pat. 3,704,196, November 28, 1972. 20. Singleton, H.M. U.S. Pat. 3,959,206, May 25, 1976. 21. Schulenberg, F. Am Paint Coat J (1977) 62(5) 32. 22. Murphy, W.T., Dake, R.B. Paint Des & Proc (1977) 17(5) 24. 23. Berger, M. Prof Decor and Coat Act (1976) (11) 38. 24. St. C l a i r , D.J., Harlan, J.T. Adhes Age (1975) 18(11) 39. 25. Aberth, W.C., Dahm, D. "Latex Caulks" i n "Proceedings of the 4th Water Borne and Higher Solids Coatings Symposium" P164, New Orleans, LA, 1977. 26. Lavelle, J.A., Frankel, L . S . Adhes Age (1977) 20(11) 41. 27. Huff, L . A . J. Paint Technol (1967) 31(7) 30. 28. Doughty, J.I., Christman, P.G. U.S. Pat. 3,654,241, A p r i l 4, 1972. 29. Overhuls, W.C., Potts, R.M. B r i t Pat. 1,392,763, A p r i l 30, 1975. 30. Weiant, D . S . , Bennett, F . E . , Velives, W.R. U.S. Pat. 3,967,429, July 6, 1976. 31. Auspack, W.R. Chem Technol (1975) 5(12) 752. 32. McCurdy, P.P. Chem Week (1976) 118(22) 29. 33. Schulenberg, F. Am Paint Coat J. (1978) 62(40) 52. 34. McCurdy, P.P. Chem Week (1979) 124(5) 36. 35. Schulenberg, F. Am Paint Coat J. (1978) 63(7) 17. 36. Brushwell, W. Am Paint Coat J. (1978) 32(51) 48. 37. Buist, J.M. "Developments i n Polyurethanes" Applied Science Publishers, Barking, Essex, England, 1978.


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38. 39. 40. 41.


42. 43.

SEYMOUR

Sealing and Caulking Compositions

Ziegler, P. Mod Paint and Coat (1978) 68(3) 68. Stapleton, J.R. U.S. Pat. 3,479,246, November 18, 1969. Peterson, E . A . , Pozniak, B.W., Smith, D.J., Yazujian, A.D. ASTM Spec Tech Publ 600 P11 (1976). Gallagher, J., Gazzito, R., Smith, D. J . Electroplat (1970) 3(1) 10. P e t t i t , G.R., P e t t i t , G.R. J Chem Soc (1978) 55 472. Schulenberg, F. Am Paint and Coat J. (1978) 63(12) 7.

RECEIVED April 2, 1979.


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Plastic Mortars, Sealants, and Caulking Compounds - ACS Publications

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