Plastic Mortars - American Chemical Society

1 Plastic Mortars RAYMOND B. SEYMOUR

Downloaded by 80.82.77.83 on May 29, 2018 | https://pubs.acs.org Publication Date: November 27, 1979 | doi: 10.1021/bk-1979-0113.ch001

University of Southern Mississippi, Hattiesburg,MS39401

There is no sharp dividing l i n e between p l a s t i c mortars and sealants, but the former are usually i n situ-polymerized, highly-filled, rigid composites while the l a t t e r are usually i n situ-polymerized, f l e x i b l e polymers. Since p l a s t i c mortars do not require expensive molds, the phenolic and urea p l a s t i c motars were the pioneer p l a s t i c s . The interest i n these readily fabricated, labor-intensive, p l a s t i c s decreased as automated molding processes were developed. However, because of their excellent properties and the need to conserve energy, there i s an renewed interest i n these materials. One of the first commercial resinous motars called Asplit was prepared by mixing a silica or carbon aggregate containing a s o l i d organic acid, such as benzene sulfonyl chloride, with a l i q u i d phenolic resole resin. These mortars, of course, were the pioneer high solids composites. Many related coatings were dependent on solvent additives but because of Environmental Protective Agency (EPA) Regulations, the solvent content of these coatings are being reduced and they now approach the solvent content of p l a s t i c mortars. According to Luberoff, "everyone i s vaguely aware, that sooner or l a t e r , less v o l a t i l e will become no v o l a t i l e s . " Of course, i n essence, this means a return to the o r i g i n a l p l a s t i c mortars. Other resins, such as resorcinol and cashew nut resins, other acidic catalysts, such as p-toluene sulfonic acid and other aggregates, such as asbestos, glass flakes, and slag microfibers (PMF) have been substituted for the o r i g i n a l ingredients but basically the formulations for the r e l a t i v e l y widely used phenolic resin mortars have not changed r a d i c a l l y during more than a half century of satisfactory use. 1

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0-8412-0523-X/79/47-113-001$05.00/0 © 1979 American Chemical Society

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

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PLASTIC MORTARS, SEALANTS, AND

CAULKING COMPOUNDS

When urea-formaldehyde r e s i n s were f i r s t introduced, i t was r e l a t i v e l y easy to s u b s t i t u t e aqueous s o l u t i o n s of these r e s i n s f o r the phenolic r e s o l e r e s i n s and to o b t a i n a c o l o r l e s s urea p l a s t i c mortar by use of a c i d c u r i n g agents. While the p h e n o l i c r e s i n s mortars were used o r i g i n a l l y as a c i d r e s i s t a n t cements, the i n s i t u - p o l y m e r i z e d urea r e s i n compositions were used primari l y as adhesives and as r i g i d p l a s t i c foams.— K a o l i n i t e - f i l l e d o x a l i c acid-cured urea r e s i n s are a l s o used f o r s e a l i n g underground r o c k s - and f o r the f a b r i c a t i o n of i r r i g a t i o n p i p e . The general equations f o r these i n s i t u r e a c t i o n s are shown below: HoO


Resole p h e n o l i c or urea r e s i n s

z

Thermoset r e s i n s

The two p r i n c i p a l o b j e c t i o n s to use of p h e n o l i c r e s i n mortars, i . e . , short s h e l f l i f e and l a c k of r e s i s t a n c e to a l k a l i s were overcome by s u b s t i t u t i n g f u r f u r y l alcohol-based furan r e s i n s f o r p h e n o l i c r e s i n s . The l i q u i d phase of the o r i g i n a l furan mortar c a l l e d A l k o r was a f u r f u r y l a l c o h o l s o l u t i o n of p o l y b u t y l m e t h a c r y l a t e — which polymerized i n s i t u by the use of p-toluene s u l f o n i c a c i d which was dispersed i n the carbon f i l l e r . I n f o r mation on a p p l i c a t i o n s and chemical r e s i s t a n c e of these dark c o l o r e d resinous mortars are a v a i l a b l e , — and more i n f o r m a t i o n on furan resinous cements i s s u p p l i e d i n Chapter 2. Objections to the high exotherms i n the c u r i n g of furan resinous cements was overcome by s u b s t i t u t i n g epoxy r e s i n s f o r the l i q u i d furan prepolymer. The epoxy r e s i n s which were developed i n 1934^, were intruduced o r i g i n a l l y as resinous cements and g r o u t i n g m a t e r i a l s under the trade names of A l f a n e and Furnane i n the e a r l y 1950 s.In c o n t r a s t to the p h e n o l i c , urea and furan resinous cements, the l i q u i d epoxy r e s i n i n the epoxy cements i s cured by a r e a c t i o n w i t h a p o l y f u n c t i o n a l amine, such as polyethyleneamine or an a c t i v e polyamide (Versamid) which i s dispersed i n the carbon or s i l i c a f i l l e r as shown i n the f o l l o w i n g equation.— f

C

-C-—~~~C

C + H N^^NH 2

2

•

Polymer

These composites may be f l e x i b l i z e d by the a d d i t i o n of p o l y ethylene s u l f i d e (Thiokol) or a c a r b o x y l terminated butadiene polymer. Coal t a r may a l s o be added as an extender, p o l y v i n y l - p v i n y l p h e n o l may be used as the c u r i n g component and hard aggregates may be added to improve wear resistance.12. Epoxy r e s i n cements have been used to s e a l l e a k i n g metal gas p i p e s ^ - and f o r many c i v i l engineering a p p l i c a t i o n s , such as s t e e l w i r e - r e i n f o r c e d epoxy r e s i n c e m e n t s — and the r e c o n s t r u c t i o n of the Abu-Simbul Temple i n E g y p t . — Epoxy r e s i n cements whose p h y s i c a l p r o p e r t i e s are s i m i l a r to those of c o n c r e t e l y are discussed more completely i n Chapters 3, 4 and 5. Polyurethanes were developed as a l t e r n a t i v e s to nylon by



1.

SEYMOUR

3

Phstic Mortars

Otto Bayer i n 1 9 3 7 . T h e s e polymers, which a r e produced by the r e a c t i o n of a polyhydroxy compound and an o r g a n i c d i i s o c y a n a t e are a v a i l a b l e as f i b e r s , elastomers, moldings, foams, adhesives, and cements. One o f the pioneer polyurethane products was a wood f l o u r f i l l e d composite prepared from a h y d r o x y l terminated p o l y e s t e r and t o l y l e n e d i i s o c y a n a t e (TDI) o r i t s dimer (MDI) These composites were a l s o used i n s o l i d f u e l p r o p e l l a n t s i Z . and sealants.— However, u n t i l r e c e n t l y , the p r i n c i p a l a p p l i c a t i o n of p o l y urethanes has been as i n s i t u - p o l y m e r i z e d r i g i d and f l e x i b l e foams used f o r i n s u l a t i o n and c u s h i o n i n g , r e s p e c t i v e l y . — ' — U n l i k e the p h e n o l i c , urea and furan mortars, i n which the h i g h polymer formation i s the r e s u l t o f the c h a i n e x t e n s i o n and c r o s s l i n k i n g of a prepolymer, the f i n a l polyurethane product i s the r e s u l t o f a r e a c t i o n between h y d r o x y l and isocyanate groups as shown by the f o l l o w i n g equation: Η Ο Λ ^ ν ^ Λ ^ ^ ^ Ο Η + OCN^-~^~^W)CN

•

Polyurethane.

Almost 15 thousand tons of polyurethanes were used as binders f o r sand i n f o u n d r i e s i n 1978 but the p r i n c i p a l non-foam i n s i t u - p o l y m e r i z a t i o n of urethanes was used f o r r e a c t i v e i n j e c t i o n molding (RIM) and r e i n f o r c e d RIM (RRIM) of r e l a t i v e l y l a r g e automotive p a r t s . — Comparable techniques without the use of a molding press were used f o r the p r o d u c t i o n o f mortars and f o r m a x i l l o f a c i a l p r o s t h o d o n t i c s , i . e . , the replacement of f a c i a l features. O x a z o l i d e n e / a l i p h a t i c d i i s o c y a n a e s can be used as one pot r e s i n systems which cure i n the presence o f water a t o r d i n a r y temperatures and p r e s s u r e . — F l e x i b l e bubble-free c o a t i n g s o f polyurethanes have been produced by the use o f vacuum c e n t r i f u g a l c o a t i n g t e c h n i q u e s . — New amine c a t a l y s t s may be used t o reduce c u r i n g time of p o l y m e r i z a t i o n f o r the p r o d u c t i o n o f c a s t u r e t h a n e s . ^ A d d i t i o n a l i n f o r m a t i o n on polyurethanes s e a l a n t s i s s u p p l i e d Chapter 4. U n l i k e the polyurethanes and other p r e v i o u s l y d i s c u s s e d mortars, p o l y e s t e r cements a r e produced by a f r e e r a d i c a l c h a i n c o p o l y m e r i z a t i o n o f a l i q u i d unsaturated p o l y e s t e r and s t y r e n e . While most p o l y e s t e r composites are r e i n f o r c e d by f i b e r g l a s s , p o l y e s t e r mortars a r e u s u a l l y f i l l e d w i t h s i l i c a , c l a y or alumina t r i h y d r a t e (ΑΤΗ). P o l y e s t e r cements were o r i g i n a l l y developed as g r o u t i n g m a t e r i a l s f o r brickwork i n c h l o r i n e d i o x i d e b l e a c h i n g systems under the trade name of V i t r o p l a s t . — These products which a r e a l s o used f o r the p r o d u c t i o n of c u l t u r e d marble and l a r g e pipes are d i s c u s s e d i n d e t a i l i n Chapters 6 and 7. Since any polymeric system that w i l l harden a t o r d i n a r y temperatures i n s i t u may be used as a r e s i n o u s mortar, many other polymers have been employed f o r t h i s simple end use. Hot melt



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PLASTIC MORTARS, SEALANTS, A N D CAULKING COMPOUNDS

systems which are a l s o used as s e a l a n t s are not i n c l u d e d i n t h i s report27,28 I t i s important to p o i n t out that s i n c e these composites u s u a l l y cure at room temperature and do not r e l e a s e s o l v e n t s t h a t they conserve energy and do not c o n t r i b u t e to p o l l u t i o n . P o s s i b l y more important i s the u t i l i z a t i o n of s i l a n e and t i t a n a t e compling agents which, when p r o p e r l y s e l e c t e d and used i n optimum q u a n t i t i e s , r e s u l t i n a r e d u c t i o n i n the v i s c o s i t y of the mortar which permits the use of l a r g e r q u a n t i t i e s o f f i l l e r and assure the attainment of adequate i n t e r f a c i a l bonds between the f i l l e r and resin. These r e s i n cement systems r e q u i r e o n l y moderate c a p i t a l investment, yet can y i e l d dramatic r e s u l t s . For example, the many thousands o f cracks i n the Los Angeles C i t y H a l l produced by the 1971 earthquake were r e p a i r e d by the use of 20 thousand g a l l o n s o f an aluminum and ceramic f i l l e d epoxy r e s i n m o r t a r . — L i k e w i s e , wood whose cracks have been sealed by polyurethane mortars i s s u i t a b l e f o r continuous l a t h e c u t t i n g f o r veneer manufacture. I t i s important to p o i n t out t h a t i n s p i t e of the ease o f use, these r e s i n o u s mortars, l i k e many other chemical compositions, are t o x i c and adequate precautions must be taken to p r o t e c t the h e a l t h of the a p p l i c a t o r s . For example, the s k i n should be p r o t e c t e d from the s e t t i n g agents used i n p h e n o l i c , urea, f u r a n , and epoxy cements and adequate v e n t i l a t i o n should be provided d u r i n g the a p p l i c a t i o n of polyurethane and p o l y e s t e r cements t o prevent the i n h a l a t i o n of v o l a t i l e isocyanates and styrene r e s p e c t i v e l y . However, once they are cured, these resinous cements are not hazardous. A c t u a l l y , they are important energy conserving m a t e r i a l s o f c o n s t r u c t i o n . Literature Cited 1. 2. 3.

4. 5. 6. 7. 8. 9. 10.

Seymour, R . B . , Sosa, J . M . , Coatings and P l a s t i c s Preprints (1977), 37(2) 15. Luberoff, B.J., Chem. Tech. (1978), 8, 514. Vale, C . P . , Chapter 2, "Developments with Thermosetting P l a s t i c s , " A. Whelan and J . A . Brydson, eds., John Wiley & Sons, New York, 1975. Kalasknik, I . G . , et al., Chem Abstracts (1977), 86 156, 307. Payne, C . R . , Seymour, R . B . , U.S. Pat 2,266,049, December 26, 1944. Seymour, R . B . , Steiner, R . H . , "Plastics for Corrosion Resistant Applications," Chapter 9, Reinhold Publishing Corp. New York, 1955. Schlach, P . , Germ Pat 676,117 (1934). Seymour, R . B . , Steiner, R . H . , Chem Eng Prog, A p r i l 1953. Lee, H . , N e v i l l e Κ., "Handbook of Epoxy Resins," McGraw Hill, New York, 1967. Sommer, H . , Polymer Concr Proc Int Congr (1976), 323.


1. SEYMOUR

11. 12. 13. 14. 15. 16. 17. 18. Downloaded by 80.82.77.83 on May 29, 2018 | https://pubs.acs.org Publication Date: November 27, 1979 | doi: 10.1021/bk-1979-0113.ch001

19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

Plastic Mortars

Williamson, Β., P l a s t i c s and Rubber (1976) (654), 34. Brominski, T., Jamrozy, Z . , Kappo, J., Proc 1st Polym Concr Inst. (1979) 179. Brushwell, W., Am Paint and Coat J, p. 48, October 31, 1975. Hickey, K . B . , U.S. Gov't Res Devel Rep (1969) 69(12) 126. Bayer, O., Muller, Ε., et al., Rubber Chem and Technol (1950), 23, 812. Bayer, O., Angew Chem (1947) A59, 257. Smith, T . L . , Ind Eng Chem (1960) 52, 776. Damusis, Α., McClennan, et al., Ind Eng Chem, Prod Res Develop (1962) 1(4), 269. Saunders, J . H . , Frisch, K . C . , "Polyurethanes, Chemistry and Technology" Part I and II, Interscience Publishers, New York, 1963. Barnatt, Α., Chapter 6 "Developments with Thermosetting P l a s t i c s " A. Whelan, and J . A . Brydson, eds., John Wiley & Sons, New York, 1975. McCurdy, P . P . , Chem Week (1976) 119(24), 42. Emmons, W.D., ORPL-ACS Preprints (1974) 34(1) 731. Haines, W.N., Elastomerics (1978) 110(9) 26. Patten, W., Seefried, C . G . , Whitman, R . D . , J Paint Technol (1977) 23(13) 11. Seymour, R . B . , Steiner, R . H . , Chem Eng Progr, May 1953. Seymour, R . B . , "Hot Organic Coatings," Reinhold Publishing Co., New York, 1959. Votral, R.J., Plast Des & Proc (1977) 17(11) 42. Bullman, A . R . , Adhes Age (1976) 19(11) 25. Murray, M.A., Schultheis, V.F., Civil Eng (1977) 47(4) 67.

RECEIVED April 2, 1979.


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Plastic Mortars - American Chemical Society

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