800
700
Nonionic
600
o to 500
Surface
*:
^
Acti
10
1
400
.0 "^
300
\% OFTOTAL
200
Agents
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I0O NON IONICS
JAMES L. R A I N E Y A N D C. E. D E N O O N , J R . , Rohm & Haas Co.r Philadelphia, Pa.
1948
1949
1950
1951
1952
F i g u r e 1. Production of surface active agents
N e w sources of base materials a n d a variety of specialty applications—in c l e a n e r s , stabilizers, fertilizers, a n d therapeutic a g e n t s — p o i n t to a g r o w i n g market for nonionic surface-active agents
n p H E SHARE the nonionic surface-active •*• a g e n t s h o l d in the total surface-active market h a s grown slowly over t h e last five years, a l t h o u g h t h e volume is still small c o m p a r e d w i t h t h e anionics. Of course, nonionics c a m e into commercial u s e m o r e recently than either t h e cationics or t h e anionics. Nonionics, although used in household applications ( w h e r e the a n ionics h a v e h a d a tremendous g r o w t h ) , h a v e h a d their biggest growth in a w i d e variety of specialty applications. T h e base materials for manufacturing nonionic surface-active agents a r e ethylene oxide, e t h y l e n e oxide derivatives s u c h as polyethylene glycol a n d diethanolamirie, glycerol, a n d sorbitol. These a r e used in making t h e hydrophilic part of V O L U M E
3 1,
NO.
4 4
*
the molecule. T h e principal hydrophobe sources are alkylphenols, tall oil, longchahn fatty a c i d s and f a t t y amides, straight and branched chain alcohols a n d amines, and b r a n c h e d chain m e r c a p t a n s . E t h y l e n e o x i d e is ordinarily used by direct alkaline-catalyzed a d d i t i o n of ethylene oxide to t h e alklyphenol, carboxylic acid, m e r c a p t a n , or o t h e r base material. S o m e processors w h o a r e n o t equipped to h a n d l e ethylene o x i d e p r e p a r e estert y p e nonionics by esterification of fatty acids with polyethylene glycol. Sorbitol is used to prepare f a t t y acid esters of sorbitan, w h i c h are either sold as such or a r e further modified by reaction with ethylene oxide. T h e p r i n c i p a l glycerol derivatives are the m o n o - a n d di-glycer-
N O V E M B E R
2,
19 5 3
ides, which, because of their similarity to natural fats, are approved for some food uses. Ethanolamines are used to prepare the " a m i d e condensates" which are made from one mole of fatty acid and one or more moles of an ethanolamine. T h e h y d r o p h o b e portion of the molecule can b e derived either from petroleum or from naturally occurring fats or oils. Propylene a n d isobutylene from the cracking of petroleum are polymerized to give longchain monoolefins which are used to alkylate phenol. T h e principal alkylphenols which go into the nonionic detergents are octylphenol, nonylphenol, and dodeeylphenol, derived from diisobutylene, tripropylene and tetrapropylene, respectively. Another method for use of t h e olefin is 4521
100* •—1 95 90 85 80 75 70 65 60 55 50 45 40 35 30
h—Mh
w
m i
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119'16
19 47
19'*8
1949
I k jr 1950
J^—
1952
1951
195
Figure 2. Price history of a typical nonionic d e t e r g e n t
the addition of h y d r o g e n sulfide to the double bond to produce a niercaptan which is then treated with ethylene oxide to produce alkylthioethers of polyethylene glycol. Triisobutylene and propylenebutylene polymer averaging 12 carbon atoms are used here. nr..u ~:i / ..
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~£ r„i.i... — ; J „
1
resin acids obtained as a byproduct from the paper industry in t h e sulfate pulping process ) has attained great importance as a base material, primarily because of its low cost. Low tallow prices should encourage more extensive use of t h e longchain fatty acids and their derivatives as base materials for nonionics. Another recently developed group of products gets its hydrophobic backbone* from the polymerization of propylene oxide. This unexpected effect can be rationalized by the fact that the e t h e r linkages of polypropylene glycol are shielded by methyl groups on adjacent carbon atoms. Hence, t h e chain is hydrophobic, rather than hydrophilic. Nonionics A r e S t a b l e a n d Effective In A c i d s , Bases, a n d H a r d W a t e r
In general, nonionics have a number of important advantages. They are stable
About
the
and effective in acids, bases and hard water. T h e y can be m a d e and shipped conveniently in anhydrous, salt-free form. This avoids drying costs or excessive freight charges. Recent developments have improved greatly the batch to batch uniformity o f these agents and produce materials wTiich are water-white a u u essentially odorless. An important factor in the growth ol nonionic- surface-active agents is t h e d e velopment of new products aimed at specific uses. T r i e ease with which t h e h y d r o phil-hydrophobe ratio can b e controlled is responsible for this trend, which is likely to continue. For example, the manufacture of emiilsifiable concentrates of agricultural insecticides h a s been an important outlet f o r nonionics since the introduction of I DDT in 1943. New products have been developed in the last 10 years to give more efficient performance with various natural waters and to h a n d l e t h e new toxicants which have come on the market. Recently, nonionic emulsifiers blended witfi anionic surface-active agents have c a p t u r e d much of this market. Their particular advantages are good stability, case of emulsification, and compatibility with a wide range of natural waters. In
Nor.icr.ics—The " A H Surface !n Industrial C l e a n i n g Field
Cleaners"'
I n the industrial cleaning field nornionics have been called "all surface cleansers." Recent work has shown t h a t a nurraber of anionic surfactants clean glass welO b u t are ineffective on metals, a n d in som-e cases, actually promote soil redepositiora.. Similarly, the cationics promote soil rerueposition on glass. The nonionics, h o w ever, are effective in cleaning both t y p e ^ of substrate, apparently because they a r ^ adsorbed in such a way as to promote w e t ting of the surface b y the aqueous solution* Modifications h a v e been developed t < give increased compatibility with caustii< builders, lower foam, and better r i n s i n g T h e low foam feature has been particu* larly important in t h e acceptance of norm ionic detergents in t h e household laundeir ing field, since in certain types of machines a controlled moderate foam gives better mechanical action than a heavy suds. At:
Authors-
C. E. Denoon, Jr., heads the special products department of Rolim & Haas Co., which he joined i n 1945 to d o sales work. His previous industrial experience was obtained with t h e Du Pont C o . a n d Landers Corp., where he did research. H e was educated at t h e University of Richmond a n d the University of Illinois, receiving a Ph.D, i n organic chemistry from t h e latter in 1938. 4522
t h e textile processing field, the older type=s of ionics have been modified t o give, iw: one case, a product designed for the scouring of wool and, in another, a p r o d u c t d e signed particularly for scouring of cottosr goods.
J a m e s L. Rainey, h e a d of one of the synthesis laboratories at Rohm & Haas Co., has several patents on surface active agents and aminoplasts to his credit. H e received a B.S. from the University of Illinois in 1935 and a Ph.D. in organic chemistry from the University of Wisconsin in 1938, a n d his entire industrial career has been spent with Rohm & Haas.
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