Advancing Know-How Paints Bright Future for Corrosion Engineering
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THE CHEMICAL WO^'O THIS WEEK Discussing corrosion problems between sessions were (left to right): F. J LeFebvre, Metropolitan New York Section of NACE; T. S. Zajac, chairman of NACE s technical practices committee; H. H. Uhlig, MIT; J. E. Draley, corrosion engineer with AEC's Argonne National Laboratory; and Κ. Η. Roll, Metropolitan New York Section of NACE C&EN REPORTS: National Association of Corrosion Engineers Advancing Know-How Paints Bright Future for Corrosion Engineering Degrees in corrosion engineering, progress in corrosion protection foreseen less general portion of the program George Scat chard of MIT explained his formulae for calculating the general thermody- namic interactions between molecules in protein solutions. He pointed out that protein molecules in solution are almost always surrounded by a squadron of small ions which he compared to a fleet of destroyers protecting a battleship, and he said that in order to understand the inter- actions between the proteins it is first necessary to understand their interactions with the»se small ions. He said that long range effects can usually be ignored and the interactions treated as chemical com- binations. He approached the problem by determining the classical first associa- tion constant which is the sum of the in- trinsic association constants for all of the possible sites in the molecule. He warned that the presence of a buffer in the solu- tion seriously complicates the calculations. Electrophoresis Studies. The power of electrophoresis techniques in studying the association of proteins with other ions was ably demonstrated by Robert Alberty of the University of Wisconsin. He said that both the strength of the protein bonding as well as the size of the aggregates could be determined more-or-lcss quantitatively by these techniques. Strongly bonded complexes show greater change in their rate of migration than combinations that are only loosely associated according to Alberty. Similarly large complexes mi- grate more slowly than small ones. Alberty also said that the electrophoresis tech- nique offers the only method for study of complexes formed by proteins with maero- molecuUir ions, nucleic acids, polysac- charides, and other proteins, an important factor in investigating the reactions of blood plasma substitutes in the body. Dye-Protein Bonding. An interest in the reactions of the blood plasma substi- tutes was also implied in the contribu- tion of Gerald Oster of Brooklyn Poly. Almost all of these substances are included in the class of water-soluble polymers with which his investigation was con- cerned. Oster reported that several of the anionic dyes with which he worked bind strongly to native serum albumin and to polyvinyl pyrrolidone (1VP). However, he said, the binding force with albumin decreases at about pH 9 while the bind- ing with PVP is independent of pi I. Various other proteins he said, will bond with these dyes when denatured but the bonding power decreases with enzymatic degradation. He said that this loss in binding power can be used to fol- low the process of degradation through a colorimetric technique. A further investigation with the fluo- rescein series of dyes reveaLed that binding decreases with increasing polarizability of the dye which suggested to Oster that van der Waals forces are involved in the association. 1856 NEW YORK.-The time will come when corrosion engineering will be a required course in all engineering schools, H. H. Uhlig, head of MIT's corrosion laboratory, concluded at the joint meeting here April 2:3 of the Northeast Region and Metro- politan New York Section, National Asso- ciation of Corrosion Engineers. In out- lining the future of affairs concerning cor- rosion, Dr. Uhlig predicted that the cor- rosion engineer will take his place with the chemical engineer and the metallur- gist; there will be degrees offered in cor- rosion engineering just as the University of Michigan now has a new degree in materials engineering. Pore-Free Coatings. A pore-free, thin nickel coating will be an accomplishment of the future, though is not in sight now, Uhlig said. There is also the possibility that zinc or zinc-copper alloys will sub- stitute for nickel, but first a better lac- quer to cover them must be developed. Nickel-tungsten and nickel-molybdenum alloys, of the Hastelloy type, will have a good future if they can be made pore- iree, and will be able to hold up against hydrochloric, sulfuric, and other acids. Titanium-Clad Steel. Another im- portant possibility, the spe'aker noted, is titanium-clad steel, which is so far too expensive, a main advantage being that titanium resists pitting under influence of chlorides and resists stress corrosion crack- ing. It will be applied to hot water tanks, piping, chemical vessels, and the like. Zinc, cadmium, and aluminum may be CHEMICAL used as sacrificial coatings. Aluminum- clad copper, if pore-free, can resist nitric acid. Aluminum on steel will be effective, particularly in industrial atmosphere, for resisting sulfur. However the aluminum must be used in extremely pure state. Coating for Protection. Wash primers seem to have a future for protection against corrosion, he observed, as they are one-operation coatings and save labor. A great future lies in better paints in which progress has been slow. For a paint twice as good as that presently available, con- sumers can afford to pay four times as much as now. Teflon has phenomenal resistance to all corrosive media, Uhlig declared. It is now expensive and difficult to bond but this will be worked out and will be used for coating piping, tanks, and the like. Glass coatings also have a good future because they are cheap and, though porous, can be used with cathodic protection. We will see more glass-lined vessels and piping. We will have better inhibitors—nitrides and chromâtes when we understand them better. Improve Environment. Progress will be rapid in providing better environment where metals will not corrode, he pre- dicted. Engineers will boil out oxygen from waters used in boilers, since five parts per million of oxygen is harmful. In fact vacuum de-aerators will be used ex- tensively in industry and municipalities so that the household water-bearing metal equipment will no longer corrode. AND ENGINEERING NEWS
Transcript of Advancing Know-How Paints Bright Future for Corrosion Engineering
THE CHEMICAL W O ^ ' O THIS WEEK
Discussing corrosion problems between sessions were (left to r igh t ) : F . J LeFebvre, Metropolitan New York Section of NACE; T. S. Zajac, chairman of NACE s technical practices committee; H. H. Uhlig, MIT; J. E . Draley, corrosion engineer with AEC's Argonne National Laboratory; and Κ. Η. Roll, Metropolitan New York Section of N A C E
C&EN REPORTS: National Association of Corrosion Engineers
Advancing K n o w - H o w Paints Bright Future for Corrosion Engineering
Degrees in corrosion engineering, progress in corrosion protection foreseen
less general portion of the program George Scat chard of MIT explained his formulae for calculating the general thermodynamic interactions between molecules in protein solutions. He pointed out that protein molecules in solution are almost always surrounded by a squadron of small ions which he compared to a fleet of destroyers protecting a battleship, and h e said that in order to understand the interactions between the proteins it is first necessary to understand their interactions with the»se small ions. He said that long range effects can usually be ignored and the interactions treated as chemical combinations. He approached the problem by determining the classical first association constant which is the sum of the intrinsic association constants for all of the possible sites in the molecule. He warned that the presence of a buffer in the solution seriously complicates the calculations.
Electrophoresis Studies. The power of electrophoresis techniques in studying the association of proteins with other ions was ably demonstrated by Robert Alberty of the University of Wisconsin. He said that both the strength of the protein bonding as well as the size of the aggregates could be determined more-or-lcss quantitatively by these techniques. Strongly bonded complexes show greater change in their rate of migration than combinations that are only loosely associated according to Alberty. Similarly large complexes migrate more slowly than small ones. Alberty also said that the electrophoresis technique offers the only method for study of complexes formed by proteins with maero-molecuUir ions, nucleic acids, polysaccharides, and other proteins, an important factor in investigating the reactions of blood plasma substitutes in the body.
Dye-Protein Bonding. An interest in the reactions of the blood plasma substitutes was also implied in the contribution of Gerald Oster of Brooklyn Poly. Almost all of these substances are included in the class of water-soluble polymers with which his investigation was concerned. Oster reported that several of the anionic dyes with which he worked bind strongly to native serum albumin and to polyvinyl pyrrolidone (1VP). However, he said, the binding force with albumin decreases at about pH 9 while the binding with PVP is independent of pi I.
Various other proteins he said, will bond with these dyes when denatured but the bonding power decreases with enzymatic degradation. He said that this loss in binding power can b e used to follow the process of degradation through a colorimetric technique.
A further investigation with the fluorescein series of dyes reveaLed that binding decreases with increasing polarizability of the dye which suggested to Oster that van der Waals forces are involved in the association.
1856
N E W YORK.-The time will come when corrosion engineering will be a required course in all engineering schools, H. H. Uhlig, head of MIT's corrosion laboratory, concluded at the joint meeting here April 2:3 of the Northeast Region and Metropolitan New York Section, National Association of Corrosion Engineers. In outlining the future of affairs concerning corrosion, Dr. Uhlig predicted that the corrosion engineer will take his place with the chemical engineer and the metallurgist; there will b e degrees offered in corrosion engineering just as the University of Michigan now has a new degree in materials engineering.
Pore-Free Coatings. A pore-free, thin nickel coating will be an accomplishment of the future, though is not in sight now, Uhlig said. There is also the possibility that zinc or zinc-copper alloys will substitute for nickel, but first a better lacquer to cover them must be developed. Nickel-tungsten and nickel-molybdenum alloys, of the Hastelloy type, wil l have a good future if they can be made pore-iree, and will be able to hold up against hydrochloric, sulfuric, and other acids.
Titanium-Clad Steel . Another important possibility, the spe'aker noted, is titanium-clad steel, which is so far too expensive, a main advantage being that titanium resists pitting under influence of chlorides and resists stress corrosion cracking. It will b e applied to hot water tanks, piping, chemical vessels, and the like.
Zinc, cadmium, and aluminum may be
C H E M I C A L
used as sacrificial coatings. Aluminum-clad copper, if pore-free, can resist nitric acid. Aluminum on steel will b e effective, particularly in industrial atmosphere, for resisting sulfur. However the aluminum must be used in extremely pure state.
Coating for Protection. Wash primers seem to have a future for protection against corrosion, he observed, as they are one-operation coatings and save labor. A great future lies in better paints in which progress has been s low. For a paint twice as good as that presently available, consumers can afford to pay four times as much as now.
Teflon has phenomenal resistance to all corrosive media, Uhlig declared. It is now expensive and difficult to bond but this will b e worked out and will b e used for coating piping, tanks, and the like. Glass coatings also have a good future because they are cheap and, though porous, can be used with cathodic protection. W e will see more glass-lined vessels and piping. We will have better inhibitors—nitrides and chromâtes when w e understand them better.
Improve Environment. Progress will b e rapid in providing better environment where metals will not corrode, he predicted. Engineers wi l l boil out oxygen from waters used in boilers, since five parts per million of oxygen is harmful. In fact vacuum de-aerators will b e used extensively in industry and municipalities so that the household water-bearing metal equipment will no longer corrode.
A N D E N G I N E E R I N G N E W S
