<html> <head> <title>Michael C Faudree</title><meta name="description" content="safety, polymer, polyimide, bismaleimide, BMI, triazine, quasisotropic laminates, CFRP, composites, carbon fiber reinforced polymer, sump, wing, joint, fastener, aluminum, active metal, aircraft materials, structure, environmental test, solvent soak, jet fuel, salt water, corrosion, interfacial corrosion, crevice corrosion, cathodic corrosion, galvanic circuit, battery, high performance, jet aircraft, corrosion protection, reliability, 0000n0RS, 000000Rg, FaudreeHeg, *#+J1 A'H/1J, Faudree Effect, 000000 0000, 000000"> </head> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-62561821-1', 'auto'); ga('send', 'pageview'); </script> <body topmargin='30' bottommargin='50' leftmargin='150' rightmargin='150' bgColor=white vlink="blue" alink="green"><FONT FACE="Times New Roman"><font size=4><font color=black> <h1 align="center">What is the "Plastics Corroson Phenomenon"?</h1> <p> <h2 align="left">Faudree Effect<br><br></h2> </p> <p> <h2>This was the discovery that "plastics can corrode", under galvanic action similar to that of metals,<sup>[<a href="Aviation Week Article.pdf">1</a>,<a href="http://www.researchgate.net/publication/274371115_Relationship_of_Graphite-Polyimide_Composites_to_Galvanic_Processes">2</a>, <a href="https://www.time.u-tokai.ac.jp/webopac/bdyview.do?bodyid=TD00000076&elmid=Body&lfname=link/zenbun_r_michael_christopher_faudree_20140605.pdf">3 Ph.D. Dissertation</a>]</sup> and has been referred to as the "Faudree Effect" in the industry. Previously, it was thought polymers or composites cannot corrode this way. Normally, when two dissimilar metals such as copper (Cu) and iron (Fe) are put into contact and then immersed in salt water, the iron will undergo corrosion or rust. This is called a galvanic circuit where the copper is the noble metal and the iron is the active metal, i. e., the copper is the cathode or positive (+) electrode and the iron is the anode, or negative (-) electrode. A battery is formed. It follows that plastics are made stronger by impregnating them with thin carbon fibers only a few micrometers in diameter known as carbon fiber reinforced polymers (CFRP). This is to produce materials for sports, automotive, and aircraft that are lightweight, high-strength and resistant to high temperatures. The carbon fibers act as a noble metal similar to gold (Au) or platinum (Pt). When put into contact with a more active metal, for example with aluminum (Al) in salt water the aluminum corrodes. However in early 1990, during routine aircraft solvent soak tests it was accidentally discovered imide-linked resins in CFRP composites degrade when bare composite is coupled with an active metal in salt water environments. This is because corrosion not only occurs at the aluminum anode, but also at the carbon fiber cathode (cathodic corrosion) in the form of a very strong base with a pH of about 13. The strong base is generated just above the salt water/jet fuel interface which wicks up into the confined area as in crevice corrosion. This strong base reacts with the polymer chain structure degrading and dissolving the polymer into its amide salt. Polymers affected include bismaleimides (BMI), condensation polyimides, triazines, and blends thereof. Degradation occurs in the form of dissolved resin and loose fibers. The hydroxyl ions generated at the graphite cathode attack the O-C-N bond in the polyimide structure. Although <a href="http://www.researchgate.net/publication/274371115_Relationship_of_Graphite-Polyimide_Composites_to_Galvanic_Processes">standard protection measures</a> such as glass scrim plies, sealants and inhibitors are employed, the phenonenon remained a concern. This discovery was surprising and has implications for the CFRP material used for high performance jet aircraft and resulted in design change along with patents and specifications by others contributing to aircraft reliability and safety. The phenomenon was first reported to the public in <a href="Aviation Week Article.pdf">Aviation Week & Space Technology</a> and subsequent journal article <a href="http://www.researchgate.net/publication/274371115_Relationship_of_Graphite-Polyimide_Composites_to_Galvanic_Processes">Relationship of Graphite/Polyimide Composites to Galvanic Processes. Society for the Advancement of Material and Process Engineering (SAMPE) Journal Symposium (April 15-18) (1991) 1288-1301</a>. Research is ongoing to lower the possibility of this type of corrosion.</a><br><br></h2> </p> <p> <h2 align="left">000000Rg Japanese<br><br></h2> </p> <p> <h2><FONT FACE="-3 fg">Michael C. Faudree(000000 0000)L01990 t^k0bSvj0e.sk0R0k0W0_0000000 00000k0000000n0RSsag0B000S0n0000000 00000o00 0000000L0PߘY00 0S0h00Y0j00a0000000 00000k0000000n0RSo0yr[agN Ng0wS00ё^\n0RSk0<br></h2> </p> <p> <h2 align="left">Faudree Effect Thai Language<br><br></h2> </p> <p> <h2><FONT FACE="Angsana New (QW0n00000 - 0000000 00000)"> #22#L2#"H-"*%2"-%4@!-#LB"1%'24 (2#1#H-@7H-2'2!H2(1"L) 6H9-42"C%2'4 22#- Michael C. Faudree C5 .(. 1990 DI!52#I'H2 %2*4*2!2##H-DI 2#"H-"*%2"-%4@!-#L-2@46I@+!7-144#4"2@!55H@46IB%+0DI2 2"CI@7H-D2-"H2 B"4A%I'+2B%+0H2 41 @ H Cu (-A) 1 Fe (@+%G) DI98H!4ID'ICI3@%7- @+%GG091#H-%2"@G*4! '#DI25H!5 Cu (-A) @G285H-"9HC%8H!1I*9A%0 Fe (@+%G) 1-"9HC285H!5'2!'H-D' B"-A!5H2(1"LDI2@G'A%0@+%G!5(1"LDI2@G%244#4"22DI25H*2!2#@I2CDI'H2%2*45H9*#I26I2B#* #I25H!5'2!AGA#1@*IC"2#L-C#4!2@%GI-"@H21I 6H!52@*IH2(9"L%25H@%G!2 "2H-2#!-@+G+#7-5H@#5"'H22#L-D@-#L@*#4!-%4@!-#L 1I1I@7H-%4'185H!58 2 AGA#A%0H--8+ 9!4*9 @*IC"2#L -3+I25H@GB%+0%I2"1-A (Au) +#7- A%41! (Pt) @!7H-C*H*!@I21B%+05H!5'2!'H-D'!2@ H Al CI3@%7--%9!4@5"!%-D#L -"H2D#G2!C5 .(. 1990 Michael C. Faudree DII*2"D-D!L@# 4C*2##0-2#L-D@-#L@*#4!-%4@!-#L"H-"*%2" @!7H-D!H!5*2##0-5H*2!2#19H1B%+05H!5'2!'H-D'CI3@%7- @G@ H5I@#20'H22#1#H-D!H*2!2#@46IAH5H1I'%--%9!4@5"! AH*2!2#@46IDI5H1I''-@*IC"2#L-C#9-@*AH5H!5H2 pH #0!2 13 @*AH5I0344#4"2-BI1B#*#I2-*2"-%4@!-#L @42#"H-"*%2"-%4@!-#L -%4@!-#L0*H%H- bismaleimides (BMI),2##'!1'- polyimide, triazines A%02#*!-*4H@+%H25I 2#"H-"*%2"@46IC#9-*2#%0%2"@# 4A%0@*IC"5H11-"H2+%'!F D.#- 4%D---*#I2DI5H1I'--A#DLD3%2"10 O-C-N CB#*#I2- Polyimide #22#L5I *2!2#-42"'H2-%4@!-#L*2!2#91#H-B"1%'24@ H@5"'1B%+05H!5%H2'6C Faudree Effect 2#1#H-B"1H'D*2!2#I-1I'"2#%4*4H5HI-12#"H-"*%2"-%4@!-#L 2"CI@7H-D!2!2" A!I'H22#'41"3%13@4D-"H2H-@7H-<br><br></h2> </p> <p> <h2 align="left">FaudreeHeg Mandarin Chinese<br><br></h2> </p> <p> <h2><FONT FACE="SimSun"> ُy1u5u\O(u_wvZTirM㉄vsa(WMichael C.FaudreeN1990t^Shvb/g'`e.s-N!kc0ُ/fsQN QXSP vSs, 5u\O(uSO_SZTirM,ُNё^\(Wyr[`Q NvPsaveeQv4l-NO[Pbu0ُ/fy:N5uAm5u,ܔ\O:N5ё^\\O:N;m'`ё^\,sSܔ\O:N4gbckg \O:N3gbg0 Sb_b5u`l0 TeQXe(WleQNQ_s|Svx~~~~TSX:_,b:NbN@bqwvvx~~X:_ZTir(CFRP)0ُSNcOؚ:_^,Nbؚ)nvPge0 ُyx~~v'`(N5ё^\YĞё(Au)b”(Pt)v<br></h2> </p> <p> <h2 align="right">Arabic *#+J1 A'H/1J<br><br></h2> </p> <p> <h2 align="right"><FONT FACE="Times New Roman"> G0G 'D8'G1) */GH1 'D(HDJE1 A9D C'F #HD H5AG' AJ 'D#/( AFJ)  Michael ,JE A'H/1J  AJ 9'E 1990. HC'F G0' 'D'C*4'A #FG "JECF #F *"CD 'D(D'3*JC"  HB/ */GH1 'D(HDJE1 G'! #HD'K *-/+ EF .D'D %,1'!'* :DA'FJG EE'+D) D*DC 'DE9'/F AJ 8D 81HA E9JF). 9'/)  9F/E' J*E H69 'D'*5'D '+FJF EF 'DE9'/F 'DE.*DA) E+D 'DF-'3 (Cu) H'D-/J/ (Fe) H+E E:EH1) AJ 'DEJ'G 'DE'D-)  H3J.69 'D-/J/ 'D*"CD #H 'D5/#. HG0' J3EI /'1) :DA'FJG -J+ 'DF-'3 GH 'DE9/F 'DF(JD) H'D-/J/ GH G'! #HD'K E9/FJ)  F47)  GH 'DF-'3 'DC'+H/ #H 'DB7( 'DEH,( (+) H'D-/J/ GH 'FH/  #H 'DB7( 'D3'D( (-). **CHF (7'1J). H('D*'DJ (0D #BHI 'DD/'&F 'D*J FB9 AJG' E9 #DJ'A 'DC1(HF 1BJB) %D' 9// BDJD EJC1HE*1 AJ 'DB71 'DE91HA (#DJ'A 'DC1(HF E922) 'D(HDJE1'* (CA1(). G0' GH %F*', EH'/ 0'* BH) 9'DJ) HEB'HE) D'1*A'9 /1,'* 'D-1'1). #DJ'A 'DC1(HF *9ED CE9/F F(JD) EE'+D) DD0G( (Au) #H 'D(D'*JF (Pt). 9F/E' H69* '*5'D E9 E9/F #C+1 F4'7'  9DI 3(JD 'DE+'D E9 'D#DHEFJHE (Al) AJ 'DEJ'G 'DE'D-) 'D#DHEFJHE C1H/3]. HDCF AJ #H'&D 9'E 1990  'C*4A ,JE Michael A'H/1J #F 1'*F,'* E1*(7) imide AJ 'DE1C() CA1( **-DD 9F/E' JB*1F E1C( 'D9'1J) E9/F F47) AJ (J&'* 'DEJ'G 'DE'D-). G0' (3(( 'D*"CD D' J-/+ AJ 'FH/ 'D#DHEFJHE A-3( (D #J6' 9DI 'DC'+H/ #DJ'A 'DC1(HF (4CD BHJ ,/'K E9 'DB'9/) /1,) -EH6) EF -H'DJ 13. G0G B'9/) BHJ) J*A'9D E9 GJCD 3D3D) 'D(HDJE1 'DD'%F3'FJ) 'D(HDJE1. H*4ED 'D(HDJE1'* 'DE*611) 'D*C+JA 'D(HDJEJ/'*  *1J'2JF'*  (J3E'DJEJ/J3 (BMI) HJE2, EFG. J-/+ */GH1 AJ 4CD 'D1'*F, 'DE0'( H'D#DJ'A A6A'6. G,HE #JHF'* 'DGJ/1HC3JD 'D*J *HD/* AJ 'DC'+H/ 'D,1'AJ* 'D3F/ 3-,-N AJ GJCD (HDJEJ/. G0G 'D8'G1)  #F 'D(HDJE1'* JECF 'D.6H9 DD*"CD CDA'FJ E+D 'DE9'/F B/ *E 'DE4'1 %DJG' AJ 'D-BD F*J,) "A'H/1J". *E 'D9+H1 9DI %,1'!'* -E'J) 'D*"CD 'DBJ'3J) DEF9 */GH1 'D(HDJE1 *-* E98E 'D81HA 9DI 'D1:E EF #F 'D(-H+ 'D,'1J). </body> </html>