ASTM_D_8380_-_21.pdf

Designation:D838021Standard Test Method forDry Abrasion Resistance of Hydrophobic and OmniphobicCoatings1This standard is issued under the fixed designation D8380;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes a procedure for evaluatingdry abrasion resistance of a thin hydrophobic or omniphobiccoating,or both.The coating is typically less than 100 nm thickand is applied to a planar,glass substrate by applicationmethods including,but not limited to,physical vapor deposi-tion(PVD),dip,or spray.1.2 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard with the exception of angular measurement which arereported in degrees.NOTE1This test method measures a static contact angle and is notequivalent to Test Method C813 which measures an advancing contactangle.NOTE2Test Method D4060 is not applicable to hydrophobic andomniphobic coatings because the molecular monolayer does not generallyresult in a detectable weight change to the specimen after subjecting it toabrasion.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C813 Test Method for Hydrophobic Contamination on Glassby Contact Angle MeasurementD16 Terminology for Paint,Related Coatings,Materials,andApplicationsD1193 Specification for Reagent WaterD4060 Test Method for Abrasion Resistance of OrganicCoatings by the Taber AbraserD5946 Test Method for Corona-Treated Polymer Films Us-ing Water Contact Angle MeasurementsD7490 Test Method for Measurement of the Surface Tensionof Solid Coatings,Substrates and Pigments using ContactAngle MeasurementsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsDefinitions used in this test method are inaccordance with Terminology D16,unless otherwise specified.3.2 Definitions of Terms Specific to This Standard:3.2.1 abrasion cycle,nin abrasion testing,one or moremovements of the abradant across a material surface,or thematerial surface across the abradant,that permits a return to itsstarting position;for this test method,one abrasion cycle is acomplete back and forth motion.3.2.2 static contact angle,(degrees),nthe angle be-tween the substrate surface and the tangent line drawn to thedroplet surface at the three-phase point,when a liquid drop isresting on a plane solid surface(see Fig.1).4.Summary of Test Method4.1 The coating is applied in a uniform thickness to planarglass panels and,after curing,the surface is abraded using areciprocating rubbing action under controlled conditions ofpressure and abrasive action.Droplets of type IV grade ofreagent water are placed on the surface of the specimen,andthe contact angle values are measured and then averaged.Thetest specimen is subjected to abrasion in the same location,until the failure threshold has been reached.Abrasion resis-tance is assessed by measuring the water contact angle withinthe abraded area of the test specimen and reporting the numberof abrasion cycles.NOTE3A glass substrate was selected because the abradant will wear1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Jan.1,2021.Published February 2021.DOI:10.1520/D8380-21.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1the coating before sig