ASTM_F_1634_-_95_2008.pdf

Designation:F163495(Reapproved 2008)Standard Practice forIn-Vitro Environmental Conditioning of Polymer MatrixComposite Materials and Implant Devices1This standard is issued under the fixed designation F1634;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 practice covers two procedures for conditioningnon-absorbable polymer matrix composite(PMC)materialsand implant devices in a liquid environment to obtain a state ofsaturation.1.2 The purpose of this practice is to standardize methodsand reporting procedures for conditioning PMC materials andimplant devices(PMC specimens)in a user selected liquidenvironment prior to conducting subsequent tests.It is not thepurpose of this practice to determine the diffusion coefficientsor actual saturation levels of a given liquid into the materialsand devices.For these determinations,other procedures,suchas Test Method D5229/D5229M,may be followed.1.3 Diffusion of liquid into a solid material is a slowprocess.While the time necessary to achieve saturation at 37Cmay be sufficiently short for thin specimens,such as fracturefixation plates,it may be prohibitively long in thick sections,such as femoral components for hip arthroplasty.However,thediffusion process may be accelerated at an elevated tempera-ture.Consequently,two separate procedures(ProceduresAandB)are presented in this practice.Procedure A covers exposingthe specimen to the desired conditioning environment at 37C.Procedure B prescribes a method to accelerate the diffusionprocess by conditioning the specimen at a selected elevatedtemperature.1.4 This practice does not specify the test environment to beused for conditioning.However,the pH value of immersionliquid shall be maintained at 7.4 6 0.2 to simulate the in vivoenvironment.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD756 Practice for Determination of Weight and ShapeChanges of Plastics UnderAccelerated Service Conditions(Withdrawn 1998)3D3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite Materials3.Terminology3.1 Definitions:3.1.1 cumulative moisture content,Mt(%),nthe amountof absorbed moisture in a material at a given time t,expressedas a percentage of the weight of absorbed moisture divided bythe initial specimen weight,as follows:Mt,%5Wi2 WbWb3100(1)where:Wt=current specimen weight,g,andWb=initial(baseline)specimen weight at t=0 and stan-dard laboratory atmosphere,g.3.1.2 liquid,nwater,saline solution,calf serum,or anyother liquid solution that is used to condition PMC specimens.3.1.3 nominal saturated moisture content,Ms(%)an ap-proximation of the amount of moisture absorbed by a specimenat saturation,expressed as a percentage of the weight ofabsorbed moisture at approximate saturation divided by theinitial specimen weight,as follows:1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Aug.1,2008.Published August 2008.Originallyapproved in 1995.Last previous edition approved in 2000 as F1634 95(2000).DOI:10.1520/F1634-95R08.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Ms,%5Ws2 WbWb3100(2)where:Ws=specimen weight at approximate saturation,g,andWb=initial(baseline)specimen weight at t=0 and standardlaboratory atmosphere,g.3.1.4 standard laboratory atmosphere,n a laboratoryatmosphere having a temperature of 23 6 2C and a relativehumidity of 50 6 10%.4.Summary of Test Method4.1 In Procedure A,a specimen is immersed in a liquid bathat 37 6 1C with a pH value of 7.4 6 0.2.4.2 In Procedure B,conditioning occurs in a liquid bath at aselected elevated temperature.4.3 Weight change is monitored over time until specimensreach the nominal moisture saturation content.4.4 Keep specimens in the conditioning bath for storageprior to s