1、Designation: F 624 98a (Reapproved 2003)Standard Guide forEvaluation of Thermoplastic Polyurethane Solids andSolutions for Biomedical Applications1This standard is issued under the fixed designation F 624; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the evaluation of thermoplastic poly-urethanes in both solid and
3、 solution form for biomedicalapplications. The polymers have been reacted to completionand require no further chemical processing.1.2 The tests and methods listed in this guide may bereferenced in specification containing minimum required val-ues and tolerances for specific end use products.1.3 Test
4、 values shall be stated in SI units with inch-poundunits in parentheses.1.4 Standard tests for biocompatibility are included to aid inthe assessment of safe utilization in biomedical applications.Compliance with these criteria shall not be constructed as anendorsement of implantability. Since many c
5、ompositions, for-mulations, and forms of thermoplastic polyurethanes in solidand solution forms are within this material class, the formulatoror fabricator must evaluate the biocompatibility of the specificcomposition or form in the intended use and after completionof all manufacturing processes inc
6、luding sterilization.1.5 Purchase specifications may be prepared by agreementbetween the buyer and seller by selection of appropriate testsand methods from those listed applicable to the specificbiomedical end use.1.6 This standard does not purport to address all of thesafety concerns, if any, assoc
7、iated 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:D 149 Test Method for Dielectric Breakdown Voltage andDiele
8、ctric Strength of Solid Electrical Insulating Materialsat Commercial Power Frequencies2D 150 Test Methods for ac Loss Characteristics and Permit-tivity (Dielectric Constant) of Solid Electrical InsulatingMaterials2D 257 Test Methods for dc Resistance or Conductance ofInsulating Materials2D 395 Test
9、Methods for Rubber PropertyCompressionSet3D 412 Test Methods for Vulcanized Rubber and Thermo-plastic Rubbers and Thermoplastic Elastomers-Tension3D 570 Test Method for Water Absorption of Plastics4D 575 Test Methods for Rubber Properties in Compression3D 671 Test Method for Flexural Fatigue of Plas
10、tics byConstant-Amplitude-of-Force5D 790 Test Methods for Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-als4D 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by Displacement4D 1238 Test Method for Flow Rates of Thermopla
11、stics byExtrusion Plastometer4D 1242 Test Methods for Resistance of Plastic Materials toAbrasion4D 1434 Test Method for Determining Gas PermeabilityCharacteristics of Plastic Film and Sheeting6D 1544 Test Method for Color of Transparent Liquids(Gardner Color Scale)7D 1638 Methods of Testing Urethane
12、 Foam Isocyanate RawMaterials8D 2124 Test Method for Analysis of Components in Poly-(Vinyl Chloride) Compounds Using an Infrared Spectro-photometric Technique4D 2240 Test Method for Rubber PropertyDurometerHardness3D 2857 Test Method for Dilute Solution Viscosity of Poly-mers9D 2990 Test Methods for
13、 Tensile, Compressive, and Flex-ural Creep and Creep-Rupture of Plastics9D 3137 Test Method for Rubber PropertyHydrolytic Sta-bility31This guide is under the jurisdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.11 on Poly
14、meric Materials.Current edition approved Apr. 10, 2003. Published May 2003. Originallyapproved in 1981. Last previous edition approved in 1998 as F 624 98ae1.2Annual Book of ASTM Standards, Vol 10.01.3Annual Book of ASTM Standards, Vol 09.01.4Annual Book of ASTM Standards, Vol 08.01.5Discontinued; S
15、ee 2001 Annual Book of ASTM Standards, Vol 08.01.6Annual Book of ASTM Standards, Vol 15.09.7Annual Book of ASTM Standards, Vol 06.01.8Discontinued; See 1998 Annual Book of ASTM Standards, Vol 08.01.9Annual Book of ASTM Standards, Vol 08.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959, United States.D 3418 Test Method for Transition Temperatures of Poly-mers by Thermal Analysis3E 96 Test Methods for Water Vapor Transmission of Mate-rials10F 619 Practice for Extraction of Medical Plastics11F 748 Practice for Selecting Generic Biological Test
17、 Meth-ods for Materials and Devices113. Terminology3.1 Definitions:3.1.1 chain extender(1) an active hydrogen containingcompound such as a diol or diamine used to increase themolecular weight of an isocyanate-terminated prepolymer bychemical reaction; (2) a diisocyanate used to extend a polyol-termi
18、nated polyurethane by chemical reaction.3.1.2 chain terminating agentan active hydrogen contain-ing a compound such as a monofunctional alcohol, amine, oracid that reacts with the isocyanate group of a prepolymer toprevent further chain growth.3.1.3 linear polyurethanea polymer whose backbone con-si
19、sts of urethane groups joined by hydrocarbon chains withlittle or no cross linking.3.1.4 segmented polyurethaneA family of polymers inwhich ester or ether groups, connected by hydrocarbon chains,occur as blocks that are coupled by urethane and urea groups.3.1.5 thermoplastic polyurethanelinear or se
20、gmentedpolyurethanes that can be melted for processing withoutsignificant crosslinking or degradation. They are most fre-quently synthesized by reacting diols with diisocyanates.4. Significance and Use4.1 This guide is intended to aid device fabricators in theselection of proper commercially availab
21、le polyurethane solidsand solutions for their application.4.2 The polyurethanes covered by this guide may be ther-moformed or solution cast into biomedical devices for use assurgical aids or for implantation as determined to be appropri-ate, based on supporting biocompatibility and physical testdata
22、.5. Descriptive Chemical Information5.1 DiolsDiols that can be used for biomedical applica-tions are as follows:5.1.1 Poly(oxypropylene).5.1.2 Poly(oxytetramethylene).5.1.3 Poly(caprolactone).5.1.4 Poly(ethylene adipate).5.1.5 1,4-dihydroxybutane.5.1.6 Mixture of the above diols.5.2 Difunctional Dii
23、socyanatesDifunctional diisocyan-ates that can be used are:5.2.1 Diphenylmethane 4,4-diisocyanate (MDI).5.2.2 2,4-tolylene diisocyanate (TDI).5.2.3 1,5-naphthalene diisocyanate.5.2.4 1,6-hexamethylene diisocyanate (HMDI).5.3 Chain ExtendersChain extenders that can be used are:5.3.1 Water.5.3.2 Glyco
24、ls.5.3.3 Aliphatic and aromatic diamines.5.4 Chain-Terminating AgentsChain-terminating agentssuitable for use are:5.4.1 Monofunctional alcohols, such as methanol or etha-nol.5.4.2 Monofunctional amines, such as dibutylamine or di-ethylamine.5.5 CatalystsStannous octoate is suitable for prepolymerpre
25、paration.5.6 Optional Additives:5.6.1 Pigments and dyes, such as titanium dioxide andcopper phthalocyanine blue.5.6.2 Radiopaque materials, such as barium sulfate.5.6.3 Antiblocking agents and lubricants, such as naturaland synthetic waxes.5.6.4 Optical brighteners, antioxidants, and light and heats
26、tabilizers.5.6.5 The basic polymer bought may contain, as agreedupon between the purchaser and supplier, optional adjunctsubstances required in the production of the polymer orintended end use product, provided these substances are inminor amounts and are biocompatible in the recommendedconcentratio
27、ns.5.7 Descriptive Information on Polyurethane Solutions:5.7.1 Solvent or solvents.5.7.2 Percent solids.125.7.3 Solution viscosityTest Method D 2857.5.7.4 Infrared identity testTest Method D 2124.5.7.5 Recommended diluents.5.7.6 Gardner color testTest Method D 1544.6. Processing Recommendations for
28、Fabrication (bySupplier)6.1 Drying conditions before fabrication.6.2 Suggested optimum time, temperature, and pressure forinjection molding, extrusion, or thermoforming to desiredshapes.6.3 Polymer stability at elevated temperatures of dry poly-mer in air or under an inert atmosphere.6.4 Recommended
29、 storage conditions.7. Suggested Physical Tests on a Solid Specimen or Film7.1 Tensile StrengthTest Methods D 412.7.2 Ultimate ElongationTest Methods D 412.7.3 Compression Deflection CharacteristicsTest MethodsD 575.7.4 Tensile Stress at 100, 200, and 300 % StrainTestMethods D 412.7.5 Flexural Stren
30、gthTest Methods D 790.7.6 Indentation Hardness (Durometer)Test MethodD 2240.10Annual Book of ASTM Standards, Vol 04.06.11Annual Book of ASTM Standards, Vol 13.01.12David and Staley, Analytical Chemistry of the Polyurethanes, Wiley Inter-science Publishers, 1969, p. 359.F 624 98a (2003)27.7 Flow Rate
31、 by Extrusion PlastometerTest MethodD 1238.7.8 Compression SetTest Methods D 395.7.9 Abrasion Resistance (Taber)Test Methods D 1242.7.10 Specific GravityTest Methods D 792.7.11 Hydrolytic Stability of ElastomersTest MethodD 3137.7.12 Tensile Creep and Creep Rupture TestTest MethodsD 2990.7.13 Gas Tr
32、ansmission Rate of Plastic FilmTest MethodD 1434.7.14 Water Vapor Transmission of Plastic FilmTest Meth-ods E 96.7.15 Water Absorption of PlasticsTest Method D 570.7.16 Flexural Fatigue of PlasticsTest Method D 671.7.17 Thermal AnalysesTest Method D 3418.8. Suggested Chemical Tests8.1 Isocyanate Gro
33、up ContentMethods D 1638.8.2 Amine Equivalent Weight.138.3 Ash.149. Suggested Electrical Tests9.1 Volume ResistivityTest Methods D 257.9.2 Surface ResistivityTest Methods D 257.9.3 Dielectric StrengthTest Method D 149.9.4 Dielectric ConstantTest Methods D 150.10. Suggested Biological Tests10.1 The f
34、ollowing tests are suggested for each product lineoffered for sale as a raw material for fabricating biomedicaldevices. Additional tests may be advised for certain devices asdescribed by Practices F 619 and F 748 and USP Class VItesting guidelines.10.1.1 Toxicological tests on individual batches of
35、productmay be made upon agreement between the purchaser andsupplier.11. Packaging, Labeling, and Preservation11.1 The solid polymer should be packaged in a suitablecontainer to avoid contamination and deterioration. An airtightcontainer, capable of excluding moisture, should be used whennecessary.11
36、.2 The polyurethane solutions should be packaged innonreactive, noncontaminating containers to ensure productintegrity.11.3 The product should be properly identified includingproduct and lot numbers, and, if necessary, a storage expirationdate and conditions.12. Keywords12.1 plastic surgical devices
37、/applications; polymers-surgical applications; polyurethane-medical applicationsAPPENDIXES(Nonmandatory Information)X1. RATIONALEX1.1 This guide provides definitions and a standard de-scription for thermoplastic polyurethanes in both solid andsolution forms for biomedical applications. The guide enu
38、mer-ates relevant test methods and describes generic criteria whichshould assist in developing more specific specifications forimplantable devices containing thermoplastic polyurethaneswith values and limits covering end-use applications.X2. BIOCOMPATIBILITYX2.1 The suitability of these materials fr
39、om a humanimplant perspective is dependent on the specific application.The biologic tests appropriate for the specific site, such asrecommended in Practice 748 should be used as a guideline.X2.2 No known surgical implant material has ever beenshown to be completely free of adverse reactions in the h
40、umanbody. However, long-term clinical experience of use of specificcompositions and formulations of this material class referred toin this standard has shown that an acceptable level of biologicalresponse can be expected, if the material is used in appropriateapplications.13Ibid., pp. 8789.14U.S. Ph
41、armacopeia, Vol 23, 1995.F 624 98a (2003)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and t
42、he riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision
43、of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shoul
44、dmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 624 98a (2003)4
