1、Designation:F192509Standard Specification forSemi-Crystalline Poly(lactide)Polymer and CopolymerResins for Surgical Implants1This standard is issued under the fixed designation F1925;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,th
2、e 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 specification covers virgin semi-crystalline poly(L-lactide)or poly(D-lactide)homopolymer resins intended fo
3、r usein surgical implants.This specification also covers semi-crystalline resins ofL-lactide copolymerized with other bioab-sorbable monomers including,but not limited to,glycolide,D-lactide,andDL-lactide.The poly(L-lactide)or poly(D-lactide)based homopolymers and copolymers covered by this specifi-
4、cation possess lactide segments of sufficient length to allowpotential for their crystallization upon annealing.1.2 Since poly(glycolide)is commonly abbreviated as PGAfor poly(glycolic acid)and poly(lactide)is commonly abbre-viated as PLA for poly(lactic acid),these polymers are com-monly referred t
5、o as PGA,PLA,and PLA:PGA resins for thehydrolytic byproducts to which they respectively degrade.PLAis a term that carries no stereoisomeric specificity and thereforeencompasses both the amorphous atactic/syndiotacticDL-lactide based polymers and copolymers as well as the isotacticD-PLA andL-PLA moie
6、ties,each of which carries potential forcrystallization.Inclusion of stereoisomeric specificity withinthe lactic acid based acronyms results in the following:poly(L-lactide)as PLLA for poly(L-lactic acid),poly(D-lactide)as PDLA for poly(D-lactic acid),and poly(DL-lactide)as PDLLAfor poly(DL-lactic a
7、cid).1.3 This specification is applicable to lactide-based poly-mers or copolymers that possess isotactic polymeric segmentssufficient in size to carry potential for lactide-based crystalli-zation.Such polymers typically possess nominal mole frac-tions that equal or exceed 50%L-lactide.This specific
8、ation isparticularly applicable to isotactic-lactide based block copoly-mers or to polymers or copolymers synthesized from combi-nations ofD-lactide andL-lactide that differ by more than 1.5total mole percent(1.5%of total moles).This specification isnot applicable to lactide-co-glycolide copolymers
9、with gly-colide mole fractions greater than or equal to 70%(65.3%inmass fraction),which are covered by Specification F2313.Thisspecification is not applicable to amorphous polymers orcopolymers synthesized from combinations ofD-lactide andL-lactide that differ by less than 1.5 total mole percent(1.5
10、%of total moles)as covered by Specification F2579.1.4 This specification covers virgin semi-crystallinepoly(lactide)-based resins able to be fully solvated at 30C byeither methylene chloride(dichloromethane)or chloroform(trichloromethane).This specification is not applicable tolactide:glycolide copo
11、lymers that possess glycolide segmentssufficient in size to deliver potential for glycolide-basedcrystallization,thereby requiring fluorinated solvents for com-plete dissolution under room temperature conditions(seeSpecification F2313).1.5 Within this specification,semi-crystallinity within theresin
12、 is defined by the presence of a DSC(differential scanningcalorimetry)crystalline endotherm after annealing above theglass transition temperature.While other copolymeric seg-ments may also crystallize upon annealing(for example,glycolide),specific characterization of crystalline structuresother than
13、 those formed by lactide are outside the scope of thisspecification.1.6 This specification addresses material characteristics ofthe virgin semi-crystalline poly(lactide)based resins intendedfor use in surgical implants and does not apply to packaged andsterilized finished implants fabricated from th
14、ese materials.1.7 As with any material,some characteristics may bealtered by processing techniques(such as molding,extrusion,machining,assembly,sterilization,and so forth)required forthe production of a specific part or device.Therefore,proper-ties of fabricated forms of this resin should be evaluat
15、edindependently using appropriate test methods to assure safetyand efficacy.1.8 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.9 This standard does not purport to address all of thesafety concerns,if any,associated with its us
16、e.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.1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current edition approved June 1,2009.Published August 2009.Originallyapproved in 1998.Last previous edition approved in 2005 as
