1、Designation:D5229/D5229M92 (Reapproved2010) Designation: D5229/D5229M 12Standard Test Method forMoisture Absorption Properties and EquilibriumConditioning of Polymer Matrix Composite Materials1This standard is issued under the fixed designation D5229/D5229M; the number immediately following the desi
2、gnation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by
3、 agencies of the Department of Defense.INTRODUCTIONConsistent evaluation and comparison of the response of polymer matrix composites to moistureabsorption can only be performed when the material has been brought to a uniform through-the-thickness moisture profile. The procedures described in Test Me
4、thod D570 and Practices D618 do notguarantee moisture equilibrium of the material. A similar, but more rigorous, procedure forconditioning to equilibrium is described by this test method, which can also be used with fluidmoisture other than water, and which, additionally, can provide the moisture ab
5、sorption propertiesnecessary for the analysis of single-phase Fickian moisture diffusion within such materials.1. Scope1.1This test method covers a procedure (Procedure A) for the determination of moisture absorption or desorption properties inthe through-the-thickness direction for single-phase Fic
6、kian solid materials in flat or curved panel form. Also covered areprocedures for conditioning test coupons prior to use in other test methods; either to equilibrium in a non-laboratory environment(Procedure B), to equilibrium in a standard laboratory atmosphere environment (Procedure C), or to an e
7、ssentially moisture-freestate (Procedure D). While intended primarily for laminated polymer matrix composite materials, these procedures are alsoapplicable to other materials that satisfy the assumptions of1.1 This test method covers a procedure for the determination of moisture absorption or desorp
8、tion properties in thethrough-the-thickness direction for single-phase Fickian solid materials in flat or curved panel form. Also covered are proceduresfor conditioning test coupons prior to use in other test methods; either to an essentially moisture-free state, to equilibrium in astandard laborato
9、ry atmosphere environment, or to equilibrium in a non-laboratory environment. Also included are procedures fordetermining the moisture loss during elevated temperature testing, as well as moisture loss resulting from thermal exposure afterremoval from the conditioning environment, such as during str
10、ain gage bonding. While intended primarily for laminated polymermatrix composite materials, these procedures are also applicable to other materials that satisfy the assumptions of 1.2.1.2 The calculation of the through-the-thickness moisture diffusivity constant in Procedure A assumes a single-phase
11、 Fickianmaterial with constant moisture absorption properties through the thickness of the specimen. The validity of the equations usedin Procedure A for evaluating the moisture diffusivity constant in a material of previously unknown moisture absorption behavioris uncertain prior to the test, as th
12、e test results themselves determine if the material follows the single-phase Fickian diffusionmodel. A reinforced polymer matrix composite material tested below its glass-transition temperature typically meets thisrequirement, although two-phase matrices such as toughened epoxies may require a multi
13、-phase moisture absorption model. Whilethe test procedures themselves may be used for multi-phase materials, the calculations used to determine the moisture diffusivityconstant in Procedure A are applicable only to single-phase materials. Other examples of materials and test conditions that maynot m
14、eet the requirements are discussed in Section 1.46.1.3 The evaluation by Procedure A of the moisture equilibrium content material property does not assume, and is therefore notlimited to, single-phase Fickian diffusion behavior.1.4The1.4 The procedures used by this test method may be performed, and
15、the resulting data reduced, by suitable automaticequipment.1This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.04 on Lamina andLaminate Test Methods.Current edition approved MayFeb. 1, 2010.2012. Published June
16、 2010.2012. Originally approved in 1992. Last previous edition approved in 20042010 asD5229/D5229M 92 (2004).(2010). DOI: 10.1520/D5229_D5229M-92R10. 10.1520/D5229_D5229M-12.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what chan
17、ges have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the offic
18、ial document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1.5 This test method is consistent with the recommendations of MIL-HDBK-17BCMH-17 Rev G (1),2which describes thedesirable attributes of a conditioning and moisture property
19、determination procedure.1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text theinch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system mustbe used independently of t
20、he other. Combining values from the two systems may result in nonconformance with the standard.1.6.1 Within the text the inch-pound units are shown in brackets.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the us
21、er of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D570 Test Method for Water Absorption of PlasticsD618 Practice for Conditioning Plastics for TestingD792 Test Meth
22、ods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD2584 Test Method for Ignition Loss of Cured Reinforced ResinsD2734 Test Methods for Void Content of Reinforced PlasticsD3171 Test Methods for Constituent Content of Composite Mate
23、rialsD3878 Terminology for Composite Materials2.2 Military Standard:MIL-B-131 Barrier Materials, Watervaporproof, Greaseproof, Flexible, Heat-Sealable43. Terminology3.1 Definitions:3.1.1 Terminology D3878 defines terms relating to high-modulus fibers and their composites. Terminology D883 defines te
24、rmsrelating to plastics. In the event of a conflict between terms, Terminology D3878 shall have precedence over the other terminologystandards.3.2 Definitions of Terms Specific to This Standard:3.2.1 If the term represents a physical quantity, its analytical dimensions are stated immediately followi
25、ng the term (or lettersymbol) in fundamental dimension form, using the following ASTM standard symbology for fundamental dimensions, shownwithin square brackets: M for mass, L for length, T for time, Q for thermodynamic temperature, and nd fornon-dimensional quantities. Use of these symbols is restr
26、icted to analytical dimensions when used within square brackets, as thesymbols may have other definitions when used without the brackets.3.2.2 accuracy criterion, nthe maximum amount of change in average moisture content for a test coupon, over the span ofthe reference time period, which is allowabl
27、e for the establishment of effective moisture equilibrium. (See also average moisturecontent, moisture equilibrium, and reference time period.)3.2.3 average moisture content, M (%), nthe average amount of absorbed moisture in a material, taken as the ratio of the massof the moisture in the material
28、to the mass of the oven-dry material and expressed as a percentage, as follows:M,%5Wi2WoWo3100 (1)D5229_D5229M-12_1where:Wi= current specimen mass, g, andWo= oven-dry specimen mass, g.(See also oven-dry.)3.2.4 Fickian diffusion, na model of material moisture absorption and desorption that follows Fi
29、cks second law, as followsin one-dimension:D5229_D5229M-12_23.2.5 glass transition temperature, TgQ, nthe approximate midpoint of the temperature range over which a reversiblechange takes place between a viscous or rubbery condition and a hard, relatively brittle condition, in an amorphous polymer,
30、orin amorphous regions of a partially crystalline polymer.2The boldface numbers in parentheses refer to the list of references at the end of this standard.3For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM S
31、tandardsvolume information, refer to the standards Document Summary page on the ASTM website.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.19111-5098,http:/dodssp.daps.dla.mil.D5229/D5229M 1223.2.5.1 Discu
32、ssionThe glass transition temperature of many polymer matrix composites is lowered by the presence ofabsorbed moisture.3.2.6 moisture, nliquid (water, jet fuel, salt water, or any other liquid) that is either diffused in relatively small quantity anddispersed through a gas as a vapor, condensed on a
33、 surface as visible dew, or present in quantity sufficient for immersion of anobject.3.2.6.1 DiscussionThe dictionary definition of moisture for this test method is extended to include not only the vapor of aliquid and its condensate, but the liquid itself in large quantities, as for immersion.3.2.7
34、 moisture concentration, c ML3, nthe absolute amount of absorbed moisture in a material expressed as the mass ofmoisture per unit volume.3.2.8 moisture diffusivity constant, DzL2T1, nthe property of a material that describes the rate at which the material absorbsor desorbs moisture.3.2.8.1 Discussio
35、nIn Fickian materials this property is relatively independent of the moisture exposure level (and thus themoisture equilibrium content material property). However, the moisture diffusivity constant is strongly influenced by temperature.Moisture diffusivity can be anisotropic; the subscript z indicat
36、es the value in the through-the-thickness direction for anisotropicdiffusion behavior.3.2.9 moisture equilibrium, nthe condition reached by a material when there is essentially no further change in its averagemoisture content with the surrounding environment. Moisture equilibrium can be either absol
37、ute or effective. Absolute moistureequilibrium requires no measurable change in moisture content, while effective moisture equilibrium allows a specified smallchange in the average moisture content of a material (the accuracy criterion) over a specified time span (the reference time period).(See als
38、o accuracy criterion, average moisture content, and reference time period.)3.2.9.1 DiscussionEffective moisture equilibrium is a satisfactory definition for most engineering applications. Unlessotherwise specified, references to moisture equilibrium in this test method mean effective moisture equili
39、brium, as quantified insection 10.2. Moisture equilibrium can also be either static, when there is no moisture transport at all across the surfaces, ordynamic, when moisture transport exists, but the net sum for the material is zero. This test method is not capable of discerningbetween these two typ
40、es of moisture equilibrium.3.2.10 moisture equilibrium content, Mm(%), nthe maximum amount of absorbed moisture that a material can contain atmoisture equilibrium for a given moisture exposure level, expressed as a percent of dry material mass. (See also moisturesaturation content.)3.2.10.1 Discussi
41、onIn polymer matrix composites, this property is relatively independent of temperature (and thus themoisture diffusivity constant material property), but it is a function of the moisture exposure level. For the purposes of this testmethod Mmis assumed to be equivalent to the average moisture content
42、 at effective moisture equilibrium, Mf.3.2.11 moisture exposure level, na measure or description of the severity of a conditioning environment in terms of theamount of liquid or vapor present. (See also moisture and relative vapor level.)3.2.12 moisture saturation content, nthe moisture equilibrium
43、content at the maximum possible moisture exposure level,wherein the material contains the greatest possible amount of absorbed moisture. (See also moisture equilibrium content.)3.2.13 oven-dry, nthe condition of a material that has been dried in accordance with Procedure D of this test method untilm
44、oisture equilibrium is achieved.3.2.14 reference time period, nthe time interval for mass measurement used to define effective moisture equilibrium in amaterial. (See also accuracy criterion, average moisture content, and moisture equilibrium. )3.2.14.1 DiscussionAsmall change in the average moistur
45、e content (the accuracy criterion) for a material during the referencetime period indicates effective moisture equilibrium.3.2.15 relative vapor level (%), nthe ratio of the pressure of a vapor present to the pressure of the saturated vapor, at the sametemperature, expressed as a percent. Applicable
46、 only to the gaseous form of a fluid. When the vapor is water vapor the term iscalled relative humidity. (See also moisture exposure level.)3.2.16 standard laboratory atmosphere, nan atmosphere (environment) having a temperature of 23 6 2C 73.4 6 3.6F anda relative humidity of 50 6 10 %.3.2.17 stand
47、ard conditioned specimen, nthe material condition of a test coupon that has reached effective moistureequilibrium at a nominal relative humidity of 50 % (considered to be a standard laboratory environment) in accordance withProcedure C of this test method.3.2.18 test temperature, nthe environmental
48、temperature used in Procedures A, B, C, or D. the environmental temperatureused in Procedures A-E, Y, Z.3.2.18.1 DiscussionThis is distinguished, for the purposes of this test method, from the environmental temperature usedduring any subsequent material evaluation testing.3.2.19 traveler coupon, na
49、surrogate coupon of the same material and thickness, and of appropriate size (but without tabs)that is used in a conditioning procedure to determine moisture content for specimen configurations (such as a tabbed mechanicalcoupon, or a coupon that does not meet the minimum mass requirement) that cannot otherwise be properly measured by this testmethod.3.3 Symbols:D5229/D5229M 1233.3.1 cmoisture concentration.3.3.2 Dzmoisture diffusivity constant in the through-the-thickness direction.3.3.3 G(T,t)moisture absorption or desorption
