1、Designation: D 3632 98 (Reapproved 2004)Standard Test Method forAccelerated Aging of Adhesive Joints by the Oxygen-Pressure Method1This standard is issued under the fixed designation D 3632; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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 test method describes how to estimate the relativeresistance to deterioration of adhesive fi
3、lms and adhesive-bonded joints placed in a high-pressure oxygen environment.The instructions include both wood-to-wood and wood-to-metal joints as well as free film of adhesive. The effects ofchemicals such as fire retardants, preservatives, or woodextractives, can be evaluated by using materials co
4、ntainingthese chemicals for adherends.1.2 This test method is primarily intended for elastomer-based construction adhesives, but is also applicable to othertypes of adhesives that may be susceptible to oxygen degrada-tion. This accelerated test does not correlate exactly with thenatural aging of the
5、 adhesive because of the varied conditionsof natural aging and the absence of factors such as moistureand stress. The results of this accelerated test are onlycomparative and must be evaluated against the performance ofbonded joints whose natural and accelerated aging character-istics are known.1.3
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 Docum
7、ents2.1 ASTM Standards:2D 143 Test Methods for Small Clear Specimens of TimberD 454 Test Method for Rubber Deterioration by Heat andAir PressureD 572 Test Method for RubberDeterioration by Heat andOxygenD 573 Test Method for RubberDeterioration in an AirOvenD 907 Terminology of AdhesivesD 2339 Test
8、Method for Strength Properties of Adhesives inTwo-Ply Wood Construction in Shear by Tension Loading3. Terminology3.1 DefinitionsMany definitions in this test method aredefined in Terminology D 907.4. Summary of Test Method4.1 This test method entails subjecting specimens withknown physical propertie
9、s to a controlled aging environmentfor specific time periods, then observing the physical propertiesagain and noting any changes. The controlled environmentconsists of elevated temperature (70C) (158F) and oxygen atelevated pressure 2.07 MPa (300 psi).4.2 Three types of test specimens are offered. T
10、he partyrequesting the adhesive evaluation will choose the type ofspecimen to be used.Specimen Type ConfigurationPhysical PropertyTestedA wood-to-wood lap shear strengthB wood-to-metal lap shear strengthC unsupported film flexibility4.3 Three different oxygen-pressure aging exposures areoffered. Use
11、 any exposure with any of the above specimens.The party requesting the adhesive evaluation will choose theexposure to which the specimens are subjected.4.3.1 Constant exposure for 500 h with a single test of thephysical property at the end of 500 h.4.3.2 Constant exposure for 1000 h with a single te
12、st of thephysical property at the end of 1000 h.4.3.3 Constant exposure for up to 1000 h with a series oftests of the physical property after 200, 400, 600, 800, and1000 h.5. Significance and Use5.1 This test method is useful to the adhesive manufacturerin research and development or in manufacturin
13、g control. Theresults are also used for specification acceptance or as a guidein adhesive selection.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.70 on ConstructionAdhesives.Current edition approved April 1, 2004. P
14、ublished April 2004. Originallyapproved in 1977. Last previous edition approved in 1998 as D 3632 98.2For 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 D
15、ocument Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 The provisions for testing bonded specimens as well asfree films are made for two purposes. First, it is possible for aninteraction to occur
16、between oxygen and chemicals or degra-dation products that may affect the degradation of the bondedjoints strength. Second, some increase in strength due tooxidative crosslinking may not be detrimental in a bondedassembly and in fact may be beneficial. Adhesives of thisbehavior are not satisfactoril
17、y tested by a film flexibility test.5.3 Some users of this test method will be most interested inthe performance of the bonded joint; some will be mostinterested in the performance of the adhesive. In the latter case,it is important to note that the true variance (error mean square)of the strength o
18、f the adhesive may be obscured when thetested control specimens or the tested aged specimens showwood failure.5.4 Conflict of ProcedureIf the procedures of this testmethod conflict with those of detailed product specifications ormanufacturers use instructions for a particular material, thenuse the l
19、atter.6. Apparatus6.1 Oxygen-Pressure VesselThe specifications for theoxygen-pressure vessel described in 6.1.1.1 through 6.1.1.8 arethe same as those described in Test Method D 572. Adequatesafety provisions are important when heating oxidizable or-ganic materials in oxygen, since the rate of react
20、ion maybecome very rapid and very high pressures may develop.Heating these materials is especially dangerous when a largesurface area is exposed. If the same equipment is used for theoxygen-pressure test as for the air-pressure heat test (TestMethod D 454), be careful and check to see that the therm
21、o-static controls are set properly because the specimens mayreact with oxygen very rapidly at the temperature of theair-pressure heat test. Fluids acceptable as heating media forone test may be hazardous when used for the other test.6.1.1 Use on oxygen-pressure chamber consisting of a metalvessel de
22、signed to retain an internal atmosphere of oxygen gasunder pressure, with provisions for placing specimens within itand for subjecting the entire chamber to controlled uniformtemperature. Because of the superior temperature control andheat transfer, a metal vessel completely immersed in a liquidmedi
23、um is recommended for referee tests. Ensure that theapparatus conforms to the following requirements:6.1.1.1 The chamber can be any size; however, it must belarge enough so that the specimens can be hung within itvertically, without crowding them, letting them touch eachother, or letting them touch
24、the sides of the chamber.6.1.1.2 The source of heat is optional, but a location outsideof the aging chamber itself is required.6.1.1.3 The heating medium is optional. Water, air, or otherfluids that will not ignite when oxygen is present may be used.Water has an advantage because it transfers heat r
25、apidly and isnoncombustible. When using air for the heating medium,thoroughly circulate the heated air by mechanically agitating it,and use baffles as needed to prevent local overheating and deadspots. Do not use oils or other combustible fluids as heatingmedia for this test because they are extreme
26、ly hazardous whenoxygen is present.6.1.1.4 Use a thermostat to control automatically the tem-perature of the heating medium.6.1.1.5 Record the temperature automatically throughoutthe test period. If the pressure chamber is completely im-mersed, use the temperature of the heating medium as thetempera
27、ture of the pressure chamber. Place the sensing elementclose to the temperature-measuring device but not touching thepressure chamber. If the pressure chamber is not completelyimmersed in the heating medium, place the sensing element ina thermometer well that extends into the pressure chamber. Fillt
28、he thermometer well with enough water to cover the elementso that heat will transfer easily. If a comparison has been madeand it has been confirmed that the temperature of the oxygenwithin the chamber is the same as the temperature of theheating medium, it is permissible to take the temperature in t
29、heheating medium instead of in the thermometer well. Whenusing air as the heating medium, check the temperature invarious parts of the oven to determine that the oven is heatingevenly. In any case, verify the recorded temperature bychecking with a temperature-indicating device whose sensingelement i
30、s directly exposed to the oxygen within the pressurechamber.6.1.1.6 Maintain positive, rapid, and complete circulation ofthe heating medium so as to ensure accurate, uniform heating.6.1.1.7 The pressure chamber should have a reliable safetyvalve or rupture diaphragm set for release at 3.448 MPa (500
31、psi) pressure.6.1.1.8 Do not expose any copper or brass parts to theatmosphere nor use them in the pressure chamber or the tubingor valves leading to it.6.2 Testing Machine for Lap Shear Strength TestsThetesting machine specifications described in 6.2.1 are the sameas those described in Test Method
32、D 2339.6.2.1 Use a testing machine capable of maintaining aconstant rate of loading of 42 to 74 N/s (600 to 1000 lbf/min)or a constant rate of crosshead travel of 0.020 mm/s (0.050in./min) 6 25 %. Use a testing machine with suitable grips andjaws so that the specimen can be gripped tightly and held
33、inalignment as the load is applied. Fig. 1 shows grips and jawsthat have been found satisfactory. Place the testing machine inan atmosphere that will not noticeably alter the moisturecontent of the specimens developed under the conditionsprescribed in 10.2.6.3 Air Curing and Drying OvenExcept for so
34、me modi-fication, the oven specifications described (in 6.3.1 through6.3.9) are the same as those described in Test Method D 573.6.3.1 Use an oven whose interior size is (minimum) 0.40 m3(1 ft3) to (maximum) 1.33 m3(36 ft3) or any equivalentvolume.6.3.2 Suspend the specimens vertically without letti
35、ng themtouch each other or the sides of the oven.6.3.3 The temperature variation in various parts of the ovenshall not be allowed to exceed 2C (4F).6.3.4 For the heating medium, use air circulated within thechamber at atmospheric pressure.6.3.5 Any source of air may be used, if it is located in the
36、airsupply outside of the chamber itself.D 3632 98 (2004)26.3.6 Install a thermometer in the upper central portion ofthe chamber, near the center of the specimens, to measure theactual temperature.6.3.7 Use a thermostat to control the temperature automati-cally.6.3.8 Circulate the heated air througho
37、ut the oven bymechanically agitating it. When using a motor-driven fan, theair must not come in contact with the fan motor brushdischarge because there is danger of ozone forming.6.3.9 Use baffles where they are needed to prevent localoverheating and dead spots.7. Materials7.1 Adhesive, the adhesive
38、 to be tested.7.2 Wood for wood-to-wood and wood-to-metal specimens,rotary cut, sliced or sawn and jointed veneers 3.2 to 6.4 mm (18to14 in.) thick, shall be free of defects such as knots, cracks,short grain, or any discolorations or soft spots indicative ofdecay. The species to be used will be deci
39、ded by the adhesivemanufacturer or by the party requesting these tests. Generallya high-density wood such as Douglas-fir, hemlock, southernpine, or yellow birch is desirable.7.3 Metal for wood-to-metal specimen dimensions be 1.6to 3.2 mm (116 to18 in.) thick. The metal will be selected by theadhesiv
40、e manufacturer or by the party requesting the test,except that the metal used shall not be reactive as, for example,magnesium plate.7.3.1 The mill finish or chemical treatment of the surfaceshould be the same as the material expected to be bonded inservice with finish or surface treatment to be sele
41、cted by theadhesive manufacturer or by the party requesting the test,except that lubricants or other combustible materials shall beremoved from the surface by solvent cleaning before exposurein the oxygen-pressure vessel.8. Sampling8.1 Sampling MethodWhen several test specimen panelsare made or film
42、s cast and groups of individual specimens areaged for different time intervals, mix all the specimens in a boxand draw at random from the box for assignment to a givengroup.8.2 Sample SizeUse at least five test specimens to deter-mine the original physical properties of each sample. Also usefive or
43、more specimens of the same material for each exposureperiod of the test. But for purposes of statistical analysesdescribed in a later section, the number of specimens in thecontrol group and in each aged group should be the same. Theuser may increase the number of specimens in each group inresponse
44、to the size of the property change to be detected, thedegree of confidence desired, and the test result variability.This subject is further considered in Annex A1.9. Test Specimens9.1 Lap-shear test specimens must be made from the sameadherends and adhesive materials that are actually used inservice
45、. A tension lap-shear specimen made like the ones inFig. 2 and Fig. 3 is recommended. Methods for preparingwood-to-wood specimens are similar to those described in TestMethod D 2339 with modifications to accommodate masticconsistency adhesives.9.2 Wood-to-Wood Test Panel Preparation:9.2.1 Cut the ve
46、neer into suitable sizes and assemble it inpairs with the grain direction of the two sheets parallel to eachother. Fig. 4 shows a size that has been found convenient, andin this case the grain is parallel to the shorter dimension. Makesure the veneer is within 6 1 % of the moisture contentrecommende
47、d by the manufacturer of the adhesive. When themanufacturer does not give a recommendation, use a moisturecontent of 10 to 12 % based on ovendry weight in accordancewith Sections 122 to 125 of Test Methods D 143.9.2.2 If the specimens fail predominantly at the saw kerfs,prepare and test a new set of
48、 specimens with thicker veneers orsmaller distances between the saw kerfs such as 12.7 mm (0.5in.), as in Fig. 4.FIG. 1 Grips and JawsMetric EquivalentsDimen-sionToler-anceDimen-sionToler-ancemm in.A 82.6 60.25 3.25 60.010B 25.4 60.25 1.00 60.010C 3.17 60.10 0.125 60.004FIG. 2 Wood-to-Wood Tension S
49、hear Test SpecimenD 3632 98 (2004)39.2.3 Follow the directions of the adhesive manufacturerwhen applying the adhesive, but use a notched trowel to spreadadhesives of mastic consistency. Use a trowel with notchesshaped like equilateral triangles 3.2 mm (18 in.) on a side, andspaced 3.2 mm (18 in.) apart. During troweling, hold the trowelat approximately a 45-deg angle. Apply enough adhesive to fillthe notches of the trowel as it passes the length of the 305-mm(12-in.) veneer panel. After the open time prescribed by theadhesive manufacturer has elapsed, assemble t
