1、Designation: E 1090 96 (Reapproved 2002)Standard Test Method forDicumyl Peroxide and Dicumyl Peroxide DecompositionProducts in Resins1This standard is issued under the fixed designation E 1090; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 test method is applicable to the determination ofdicumyl peroxide2and the decomposition p
3、roducts dimethyl-benzyl alcohol and acetophenone in cured and uncured poly-ethylene (PE) and ethylene vinyl acetate (EVA) resins. Theseuncured polymers normally contain from 1 to 2 % dicumylperoxide, whereas the residual peroxide level in the curedpolymers is usually less than 0.1 %.1.2 This standar
4、d 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. Specific precau-tionary statem
5、ents are given in Section 7.1.3 Review the current Material Safety Data Sheets (MSDS)for detailed information concerning toxicity, first aid proce-dures, and safety precautions.2. Referenced Documents2.1 ASTM Standards:3D 1193 Specification for Reagent WaterE 180 Practice for Determining the Precisi
6、on of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 300 Practice for Sampling Industrial ChemicalsE 682 Practice for Liquid Chromatography Terms and Re-lationshipsE 685 Practice for Testing Fixed-Wavelength PhotometricDetectors Used in Liquid ChromatographyE 755 Test M
7、ethod for Dicumyl Peroxide, Assay (LiquidChromatography)3. Summary of Test Method3.1 Dicumyl peroxide and dimethylbenzyl alcohol are ex-tracted from a cryogenically ground sample with methylenechloride. The extract is concentrated, redissolved in methanol,and analyzed by high performance liquid chro
8、matography(HPLC). Acetophenone is extracted from a separate samplewith methanol and analyzed directly by HPLC. The analysesare performed on a reversed phase octadecylsilane (ODS)column using acetonitrile/water as the mobile phase and anultraviolet detector at 254 nm. The concentration of eachcompone
9、nt is determined by the internal standard technique,using peak height ratios of the sample and standard chromato-grams.4. Significance and Use4.1 Knowledge of the peroxide content of uncured PE andEVA samples is required to regulate the degree of crosslinkingin the cured product. As end use applicat
10、ions of the curedproduct can be affected by residual amounts of the peroxide orits decomposition productsdimethylbenzyl alcohol andacetophenoneknowledge of these levels is also important.This test method provides a procedure for determining theconcentration of these compounds. A method for the HPLCa
11、ssay of dicumyl peroxide is described in Test Method E 755.5. Apparatus5.1 Liquid Chromatograph, equipped with a 254-nm UVdetector, injection valve, and an isocratic-solvent deliverysystem capable of operating to a gage pressure of 3000 psi. The1This test method is under the jurisdiction of ASTM Com
12、mittee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.01 on General Standards.Current edition approved Oct. 10, 2002. Published February 2003. Originallyapproved in 1986. Last previous edition approved in 1996 as E 1090 96.2Dicumyl peroxide; peroxide, bi
13、s(1-methyl-1-phenylethyl) C18H22O2; CASRegistry No. 80-43-3.3For 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.1
14、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.detector should be equipped with an attenuator switch tochange the sensitivity range as required. (See Practices E 682and E 685.)5.2 Recorder, 0 to 1 mv range,1sorless full-scaledeflecti
15、on, with a chart speed of 0.1 in./min or other convenientspeed that will produce a satisfactory chromatogram. As analternative, an electronic data system can be used.5.3 Chromatographic Column, reversed phase C-18, from250 to 300-mm by 3.9-mm inside diameter, containing octa-decylsilane chemically b
16、onded to microparticulate silica.4NOTE 1Commercial HPLC columns may vary in physical dimen-sions, degree of substrate loading, and size and type of support material.For these reasons, some modification in the operating parameters may berequired to achieve optimum separation.5.4 Guard Column, reverse
17、d phase C-18, containing octa-decylsilane chemically bonded to microparticulate silica.5.5 Filter Funnel, Buchner, 60-mL capacity, with mediumporosity glass frit.5.6 Vials, screw cap, 4-dram and 1-dram capacities, withPTFE-lined caps.5.7 Freezer Mill, for pulverizing samples at liquid nitrogentemper
18、ature.55.8 Bottles, screw cap, wide-mouth, 2-oz capacity, withPTFE-lined caps.5.9 Sample Filter, consisting of a syringe and 0.45-m filterassembly to remove microparticulate matter from the preparedsample solution.65.10 Tube, borosilicate glass, approximately 8-in. long by1-in. diameter with tapered
19、 end, for warming cryogenicallyground resin samples to ambient temperature (see Fig. 1).5.11 Solvent Evaporation AssemblySee Fig. 2.5.12 Silica Gel Purification Column.76. Reagents6.1 Methanol, chromatographic grade, distilled in glass.6.2 Acetonitrile, chromatographic grade, distilled in glass.6.3
20、Water, prepare Type II reagent water in accordance withSpecification D 1193, or distill deionized water. Filter througha 0.45-m filter8and store in a glass container.6.4 Acetonitrile:Water, 70:30Mix 7 volumes of acetoni-trile with 3 volumes of water.6.5 Acetonitrile:Water, 30:70Mix 3 volumes of acet
21、oni-trile with 7 volumes of water.6.6 Acetonitrile:Water, 95:5Mix 9.5 volumes of acetoni-trile with 0.5 volumes of water.6.7 Methylene Chloride, chromatographic grade, distilled inglass.6.8 Dibutyl Phthalate, purified.96.9 Dibutyl Phthalate Internal Standard (approximately 7.0mg/mL)Weigh 7.0 6 0.1 g
22、 of dibutyl phthalate to the nearest0.1 mg. Dissolve in methanol and quantitatively transfer to a1-L volumetric flask. Dilute to volume with methanol and mixthoroughly. Calculate the exact concentration of dibutyl phtha-late.6.9.1 Long-term storage of a methanolic solution of dibutylphthalate should
23、 be avoided. Dibutyl phthalate in the presenceof traces of acidic or basic impurities may transesterify. Iftransesterification occurs, the dibutyl phthalate peak willslowly decrease, and the appearance of the methylbutyl phtha-late peak (k1value about 3.8) will be noted.6.10 Dibutyl Phthalate Intern
24、al Standard (approximately0.7 mg/mL)Pipet 100 mL of dibutyl phthalate standard (6.9,approximately 7 mg/mL) into a 1-L volumetric flask. Dilute tovolume with methanol and mix thoroughly. Calculate the exactconcentration of dibutyl phthalate.6.11 Benzyl Alcohol, purified.106.12 Benzyl Alcohol Internal
25、 Standard (approximately 15.0mg/mL)Weigh 15.0 6 0.1 g of benzyl alcohol to the nearest0.1 mg. Dissolve in methanol and quantitatively transfer to a1-L volumetric flask. Dilute to volume with methanol and mixthoroughly. Calculate the exact concentration of benzyl alco-hol.6.13 Benzyl Alcohol Internal
26、 Standard (approximately 1.5mg/mL)Pipet 100 mL of benzyl alcohol standard (6.12,approximately 15 mg/mL) into a 1-Lvolumetric flask. Dilute tovolume with methanol and mix thoroughly. Calculate the exactconcentration of benzyl alcohol.6.14 Dicumyl Peroxide, RecrystallizedTransfer 25.0 g ofcommercial r
27、efined dicumyl peroxide into a 100-mL Erlenm-eyer flask. Add 8.0 mL of methanol and gently warm thesolution in a water bath while swirling, to effect completesolution. Cool to 0C in an ice bath. Transfer the contents to amedium-porosity sintered glass crucible and vacuum filter.Allow air to pass thr
28、ough the filter for 10 to 15 min, to dry theperoxide. Repeat the crystallization twice using approximately1 mL of methanol for every3gofperoxide. Place therecrystallized dicumyl peroxide in a tightly capped bottle andstore in the refrigerator. Cautionsee Section 7.4Satisfactory results were obtained
29、 using Waters -Bondapak C-18 (Cat. No.27324) and Waters Radial PAK C-18 (Cat. No. 84720) columns in a round-robinevaluation of the test method. Equivalent results should be obtained with othercommercial C-18 reversed phase columns.5A Spex Freezer/Mill, Catalog No. 6700, has been found to be satisfac
30、tory forthis purpose. This mill is available from Spex Industries, Inc., Metuchen, NJ.6WatersAssociations Sample Clarification Kit, Catalog No. 26870, was found tobe satisfactory for this purpose.7SEP-PAK silica gel cartridges, Waters No. 51-900, have been found to besuitable for this purpose.8A0.45
31、-m Millipore type HA filter was found to be satisfactory for thispurpose.9Dibutyl phthalate, Aldrich Chemical Co. No. 15243-9, was found to besatisfactory for this use.10Benzyl alcohol, Aldrich Chemical Co. No. B1620-8, was found to besatisfactory for this use.FIG. 1 Tube for Warming Cryogenically G
32、round Resin Samples toAmbient TemperatureE 1090 96 (2002)26.15 Acetophenone, purified.116.16 a,a-Dimethylbenzyl Alcohol (DMBA)Dissolve 0.2 gof a,a-dimethylbenzyl alcohol12in 2 mL of 98:2n-hexane:chloroform. Transfer the solution into a 5-mL syringeand carefully pass the solution through a SEP-PAK si
33、lica gelcartridge. Discard the eluate. Wash the column with anadditional 2 mLof 98:2 n-hexane:chloroform and again discardthe eluate. Then, elute the DMBA with 5 mL of chloroform,collecting the eluate in a 50-mLfiltering flask. Stopper the flaskand attach the side arm to a water aspirator. Immerse t
34、he flaskin a water bath maintained at 35 to 40C until the chloroformhas completely volatilized. Store the purified DMBA in asealed vial.7. Precautions7.1 Organic peroxides are strong oxidizing agents andpresent potential fire and explosion hazards. Reactivity varieswidely and some compounds may expl
35、ode when shocked.While dicumyl peroxide is one of the more stable peroxides,contact with reducing agents and sources of heat, sparks, oropen flame must be avoided. Organic peroxides in general areirritating to the skin, eyes, and mucous membranes. Avoidbodily contact and handle only in a well-ventil
36、ated area.7.2 Small quantities of solid or molten dicumyl peroxidecan be safely handled at temperatures up to 55C. Dicumylperoxide should not be heated above 55C as the rate ofperoxide decomposition rapidly increases with increasing tem-peratures above this point.7.3 Only a water bath that has been
37、preheated to the desiredtemperature and removed from the heat source should be usedfor warming vessels containing dicumyl peroxide. Electricallyheated water baths should not be used as they may causelocalized hot spots. Other sources of heat considered unsafe forwarming containers of dicumyl peroxid
38、e include ovens, hotplates, and direct steam.8. Sample Preparation8.1 Obtain at least3gofarepresentative sample and reducethe particle size, if required, to approximately18 in. or lessusing stainless-steel shears. (See Practice E 300.)8.2 Charge the stainless-steel sample vial with approxi-mately 1.
39、5 g of sample, add the stainless-steel impactor rod,and cap the vial with the stainless-steel cover head.8.3 Carefully position the vial in the freezer/mill which hasbeen precooled and filled with liquid nitrogen to the properlevel.11Acetophenone, 99 %, Aldrich Chemical Co. No. A1,070-1, was found t
40、o besatisfactory for this use.12a,a-Dimethylbenzyl alcohol, 99 %, Fluka Chemical Corp. No. 78940, wasfound to be satisfactory for this use.FIG. 2 Solvent Evaporation Assembly for Preventing Accumulation and Loss of Volatile CompoundsE 1090 96 (2002)38.4 Cool for 4 to 5 min, then activate the impacto
41、r and allowto pulverize for 3 to 4 min at optimum impactor rate. Consultmanufacturers instructions for detailed operating procedure.58.5 Remove the sample vial and immediately place in aborosilicate tube through which a flow of dry air or nitrogen ismaintained. See Fig. 1. Allow to warm to ambient t
42、emperatureunder the dry air or nitrogen flow in order to excludeatmospheric moisture.8.6 Remove the pulverized sample and store in a clean,capped vial.8.7 Repeat 8.2-8.5 and combine with the pulverized productobtained in 8.6. Reserve for extraction and HPLC analysis.9. Procedure9.1 Preparation of Sa
43、mple for Determination of DicumylPeroxide and Dimethylbenzyl Alcohol:9.1.1 Weigh a 2.0 6 0.1-g sample of cryogenically groundresin to the nearest 0.1 mg and transfer to a 2-oz bottleequipped with a PTFE-lined screw cap.9.1.2 Add approximately 30 mL of methylene chloride, cap,and shake. Allow to stan
44、d at ambient temperature for 18 h withoccasional shaking to complete the extraction.9.1.3 Filter through a medium porosity sintered-glass filtercollecting the filtrate in a 125-mL filter flask. Rinse the resinwith several small portions of methylene chloride, collectingthe washings in the flask.9.1.
45、4 Quantitatively transfer the filtrate to a 50-mL beakerusing a minimum amount of methylene chloride to aid in thetransfer.9.1.5 Place the beaker on the solvent-evaporation assemblyand direct a gentle stream of N2or dry air against the surfaceof the extract. The surface temperature of the aluminum p
46、lateshould be maintained from 70 to 80C and a14 to12-in. spacemaintained between the beaker and the aluminum foil as shownin Fig. 2.9.1.6 Evaporate the filtrate until the volume is reduced from1 to 2 mL. Do not evaporate to dryness.9.1.7 Quantitatively transfer the solution to a 1-dram PTFE-lined sc
47、rew cap vial using a minimum amount of methylenechloride to aid in the transfer.9.1.8 Place the vial on the evaporation assembly and con-tinue the evaporation until the solvent has almost completelyevaporated.9.1.9 Pipet 0.50 mL of dibutyl phthalate internal standard(0.7 mg/mL) and 0.50 mL of benzyl
48、 alcohol internal standard(1.5 mg/mL) into the vial, then cap and mix thoroughly.9.1.10 Transfer the solution into the syringe of the sampleclarification kit6and filter the solution through a 0.45-m filtercollecting the clear filtrate in a clean 1-dram vial fitted with aPTFE-lined screw cap. Cap and
49、 reserve for analysis.9.2 Preparation of Sample for Determination of Acetophe-none:9.2.1 Weigh a 2.0 6 0.1-g sample of cryogenically groundresin to the nearest 0.1 mg and transfer to a 25-mL volumetricflask.9.2.2 Pipet 10.00 mL of benzyl alcohol internal standard(1.5 mg/mL) into the flask and dilute to volume with methanol.Stopper and mix. Allow to stand for 18 h at ambient tempera-ture with occasional shaking to complete the extraction.9.2.3 Transfer a portion of the supernatant extract into thesyringe of the sample clarification kit6and filter through
