标准资料网-标准资料免费资源平台

【英文标准名称】:Cellularplasticsandrubbers-Determinationofapparentdensity
【原文标准名称】:泡沫塑料和橡胶.表观密度的测定
【标准号】:ISO845-2006
【标准状态】:现行
【国别】:国际
【发布日期】:2006-12
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC61
【标准类型】:()
【标准水平】:()
【中文主题词】:表观密度;体密度;多孔材料;定义;密度测量;泡沫橡胶;材料试验;方法;塑料;刚性;橡胶;试样;试验;处理;硫化橡胶
【英文主题词】:Apparentdensity;Bulkdensity;Cellularmaterials;Definitions;Densitymeasurement;Foamedrubber;Materialstesting;Methods;Plastics;Rigid;Rubber;Testspecimens;Testing;Treatment;Vulcanizedrubber
【摘要】:ThisInternationalStandardspecifiesamethodfordeterminingtheapparentoveralldensityandtheapparentcoredensityofcellularplasticsandrubbers.Ifthematerialtobetestedincludesskinsformedduringamoulding/extrusion,theapparentoveralldensityortheapparentcoredensity,orboth,canbedetermined.Ifthematerialdoesnothaveskinsformedduringmoulding,theterm"overalldensity"isnotapplicable.Forshapedmaterials,adifferentmethodsuchasbuoyancymethodmaybeused.
【中国标准分类号】:G31
【国际标准分类号】:83_100
【页数】:4P;A4
【正文语种】:英语


【英文标准名称】:StandardTestMethodforDeterminationofWeight-AverageMolecularWeightofPolymersByLightScattering
【原文标准名称】:用低扩散法测定聚合物分子量和平均分子量的标准试验方法
【标准号】:ASTMD4001-1993(2006)
【标准状态】:现行
【国别】:
【发布日期】:1993
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D20.70
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:高聚物;塑料;测定;工艺;分子量
【英文主题词】:lightscattering;polymers;weight-averagemolecularweight
【摘要】:Theweight-averagemolecularweightisafundamentalstructureparameterofpolymers,whichisrelatedtomanyphysicalpropertiesofthebulkmaterial,suchasitsrheologicalbehavior.Inaddition,knowledgeoftheweight-averagemolecularweight,togetherwithknowledgeofthenumber-averagemolecularweightfromosmometry,providesausefulmeasureofthebreadthofthemolecular-weightdistribution.Otherimportantusesofinformationontheweight-averagemolecularweightarecorrelationwithdilute-solutionormelt-viscositymeasurementsandcalibrationofmolecular-weightstandardsforuseinliquid-exclusion(gel-permeation)chromatography.Totheextentthatthelight-scatteringphotometerisappropriatelycalibrated,lightscatteringisanabsolutemethodandmaythereforebeappliedtononionichomopolymersthathavenotpreviouslybeensynthesizedorstudied.1.1Thistestmethoddescribesthetestproceduresfordeterminingtheweight-averagemolecularweightMwofpolymersbylightscattering.Itisapplicabletoallnonionichomopolymers(linearorbranched)thatdissolvecompletelywithoutreactionordegradationtoformstablesolutions.Copolymersandpolyelectrolytesarenotwithinitsscope.Theprocedurealsoallowsthedeterminationofthesecondvirialcoefficient,A2,whichisameasureofpolymer-solventinteractions,andtheroot-mean-squareradiusofgyration(s2)1/2,whichisameasureofthedimensionsofthepolymerchain.1.2Themolecular-weightrangeforlightscatteringis,tosomeextent,determinedbythesizeofthedissolvedpolymermoleculesandtherefractiveindicesofsolventandpolymer.Arangefrequentlystatedis10,000to10,000,000,butthismaybeextendedineitherdirectionwithsuitablesystemsandbytheuseofspecialtechniques.1.2.1Thelowerlimittomolecularweightresultsfromlowlevelsofexcesssolutionscatteringoverthatofthesolvent.Thegreaterthespecificrefractiveincrementdn/dc(differenceinrefractiveindicesofsolutionandsolventperunitconcentration),thegreaterthelevelofsolutionscatteringandthelowerthemolecularweightthatcanbedeterminedwithagivenprecision.1.2.2Theupperlimittomolecularweightresultsfromtheangulardependenceofthesolutionscattering,whichisdeterminedbythemolecularsize.Forsufficientlylargemolecules,measurementsmustbemadeatsmallscatteringangles,whichareultimatelyoutsidetherangeofthephotometerused.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.TherearenosimilarorequivalentISOstandards.
【中国标准分类号】:G31
【国际标准分类号】:83_080_01
【页数】:12P.;A4
【正文语种】: