【英文标准名称】:StandardClassificationforRubberCompoundingMaterialsx2014;Sulfur
【原文标准名称】:橡胶配料的标准分类:硫
【标准号】:ASTMD4528-1988(2007)
【标准状态】:现行
【国别】:美国
【发布日期】:1988
【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】:D11.20
【标准类型】:(Classification)
【标准水平】:()
【中文主题词】:
【英文主题词】:insolublesulfur;rhombicsulfur;sulfur;Chemicalanalysis--rubberchemicals/materials;Classification(standards)--rubber;Insolublemattercontent--rubber;Rhombicsulfur;Rubbercompoundingmaterials;Sulfur--rubber
【摘要】:Sulfurisoneoftheprincipalrubbervulcanizingagents.Itisacriticaladditive.Whenchemicallycombinedwithrubber,sulfurdevelopsbasicperformancepropertiesinthevulcanizedcompoundsuchas:tensilestrength,elongation,modulus,andhardness.Insoftorelasticrubbercompounds,sulfurisanessentialbutminoradditive.Insemi-hardrubberandebonite,sulfurbecomesamajorcompoundingmaterialwhileretainingitsroleasavulcanizingagent.Themoststablemolecularformofsulfuratambientconditionsisaringstructurecontainingeightsulfuratoms.Dependingonconditionsthesemoleculesorientintooneoftwocrystallinestructures.Atroomtemperaturethecrystalsarerhombicandabove95x00B0;Ctheyrearrangetomonoclinic.Lessthan1.5%ofeithercrystallinestructureofsulfurissolubleinanyrubberatroomtemperature.Thesecondcommonmolecularformofsulfurispolymericsulfur,madeupofunbranchedchainsofsulfuratoms.Itiscommonlyreferredtointherubberindustryasinsolublesulfur.Whenthismaterialiscreatedbyrapidheatingtoabove160x00B0;Candquenchingtoroomtemperature,thesulfurisamorphous.Ifformedunderotherconditions,thepolymerchainsmaydevelopregionsofpseudocrystallinity.Insolublesulfurisanimportantformofsulfurusedonlyintherubberindustry.Itisnotsolubleinanytypeofrubberhydrocarbon.Whenitismixedinrubber,itdispersesbutremainsundissolvedintherubber.Theuseofinsolublesulfurpreventsthedevelopmentofasupersaturatedsolutionofsulfurinrubberthatoccurswhenrhombicsulfurisused.Nosulfurbloomwilldeveloponthesurfaceofuncuredrubberpieceswhentherubbercoolsaftermixingorprocessing;therefore,buildingtackispreserved.Atcuringtemperatures,insolublesulfurrapidlytransformstoasolublespecies,dissolvesintherubber,andentersintothevulcanizationprocess.1.1Thisclassificationcoversthevarietyofsulfurgradesusedintherubberindustry.Typicalchemicalandphysicalpropertiesforsulfurareshown.Sulfurisprincipallyusedinunsaturatedrubbersasavulcanizingagent.
【中国标准分类号】:G34
【国际标准分类号】:83_040_20
【页数】:3P.;A4
【正文语种】:英语


【英文标准名称】:Airfilterunits
【原文标准名称】:空气过滤器组件
【标准号】:UL900-1994
【标准状态】:作废
【国别】:美国
【发布日期】:1994-11-28
【实施或试行日期】:
【发布单位】:美国保险商实验所(UL)
【起草单位】:UL
【标准类型】:()
【标准水平】:()
【中文主题词】:试验;燃烧特性;可洗性;飞火;空气过滤器;尘埃过滤器;气载粉尘;易燃性;可处置的;燃烧的影响
【英文主题词】:flyingbrands;flammability;washability;airbornedust;influenceofflame;dustfilters;airfilters;testing;disposables;burningbehaviours
【摘要】:
【中国标准分类号】:J77
【国际标准分类号】:23_120
【页数】:11P;A4
【正文语种】:英语