ISO INTERNATIONAL STANDARD 62 Third edition 2008-02-15 PlasticsDeterminationofwater absorption Plastiques-Determination de Iabsorption d'eau Reference number ISO 62:2008(E) TSO @ISO2008 ISO 62:2008(E) Contents Page Foreword iv Introduction 1 Scope 2 Normative references 3 Principle 4 Apparatus 5 Testspecimens 5.1 General 5.2 Square-shaped test specimens for homogeneous plastics 5.3 Test specimens of reinforced plastics affected by anisotropic diffusion effects 5.4 5.5 Rod..shaped test specimens ..... 5.6 Specimenscutfromfinishedproducts,extrusioncompounds,sheetsorlaminates... 6 Test conditions and procedures ... 6.1 General... 6.2 6.3 Method1:Determinationofamountofwaterabsorbedafter immersion inwaterat23°c 6.4 Method 2: Determination of amount of water absorbed after immersion in boiling water.... 5 6.5 Method 3: Determination of water-soluble matter lost during immersion.... 6.6 Method4:Determinationofamountofwaterabsorbedafterexposureto50%relative humidity.... 6 7 Expression of results.... 6 7.1 Percentagebymass ofwaterabsorbed... 6 7.2 Determination of the water content at saturation and the water diffusion coefficient using Fick'slaws.. 8 Precision 8 9 Test report. .9 AnnexA(informative)CorrelationbetweenwaterabsorptionbytestspecimensandFick's diffusion laws... 10 Annex B (informative)Precision statement... Bibliography. 15 @ IS0 2008 - All rights reserved ili ISO 62:2008(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies technical committees. Each member body interested in a subject for which a technical committee has been non-governmental, in liaison with iso, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/lECDirectives,Part2 International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. isO shall not be held responsible for identifying any or all such patent rights. and environmental resistance beenadded. iv @ ISO 2008-All rights reserved ISO 62:2008(E) Introduction Plastics exposed to waterare subject to several different effects: a) dimensional changes (e.g. swelling) caused by absorption of water; b) extraction ofwater-soluble components; C) changes inotherproperties. material responses. The equilibrium moisture content can be used to compare the amount of water absorbed by different types of plastics when they are exposed to moisture. Moisture content determined under non- equilibrium conditions can be used to compare different batches of the same material and to determine the diffusion constant of the material when determined under carefully controlled non-equilibrium conditions of exposure to moisture and when using plastic specimens of defined dimensions. INTERNATIONALSTANDARD ISO62:2008(E) Plastics Determination of water absorption 1 Scope 1.1 This International Standard describes a procedure for determining the moisture absorption properties in the "through-the-thickness" direction of flat or curved-form solid plastics. This International Standard also describes procedures for determining the amount of water absorbed by plastic specimens of defined "through-the-thickness" moisture diffusion coefficient can be determined for single-phase materialby assumingFickiandiffusionbehaviourwithconstantmoistureabsorptionpropertiesthroughthethicknessof the test specimen. materials and for reinforced polymer-matrix compositestestedbelowtheirglasstransitiontemperature.However,sometwo-phasematricessuchas hardened epoxies may require a multi-phase absorption model which is not covered by this International Standard. 1.2Ideally, the best comparison of the water absorption properties and/or diffusion coefficients of materials