1、BRITISH STANDARD Plastics (polyester resins) and paints and varnishes (binders) Determination of partial acid value and total acid value The European Standard EN IS0 21 14:2000 has the status of a British Standard ICs 83.080.10 BS EN IS0 21 14:2000 Method 432B:2000 BS 2782-4: Incorporating Corrigend
2、um No. I Wk present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on th
3、is committee can be obtained on request to its secretary. Cr oss-r e fer enc e s Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standard
4、s which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard d
5、oes not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. 3 April 2002 Incorporating Annex ZA Summary of pages This doc
6、ument comprises a front cover, an inside front cover, the EN IS0 title page, the EN IS0 foreword page, the IS0 title page, pages ii toiv, pages 1 to 10, the Annex ZA page and a back cover. The BSI copyright date displayed in this document indicates when the This British Standard, having been prepare
7、d under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 November 2000 document was last issued. O BSI 3 April 2002 ISBN O 580 36545 X EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 2
8、114 August 2000 ICs 83.080.10 Supersedes EN IS0 2114:1996 English version Plastics (polyester resins) and paints and varnishes (binders) - Determination of partial acid value and total acid value (IS0 21 14:2000) Plastiques (rsines de polyesters) et peintures et vernis (liants) - Dtermination de lin
9、dice dacide partiel et de lindice dacide total (IS0 21 14:2000) Kunststoffe (Polyester) und Beschichtungsstoffe (Bindemittel) - Bestimmung der partiellen Surezahl und der Gesamtsurezahl (IS0 21 14:2000) This European Standard was approved by CEN on 1 August 2000. CEN members are bound to comply with
10、 the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat
11、 or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official ve
12、rsions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES
13、KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Central Secretariat: rue de Stassart, 36 B-1050 Brussels O 2000 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN IS0 21 14:2000 E EN IS0 2114:2000 I CORRECTED 2002-03-13 I Foreword T
14、his document (IS0 21 14:2000) has been prepared by Technical Committee ISO/TC 61 “Plastics“ in collaboration with Technical Committee CEN/TC 249 “Plastics“, the secretariat of which is held by IBN. This European Standard shall be given the status of a national standard, either by publication of an i
15、dentical text or by endorsement, at the latest by February 2001, and conflicting national standards shall be withdrawn at the latest by February 2001. This document supersedes EN IS0 21 14:1996. According to the CENKENELEC Internal Regulations, the national standards organizations of the following c
16、ountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International
17、 Standard IS0 21 14:2000 has been approved by CEN as a European Standard without any modifications. NOTE Normative references to International Standards are listed in annex ZA (normative). INTERNATIONAL STANDARD EN IS0 2114:2000 IS0 2114 Third edition 2000-08-01 Plastics (polyester resins) and paint
18、s and varnishes (binders) - Determination of partial acid value and total acid value Plasfiques (rsines de polyesfers) ef peinfures ef vernis (liants) - Dferminafion de lindice dacide partiel ef de lindice dacide fofa1 Reference number IS0 21 14:2000(E) EN IS0 2114:2000 II EN IS0 2114:2000 Contents
19、Page Foreword . iv 1 Scope 1 2 Normative references 1 3 Terms and definitions . 1 4 Principle 2 5 Reagents . 2 6 Apparatus . 3 7 Procedure . 4 8 Calculation and expression of results . 6 9 Precision . 7 10 Test report 8 Annex A (informative) Checking the concentration of the standard potassium hydro
20、xide solution . 9 . 111 EN IS0 2114:2000 Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member b
21、ody interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electro
22、technical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISOAEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Pu
23、blication as an 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 International Standard may be the subject of patent rights. IS0 shall not be held responsible for identifying any or
24、all such patent rights. International Standard IS0 21 14 was prepared by Technical Committee ISO/TC 61, Plasfics, Subcommittee SC 12, Thermoseffing maferials. This third edition cancels and replaces the second edition (IS0 2114:1996) as well as IS0 3682:1996, which have been technically revised. iv
25、EN IS0 2114:2000 Plastics (polyester resins) and paints and varnishes (binders) - Determination of partial acid value and total acid value 1 Scope This International Standard specifies methods of determining the partial acid value (method A) and the total acid value (method B) of polyester resins an
26、d binders for paints and varnishes. It is not applicable to phenolic resins. It is intended to provide quality-control data for the acceptance or rejection of such products in accordance with the terms of a specification, as well as to be used in research and development to monitor the completion of
27、 the polycondensation reaction. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not a
28、pply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members o
29、f IS0 and IEC maintain registers of currently valid International Standards. IS0 385-1 :I 984, Laborafory glassware - Bureffes - Par 1: General requiremenfs. IS0 3251 :I 993, Painfs and varnishes - Deferminafion of non-volafile maffer of painfs, varnishes and binders for painfs and varnishes. IS0 36
30、96:1987, Wafer for analyfical laborafory use - Specificafion and fesf mefhods. IS0 6353-2:1983, Reagenfs for chemical analysis - Par 2: Specificafions - Firsf series. 3 Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 3.1 acid value th
31、e number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of resin under the test conditions 3.2 partial acid value acid value corresponding to the neutralization of all the carboxyl-terminated groups and free acids plus half the free anhydrides in a resin 3.3 total acid value a
32、cid value corresponding to the neutralization of all the carboxyl-terminated groups and free acids plus all the free anhydrides in a resin 1 EN IS0 2114:2000 4 Principle 4.1 General The free acids/anhydrides contained in a test portion are titrated with potassium hydroxide solution, either potentiom
33、etrically or in the presence of a colour indicator. 4.2 Method A A weighed quantity of resin is dissolved in a solvent mixture. The solution is titrated potentiometrically (see note 1) with a standard volumetric solution of potassium hydroxide in ethanol, giving the following reaction: O O0 / II II
34、4 C R O + KOH + CzHgOH-CzHgOCRCOK+ HzO / C + O The amount, in milligrams, of potassium hydroxide used to neutralize 1 g of resin is then calculated. Method A is recommended for binders for paints and varnishes (as generally only small amounts of free anhydrides are present) but is also suitable for
35、unsaturated-polyester resins. 4.3 Method B A weighed quantity of resin is dissolved in a solvent mixture including water. The free anhydrides are allowed to hydrolyse for 20 min before titrating potentiometrically (see note 1) with a standard volumetric solution of potassium hydroxide in ethanol, gi
36、ving the following reaction: O O0 / II II 4 C R O + 2KOH - KOCRCOK + H2 O / C + O The amount, in milligrams, of potassium hydroxide used to neutralize 1 g of resin is then calculated. Method B is useful for unsaturated-polyester resins in which there are significant amounts of free anhydrides. NOTE
37、1 The use of a colour indicator for the titration is an optional alternative in both methods. NOTE 2 When titrating pure maleic polyester resins, it is better to use a methanolic solution of potassium hydroxide. 5 Reagents During the analysis, use only reagents of recognized analytical grade in acco
38、rdance with IS0 6353-2 and water of at least grade 3 as defined in IS0 3696. 5.1 volume. Solvent for method A solvent mixture containing 2 parts of toluene (5.7) and 1 part of ethanol (5.5) by Neutralize the solvent mixture with potassium hydroxide solution (5.3) prior to use, using phenolphthalein
39、as indicator if the determination is to be carried out by potentiometric titration (see 7.2.2) or, if the determination is to be carried out using an indicator (see 7.2.3), using the same indicator as will be used for the determination. 2 EN IS0 2114:2000 5.2 (5.9) and 50 ml of water. Solvent for me
40、thod B: solvent mixture containing 400 ml of pyridine (5.8), 750 ml of methyl ethyl ketone 5.3 carbonates. Potassium hydroxide, 0,l mol/l standard volumetric solution in ethanol (5.5) or in methanol (5.6), free from Check the concentration of this solution on the day of use (see annex A). If more th
41、an 25 ml of titrant will be required with a 0,l mol/l solution, use a 0,5 mol/l solution to avoid the additional errors involved in refilling the burette (6.3). 5.4 Acetone, containing less than 0,3 % by mass of water. 5.5 Ethanol, anhydrous, containing less than 0,2 % by mass of water. 5.6 Methanol
42、, anhydrous, containing 99,8 % by mass. 5.7 Toluene, anhydrous, containing less than 0,005 % by mass of water. 5.8 Pyridine, containing less than 0,05 % by mass of water. WARNING - Pyridine is toxic and flammable. Take proper precautions when handling this reagent. Avoid contact with the skin or eye
43、s. Use only in a well ventilated area in order to avoid breathing in the vapour. 5.9 Methyl ethyl ketone, containing less than 0,Ol % by mass of water. 5.10 Indicators (for optional alternative): 5.10.1 Bromothymol blue, 0,l % solution in ethanol (5.5). 5.10.2 Phenolphthalein, 1 % solution in ethano
44、l (5.5). 6 Apparatus Ordinary laboratory apparatus and glassware, plus the following: 6.1 6.2 6.3 6.4 Magnetic stirrer. Conical flasks, of capacities 100 ml and 250 ml, with a wide neck. Conical flask, of capacity 250 ml, with a narrow neck and fitted with a ground-glass stopper. Burette, of capacit
45、y 25 ml (graduated in 0,05 ml divisions), complying with the requirements of IS0 385-1. 6.5 6.6 Pipettes, of capacity 25 ml and 50 ml. Automatic pipettes, of capacity 25 ml, 50 ml and 60 ml. 6.7 Analytical balance, accurate to 1 mg. 6.8 electrode system and a titration stand. Potentiometric-titratio
46、n apparatus, comprising a suitable potentiometer fitted with a glass reference 3 EN IS0 2114:2000 I mg KOH/g 7 Procedure 7.1 Test portion By reference to Table 1, select the appropriate mass of test portion to be taken. Table 1 - Mass of test portion portion 9 I Expected acid value I Approximate mas
47、s of test I 10 to 25 25 to 50 4 2 o to 5 3 16 5to 10 8 7.2 Method A 7.2.1 Number of determinations Make two determinations. 7.2.2 Potentiometric-titration procedure Weigh each test portion into a 250 ml wide-neck conical flask (see 6.1) to the nearest 0,001 g (mass ml). Add 50 ml of solvent mixture
48、(5.1) using a pipette (6.5). Mix until the resin is completely dissolved. If solubility is incomplete after 5 min, prepare another test portion, but dissolve it in 50 ml of solvent mixture (5.1) and 25 ml of acetone (5.4). Place the conical flask on the titration stand (see 6.8) and adjust its posit
49、ion so that the electrode is well immersed. Titrate potentiometrically with potassium hydroxide solution (5.3) using a burette (6.3). Record the volume (VI), in millilitres, of KOH solution used to reach the end point (the point of inflection of the titration curve). Carry out a blank determination in the same way, using 50 ml of solvent mixture and, if needed, 25 ml of acetone. Record the volume (V2), in millilitres, of KOH solution used. If the neutralization of the solvent mixture has been carried out correctly, the result of the blank determination will be zero
