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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 2028:1999 ICS 83.0
2、40.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Synthetic rubber latex Preparation of dry polymer Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared under the direction of
3、 the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15April 2000 BSI 04-2000 ISBN 0 580 34683 8 BS ISO 2028:1999 Amendments issued since publication Amd. No.DateComments National foreword This British Standard repro
4、duces verbatim ISO 2028:1999 and implements it as the UK national standard. It supersedes BS 6057-3.16:1990 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/50, Natural and synthetic rubbers, which has the responsibility to: aid enquirers to unders
5、tand the text; 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 t
6、his committee can be obtained on request to its secretary. Cross-references The British Standards 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, o
7、r by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does 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 im
8、munity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed C
9、opy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARD ISO 2028 Fourth edition 1999-12-15 Reference number ISO 2028:1999(E) Synthetic rubber latex Preparation of dry polymer Latex de caoutchouc synthtique Prparation du polymre sec Lice
10、nsed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2028:1999(E) ii? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2028:1999(E) ?iii Foreword ISO (the International Organization fo
11、r Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical com- mittees. Each member body interested in a subject for which a technical committee has been established has t
12、he right to be represented on that committee. International organizations, governmental and non-governmental, in liai- son with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Inter
13、national Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the me
14、mber 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. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 2028 was prepared by Technical C
15、ommittee ISO/TC 45,Rubber and rubber products, Subcommittee SC 3,Raw materials (including latex) for use in the rubber industry. This fourth edition cancels and replaces the third edition (ISO 2028:1989), which has been technically revised. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:3
16、8:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARD?ISO 2028:1999(E) ?1 Synthetic rubber latex Preparation of dry polymer WARNING Persons using this International Standard sh
17、ould be familiar with normal laboratory practice. This International Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national
18、regulatory conditions. 1Scope This International Standard specifies four methods for the isolation of dry polymer from synthetic polymer latices con- taining anionic surfactants, for the purpose of subsequent testing. Tests that may be performed include the determi- nation of the Mooney viscosity, t
19、he bound-styrene or acrylonitrile content in the polymer chain or the mill shrinkage. Because of the wide variety of surfactants and stabilizers that are used in the manufacture of synthetic rubber latices, no one method is suitable for all latices. The methods given in this International Standard a
20、re suitable for a wide variety of latices, but their applicability should be confirmed for individual types. Latices containing non-ionic stabiliz- ers, in particular, may be resistant to coagulation. These methods are not necessarily suitable, without modification, for latices containing polymers h
21、aving high tack. It should be noted that the dry polymer as isolated may contain residual organic acids or their aluminium salts which may affect the properties of the polymer. This should be taken into account when performing analytical tests. 2Normative references The following normative documents
22、 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 publica- tions do not apply. However, parties to agreements based on this International Standard are encourag
23、ed to investi- gate 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 of ISO and IEC maintain registers of currently valid International Standards. ISO 123
24、:1),Rubber latex Sampling. ISO 124:1997,Latex, rubber Determination of total solids content. 3Principle The latex is coagulated in the presence of an antioxidant, using different procedures depending on the type of latex. The resultant crumb is washed with water and dried in a ventilated oven at?to
25、constant mass. NOTEFreezing is also a suitable method for the isolation of some latices; sufficient details of the method are not available for inclusion in this edition of ISO 2028. 1)To be published. (Revision of ISO 123:1985) 70 C Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GM
26、T+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2028:1999(E) 2? 4Reagents During the preparation of the reagent solutions and the isolation of the polymer, use only distilled water or water of equivalent purity. 4.1Coagulant A: An aqueous solution of a polyamine polyelectrolyte, prepared by dissolving?
27、of polyamine polyelectrolyte in?of hot,?water and then diluting the resultant solution to?. NOTE 1Suitable polyamine polyelectrolytes include “Prodefloc CRC 300C” (CAS No. 42751-79-1) available from Industrie Chimiche Caffara SpA, Casella postale 327, 25100 Brescia, Italy, and “EPI DNA” available fr
28、om AcqueNYMCO SpA, 20032 Cormano MI, Via dei Giovi 6, Italy, Fax 66301278. NOTE 2Any residues of polyamine electrolyte left in the polymer following isolation are likely to interfere in the determination of bound acrylonitrile. 4.2Coagulant B: A solution of aluminium sulfate in dilute sulfuric acid.
29、 Prepare dilute sulfuric acid by slowly and cautiously adding?of concentrated sulfuric acid to?of water and cooling. Separately, prepare a solution of aluminium sulfate by adding?of?aluminium sulfate solution to?of water and straining through a piece of gauze. Add the diluted aluminium sulfate solut
30、ion to the diluted sulfuric acid and adjust the volume to?with water. 4.3Antioxidant, for example trinonyl phenyl phosphite (TNPP). NOTEThe antioxidant chosen should preferably be one known to be suitable for use with the polymer to be isolated. Prepare an aqueous emulsion of antioxidant containing?
31、of antioxidant in?of emulsion. 4.4Aluminium sulfate solution, prepared by dissolving?of aluminium sulfate in water and diluting the resultant solution to?. 4.5Ethanol, minimum purity?. 5Apparatus Standard laboratory equipment plus the following: 5.1Stainless-steel beaker,?capacity. 5.2Graduated cyli
32、nders,?,?and?capacity. 5.3Electric stirrer, with two propeller-type blades of approximately?diameter, mounted?apart at right angles to the shaft. 5.4Magnetic stirrer. 5.5Suitable device for injecting steam, fed from a low-pressure source. NOTESteam is the most efficient method of heating liquids rap
33、idly. 5.6Gauze filter, e.g. cheese cloth. 5.7Drying pan: An aluminium or enamel-lined pan with a suitable surface area (approximately?) on which to spread out the crumb for drying. It is desirable that the pan should be relatively light in weight. 5.8Ventilated oven, capable of being maintained at?.
34、 5.9Balance, capable of being read to?. 2,5 g 1 dm350 C 10 dm3 82 cm31 dm3 200 cm3500 g/dm3200 cm3 1,5 dm3 25 g 100 cm3 4 g 100 cm3 99 % 5 dm3 10 cm3500 cm31000 cm3 35 mm 50 mm 500 cm2 70 C 5 C 0,1 g Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (
35、c) BSI ISO 2028:1999(E) ?3 6Procedure 6.1General Use a test sample of the latex prepared by one of the methods described in ISO 123. If the solids content of the latex is not known, determine it in accordance with ISO 124. 6.2Styrene-butadiene (SBR) latices (of less than?solids content) 6.2.1If it i
36、s not known whether or not the latex contains an antioxidant, transfer a portion of the test sample contain- ing approximately?of dry polymer to a clean, dry beaker and add?of the antioxidant emulsion (4.3). Stir well. 6.2.2Transfer?of coagulant A (4.1) to a?stainless-steel beaker (5.1) and heat to
37、by injecting steam (see 5.5). Introduce the electric stirrer and stir at approximately (?) while adding, in a slow stream, a quantity of latex containing approximately?of dry polymer with antioxidant (see 6.2.1). Continue stirring for?to ensure uniform mixing, then slowly add?of coagulant B (4.2) dr
38、opwise. If complete precipitation is not achieved with the formation of fine crumbs and a clear serum, add a further?of coagulant B. 6.2.3Strain through a clean gauze (5.6) and wash the residue of precipitated rubber particles with water at for?. Allow the gauze to drain, then wrap it around the pre
39、cipitated rubber and transfer it to a beaker containing water at?. Allow to soak for a further?while holding the gauze under the water and squeezing gently with the fingers. Remove the gauze containing the crumbs from the water and squeeze to eliminate as much water as is practical. 6.2.4Transfer th
40、e damp polymer crumbs to a suitable pan (5.7) lined with a double layer of clean gauze and ensure that they are well spread out over the whole surface area. Dry in a ventilated oven (5.8) at?for?. Using a balance (5.9), weigh the container and dried crumbs. Record the mass to?. Return the container
41、to the oven for a further?and re-weigh. Continue to dry in the oven for?periods until the loss in mass between succes- sive weighings is less than?. 6.3Carboxylated (X-SBR and X-NBR) latices 6.3.1If it is not known whether or not the latex contains an antioxidant, transfer a portion of the test samp
42、le contain- ing approximately?of dry polymer to a clean, dry beaker and add?of the antioxidant emulsion (4.3). Stir well. 6.3.2Take a portion of latex containing approximately?of dry polymer with antioxidant (see 6.3.1) in a beaker and add?of water. Stir well. Proceed as described in 6.2.2, 6.2.3 an
43、d 6.2.4. 6.4Nitrile (NBR) latices 6.4.1If it is not known whether or not the latex contains an antioxidant, transfer a portion of the test sample contain- ing approximately?of dry polymer to a clean, dry beaker and add?of the antioxidant emulsion (4.3). Stir well. 6.4.2Transfer?of the diluted alumin
44、ium sulfate solution (4.4) to a?stainless-steel beaker (5.1) and raise the temperature to?by passing in steam (see 5.5). Remove the steam injector and introduce the electric stirrer (5.3). Stir at approximately?(?) while adding, in a slow stream, a portion of the latex contain- ing approximately?of
45、dry polymer together with antioxidant (see 6.4.1). Continue stirring for a further?, then proceed as described in 6.2.3 and 6.2.4. 55 % 100 g 10 cm3 2 dm350 cm35 dm3 65 C 5 C 105 rad/s 1 000 r/min 100 g 1 min 15 cm3 1 cm3 50 C 5 C 120 s15 s 40 C 5 C 120 s15 s 70 C 5 C 5 h 0,1 g 1 h 1 h 0,5 g 100 g 1
46、0 cm3 100 g 1 dm3 500 cm3 100 g 10 cm3 2 dm35 dm3 65 C 5 C 105 rad/s 1000 r/min 100 g 5 min Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 07:38:07 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2028:1999(E) 4? 6.5Concentrated latices (more than?solids content) 6.5.1If it is not known whethe
47、r or not the latex contains an antioxidant, transfer a?portion of the test sample to a clean, dry beaker and add?of the antioxidant emulsion (4.3). Stir until thoroughly mixed. 6.5.2Transfer?of ethanol (4.5) into a?stainless-steel beaker equipped with a magnetic stirrer (5.4). While stirring slowly,
48、 add, in a steady stream,?of the latex containing antioxidant (see 6.5.1). Continue stirring until the latex has completely precipitated and the serum is clear. Continue as described in 6.2.3 and 6.2.4. 7Report The report shall include the following information: a)a reference to this International S
49、tandard; b)all details necessary for complete identification of the test sample; c)whether or not an antioxidant was added, and if so its identity; d)which method (i.e. 6.2, 6.3, 6.4 or 6.5) was used; e)any unusual features noted during the test; f)?full details of any operation not included in this International Standard or in any of the International Standards to which reference is made, together with any operation regarded as