1、 STD-BSI BS EN IS0 305-ENGL 1999 Lb24bh9 0793777 394 M BRITISH STANDARD Plastics - Determination of thermal stability of poly( vinyl chloride) related chlorine-containing homopolymers and copolymers and their compounds - Discoloration method The European Standard EN IS0 305:1999 has the status of a
2、British Standard ICs 83.080.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGH LAW BS EN IS0 305:1999 STD.BSI BS EN IS0 305-ENGL 1999 Lb21iLb 0793778 220 direction of the Sector Board for Amd. No. Materials and Chemicals, was published under the authority of the Standards Committee
3、 and comes into effect on 15 September 1999 0 BSI 09-1999 BS EN IS0 305:1999 Comments National foreword This British Standard is the English language version of EN IS0 3051999. It is identical with IS0 3051990. The UK participation in its preparation was entrusted to Rchnicai Committee PRV21, Testin
4、g of Plastics, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible internationallEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European develop
5、ments and promulgate them in the UK A kt of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists nonnative references to international publications
6、 with their corresponding European publications. The British Stankds which implement intemational 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” facilit
7、y of the BSI Standards Electronic Caalogue. A British Standard does not purport to include all the necessary provisions of a contract Users of British Sandasds are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from iegai obligations.
8、 Summary of pages This document comprises a front cover, an inside front cover, the EN IS0 title page, the EN IS0 foreword page, the IS0 title page, page ii, pages 1 to 4, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when this document was last
9、 issued ISBN O 680 32881 3 STD.BSI BS EN IS0 305-ENGL 1999 lib24bb9 0793779 Lb7 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 305 June 1999 ICs 83.080.00 English version Plastics - Determination of thermal stability of poly(viny1 chloride), related chlorine-containing homopolymers and cop
10、olymers and their compounds - Discoloration method (IS0 305: 1 990) Plastiques - Dtetmination de la SteMlIt thermique du pdy(chl0rure de vinyie), dm homopolymeres et oo(rdymeres chlors apparents et de leurs canpWms - Mthodes du changement de couleur (IS0 3051990) Thk European Standard mis approved b
11、y CEN on 6 May 1999. CEN members are bound to comply with the CENICENELEC Intemal Regulations which stipulate the condllions for gMng 1Ms European Standard the status of a national standard without any alteration. Up-tO-datt3 lists and blbliographical reference9 concerning such national standards ma
12、y be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translabion under the responsibility of a CEN member into Its own language and notified to the Cen
13、tral Secretariat has the same status as the offidei VerdonS. CEN members are the national standards bodies of Austria. Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Itelend, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom
14、. EUROPEAN COMMiTEE FOR STANDARDEATiON COMITE EUROPEEN DE NORMALISATION EUROPAISCHES KOMITEE FOR NORMUNG Ceniml Secretariat: rue de Stassart, 36 B-i050 rus8eis O 1999 GEN All rights of exploitation In any form and by any means resewed worldwide for CEN national Members. Ref. No. EN IS0 305:1999 E EN
15、 IS0 306:1999 Foreword The text of the Intemational Standard from Technical Committee ISOlTC 61 “Plastics“ of the Internatiol Organization for Standardization (ISO) has been taken over as an European Standard by Technical Committee CEN/TC 249 “Plastics“, the secretariat of which is held by IBN. This
16、 European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 1999, and conflicting national standards shall be withdrawn at the latest by December 1999. According to the CENKENELEC Internal Regulations, t
17、he national standards organizations of the following countries 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 Kin
18、gdom. Endorsement notice The text of the International Standard IS0 305:1990 has been approved by CEN as a European Standard without any modification. STD-BSI BS EN IS0 305-ENGL 3999 = Lb24bb9 0793783 815 = EN IS0 306:1999 I N TER NAT I O N AL STANDARD IS0 305 Second edition 1990-04-01 Plastics - De
19、termination of thermal stability of poly(viny1 chloride), related chlorine-containing .homopolymers and copolymers and their compounds - Discoloration method Plastiques - DBtermination de la stabilit thermique du poly(ch1orure de vinyle), des homopolymres et copolymres chlors apparents et de leurs c
20、ompositions - Mthode du changement de couleur Reference number IS0 305: 1990( E) STD.BS1 BS EN IS0 305-ENGL 1999 Lb24bb9 0793382 751 0 EN IS0 306:1999 Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodles). The wor
21、k of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that commlttee. International organizations, govern- mental and non-govern
22、mental, in liaison with ISO, also take pari in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft international Standards adopted by the technical committees are circulated to the member bodies for vot
23、ing. Publication as an Interna- tional Standard requires approval by at least 75 YO of the member bodies casting a vote. International Standard IS0 305 was prepared by Technical Committee ISO/TC 61, Plastics. This second edition cancels and replaces the first edition (IS0 305:1976), of which it cons
24、titutes a technical revision. Descriptors: plastics, polyvlnyi chlorlde, copolymers, thermal tests, determlnatlon, thermal stabillty, dlscoloratlon. ii STD.BSI BS EN IS0 305-ENGL 1779 6 3b24bb9 0793783 b78 6 EN IS0 306:1999 Plastics - Determination of thermal stability of poly(viny1 chloride), relat
25、ed chlorine-containing homopolymers and copolymers and their compounds - Discoloration method 1 scope 1.1 This International Standard specifies two methods for the determination of the thermal stabil- ity of products and compounds based on vinyl chloride homopolymers and copolymers (referred to simp
26、ly as WC in the following text) by the extent of the discoloration that occurs when they are ex- posed, in the form of sheet, to elevated temper- atures. - Method A: Oil-bath method - Method B: Oven method 1.2 These methods are particularly applicable to the determination of the resistance of PVC to
27、 de- gradation by heat, as assessed by the change in coiour after different times of heating under stand- ardized conditions. The results are comparative only, and may be unsatisfactory when coloured PVC materials are tested. 1.3 Method A is a simple method, which requires little expenditure on appa
28、ratus and permits materi- als to be tested almost in the absence of air. Method B requires a forced-air oven, in which the air flow is adjusted to provide a sufficiently uniform temperature throughout the entire test area. This method is not applicable to materials that will cross-contaminate during
29、 oven exposure. The stability times given by the two methods may :rot be similar and cannot be used for direct- Lumparison purposes. 2 Principle 2.1 Method A Oll-bath method A series of test specimens is heated at an elevated temperature for different lengths of time in a temperature-controlled oll
30、bath. The test specimens are placed between an aluminium block and an al- uminium cylinder to promote heat transfer and re- strict air access. 2.2 Method 8: Oven method A series of test specimens is heated at an elevated temperature for different lengths of time in a forced-air-circulation oven. The
31、 test specimens are supported by new, clean aluminium foil laid on re- movable racks. 3 Preparatlon and number of test speclmens 3.1 The test specimens shall consist of - discs of diameter 14 mm and thickness approxi- mately 1 mm, for method A; - squares of side 15 mm and thickness approxi- They sha
32、ll be punched out from the sheets to be tested. mately 1 mm, for method B. 3.2 The number of test specimens required is the expected time of the test in minutes divided by 5. if the stability of the compound is very high, remove the test specimens every 10 to 15 minutes instead of every 5 minutes du
33、ring the first stage of heating, before the appearance of discoloration. Thus, the number of test specimens used can be less than that specified above. 1 - STDoBSI BS EN IS0 305-ENGL 1999 - 1b24bb9 0793781 524 EN IS0 305:1999 3.3 If the material to be tested is an extrusion or moulding material in g
34、ranule, powder or pellet form, this shall be sheeted on a roll-mill under the condi- tions specifled in the material specification, or as agreed upon between the Interested parties (IS0 293:1986, Plastics - Compression moulding test specimens of thermoplastic materials, may be help- ful in this resp
35、ect). 3.4 If the material to be tested is in the form of a paste (plastisol), it shall be gelled to give a well fused sheet; the test specimens shall be punched out from the sheet thus obtained. NOTES 1 If the surface flnlsh of specimens (particularly those made rom unplasticized materials) prepared
36、 by milling does not ensure sucient contact with the aluminium Mock and cylinder, press-polishing of the specimens is recommended as an optional additional step. 2 Warming of the milled unplasticized sheets will permit test specimens to be cut without shattering. I 4 lest temperature The test temper
37、ature shall be that stated in the ma- terial specification or as agreed upon between the Interested parties; In the latter case, the temper- ature shall be chosen so that the test duration is in the range 60 min to 120 min. If there is no specifice- tlon or agreement, a temperature of 180 “C shall b
38、e used. 5 Method A: Oll-bath method 5.1 Apparatus 5.1.1 Thermostacally contrdled oll bath, capable of maintaining the temperature within f 0.5 “C in the range 120 OC to 200 OC, fitted with a suitable stirrer and a suitable device for holding a convenient number of test tubes immersed to a depth of 6
39、0 mm to 70 mm. 5.1.2 Glast test tubes, of the followlng dimensions: - external diameter: 18 mm f 0,4 mm; - wall thickness: 1,2 mm f 0,2 mm; - length: 150 mm minimum. 5.1.3 Alumlnlum blocks, as shown in figure 1. Dlmenslons In mllllmetres Flgure 1 - Alumlnlum black 5.1.4 Alumlnlum cylinders, with a d
40、iameter of 15 mm f 0,s mm and a height of 30 mm. 5.1.5 Tlmlngdevice, for example a stopwatch, with an accuracy of 0,5 min or better. 5.2 Procedure 5.2.1 Prepare a sufficient number of test tubes (5.1.2) and place an aluminium block (5.1.3) in each tube; then inseri a test specimen and cover it with
41、an aluminium cylinder (5.1.4). 5.2.2 Place the test tubes vertically in the oil bath (5.1.1) that has been brought to within 0.5 “C of the specifled or agreed temperature, and start the tim- ing device (5.1.5). 5.2.3 Every 5 min take a test tube from the bath. Remove the test specimen from the tube
42、and allow it to cool, using slight pressure, If necessary, to prevent deformation. Number the test specimens consecutively. 5.2.4 Fasten the test specimens on a card with a note of the exposure time in minutes of each speci- men and the test temperature. WARNING - In order to make handllng of the te
43、st tubes, whlch are covered wlth hot oll, safer after they have been removed from the oll bath, an optlonal drainage and handllng tlme can be agreed upon be= tween the lnbiwted partles. Use tongs or another rubble devlce to hold the tuber when tlpplng out the alumlnlum blocks. 2 - STD=BSI BS EN IS0
44、305-ENGL 1999 1btr)bbT 0793785 Lib0 I 6 Method 8: Oven method 6.1 Apparatus 6.1.1 Forced-alr-clrculation oven, having the fol- lowing additional features: 6.1.1.1 The temperature of the oven shall be controlled by a thermostat capable of maintaining it to within f 0,s “C of the temperature selected.
45、 6.1.1.2 The oven shall be equipped with a cali- brated thermometer and the proper system cor- rection shall be applied to the temperature measurement. 6.1.1.3 The air flow in the oven shall be adjusted to provide a temperature which is sunlciently uniform throughout the test area of the oven that s
46、pecimens of uniform colour are produced (see 6.1.2, second paragraph) This will usually require an air flow of 0,3 mYmin. 6.1.1.4 Prior to the test, the uniformity of the tem- perature within the oven shall be verified. Temper- ature uniformity is usually verified by placing thermocouples near each
47、corner and at the centre; checks are made at 5 min Intervals. It may also be done by inserting, at the test temperature, a rack with 8 to 10 specimens from the same sample dis- tributed over the test area and exposing them until an early stage of discoloration is reached. The for- mulation shall be
48、such as to cause a sharp change in colour within 45 min to 60 min under the test conditions. A non-uniform temperature distribution. as indicated by differences in the colours of the ex- posed specimens, shall be corrected before pro- ceeding with the test. 6.1.1.5 lhe inside of the oven shall be fr
49、ee of con- tamination and surface deposits. Use stainless-steel oven liners to reduce corrosion due to extended ex- posure to decomposition gases. 6.1.2 Speclmen supports, made of new, clean alu- minium foil laid on a removable oven rack (grille). If an oven equipped with a rotating specimen-holder is employed, the specimens shall be supported so that no appreciable elongation or necking down of the test specimens occurs during the test, since this would alter the specimen dimensions, and espe- cially the thickness. In this case, the uniformity of the o
