BS-2782-4-METHOD-453A-1978 ISO-2561-1974.pdf
《BS-2782-4-METHOD-453A-1978 ISO-2561-1974.pdf》由会员分享,可在线阅读,更多相关《BS-2782-4-METHOD-453A-1978 ISO-2561-1974.pdf(8页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD BS 2782-4: Method 453A: 1978 ISO 2561:1974 Methods of testing Plastics Part 4: Chemical properties Method 453A: Determination of residual styrene monomer in polystyrene by gas chromatography ISO title: Plastics Determination of residual styrene monomer in polystyrene by gas chromato
2、graphy IMPORTANT NOTE. Before reading this method, it is essential to read the foreword, general introduction and instructions to BS 2782, issued separately. UDC 678.5/.8:678.746.22:543.544:547.538.141 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:01:03 GMT
3、+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 453A:1978 This British Standard, having been prepared under the direction of the Plastics Standards Committee, was published under the authority of the Executive Board on 31 January 1978 BSI 11-1999 The following BSI references relate to the w
4、ork on this standard: Committee reference PLC/17 Draft for comment 77/50307 DC ISBN 0 580 10026 X National foreword This method is identical with ISO 2561 “Plastics Determination of residual styrene monomer in polystyrene by gas chromatography” which has been prepared by ISO/TC 61, Plastics. It repl
5、aces method 403B of BS 2782:1970, which is now little used and which is therefore withdrawn. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a British Standard. Some terminology and certain conventions are not i
6、dentical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point (on the baseline) as the decimal marker. Where the words “International Standard” app
7、ear, referring to this standard, they should be interpreted as “British Standard”. WARNING NOTE. This method, which is identical with ISO 2561, does not necessarily detail all the precautions necessary to meet the requirements of the Health and Safety at Work etc. Act 1974. Attention should be paid
8、to any necessary safety precautions, and the method should only be operated by trained personnel. 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 do
9、es not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 3 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated
10、in the amendment table on the inside front cover. Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:01:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 453A:1978 BSI 11-1999i Conten
11、ts Page National forewordInside front cover 1Scope and field of application1 2Principle1 3Reagents1 4Apparatus1 5Preparation of samples1 6Procedure1 7Expression of results3 8Test report3 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:01:03 GMT+00:00 2006, Un
12、controlled Copy, (c) BSI ii blank Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:01:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 453A:1978 BSI 11-19991 1 Scope and field of application This International Standard specifies a method for the
13、determination of the residual styrene monomer in polystyrene by gas chromatography; it may be used also for the simultaneous determination of other volatile aromatic hydrocarbons in polystyrene. It is applicable both to styrene homopolymers and to butadiene modified polystyrene. 2 Principle Dissolut
14、ion of the polymer sample in chloroform or dichloromethane. Precipitation of the polymer by the addition of methanol and injection of a small volume of the remaining solution into a gas chromatograph to obtain separation of styrene and other volatile aromatic hydrocarbons. The solvent contains a kno
15、wn amount of n-butylbenzene as an internal standard for quantitative evaluation. 3 Reagents 3.1 Chloroform or dichloromethane, analytical grade. A small amount of ethanol which may be contained in the chloroform for stabilization does not affect the determination. 3.2 Methanol, analytical grade. 3.3
16、 n-Butylbenzene, of sufficient purity for analytical use. 3.4 Styrene and (if required) other aromatic hydrocarbons such as ethylbenzene, cumene or alpha-methylstyrene of sufficient purity for calibration. Styrene must be freshly distilled and stored at 0 C until required for use. When mixed with an
17、 equal volume of methanol, the styrene shall give a clear mixture. 3.5 Polyethylene glycol, molecular mass 15 000 to 20 000. (Carbowax 15 to 20 M has been found satisfactory.) 3.6 Diatomaceous earth, particle size 210 to 250 m. (Celite, acid-washed grade, has been found satisfactory.) 3.7 Helium, hy
18、drogen, and air as carrier and fuel gases for gas chromatography. For use with the flame ionization detector, nitrogen may be applied as the carrier gas instead of helium. NOTEChanges in carrier gas are permissible only if this has proved to give the same results. 4 Apparatus Normal laboratory equip
19、ment and 4.1 Gas chromatograph, with injection port for liquid samples, flame ionization detector, and recorder. Some other type of ionization detector may be used, and, in exceptional cases, a thermal conductivity detector. The latter, however, entails lower sensitivity. 4.2 Micro-syringe, 1 to 50
20、l. 4.3 Analytical balance 5 Preparation of samples The sample may be taken from material in the form of a powder, pellets or moulding. Large pieces shall be reduced to fragments sufficiently small for weighing a sample amount as close as possible to 1,5 g. 6 Procedure 6.1 Preparation of solvent for
21、the sample Weigh 900 1 mg of n-butylbenzene (3.3) into a 25 ml flask, transfer quantitatively into a 1 000 ml volumetric flask, and dilute to 1 000 ml with chloroform or dichloromethane (3.1). During the dilution process, maintain the liquid at a temperature of 20 0,5 C. 6.2 Preparation of the sampl
22、e solution Weigh, to the nearest 1 mg, 1,5 g of the polymer sample and transfer to a 100 ml conical flask, preferably with a serum cap closure. Add from a pipette exactly 10 ml of the solvent prepared according to 6.1 and kept at 20 0,5 C. After closing the flask, allow the polymer to dissolve, with
23、 shaking if necessary. After complete dissolution, add exactly 5 ml of methanol (3.2) kept at 20 0,5 C, either by a syringe or from a pipette. After vigorous shaking, allow the precipitate to settle. For injection into the gas chromatograph, extract the required amount with the syringe (4.2) from th
24、e supernatant solution. 6.3 Preparation of calibration solutions Prepare solutions for calibration by weighing 600 0,5 mg of n-butylbenzene together with an appropriate amount of styrene or (if required) of another hydrocarbon to be determined, and diluting in a volumetric flask to 1 000 ml with a m
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- BS-2782-4-METHOD-453A-1978 ISO-2561-1974 BS 2782 METHOD 453 1978 ISO 2561 1974
链接地址:https://www.31doc.com/p-3732598.html