1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58in polypropyleneICS 83.080.01Plastics Determination of xylene-soluble matter BRITISH STANDARDBS ISO
2、 16152:2005BS ISO 16152:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 3 October 2005 BSI 3 October 2005ISBN 0 580 46568 3Cross-referencesThe British Standards which implement international publications referred to in this document may b
3、e found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are
4、responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 7 and a back cover.The BSI c
5、opyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on request to its secretary.enquiries on the interpretation, or proposals for change,
6、and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 16152:2005 and implements it as the UK national standard.The UK participation in its preparation was entrusted to Techn
7、ical Committee PRI/82, Thermoplastic materials, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any Reference numberISO 16152:2005(E)INTERNATIONAL STANDARD ISO16152First edition2005-07-01Plastics Determination of xyle
8、ne-soluble matter in polypropylene Plastiques Dtermination des matires prsentes dans le polypropylne solubles dans le xylne BS ISO 16152:2005ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Terms and definitions. 1 3 Apparatus 1 4 Reagents 2 5 Procedure 2 5.1 Preparation of the xylene. 2
9、 5.2 Determination of level of impurities in the xylene (solvent blank) 2 5.3 Determination of percentage xylene-soluble matter in the polypropylene 3 6 Calculations. 6 7 Precision and bias 6 8 Test report . 7 BS ISO 16152:2005iv Foreword ISO (the International Organization for Standardization) is a
10、 worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represente
11、d on that committee. International organizations, governmental and 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. International Standards are draf
12、ted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Sta
13、ndard 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. ISO 16152 was prepared
14、by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materials. It replaces ISO 6427:1992, Annex B, which has been technically revised. The revised method tightens the physical parameters of the test to provide improved repeatability and reproducibility. BS ISO 16152:2005vInt
15、roduction This International Standard specifies a method for the quantitative determination of those components of polypropylene that are soluble in xylene. This new method defines more precisely the factors that have the greatest influence on the repeatability and reproducibility of the determinati
16、on. The polypropylene is dissolved in hot xylene, then cooled under controlled conditions down to 25 C, which results in the precipitation of the insoluble fraction. The soluble matter remains in the xylene. The xylene is then evaporated and the residue weighed. The solubles content of polypropylene
17、 is important as it has a major influence on the properties of the polypropylene. BS ISO 16152:2005blank1Plastics Determination of xylene-soluble matter in polypropylene 1 Scope 1.1 This International Standard specifies a method for determining the mass fraction of a polypropylene homopolymer or cop
18、olymer which is soluble in xylene at 25 C. 1.2 A weighed amount of dried sample is dissolved in xylene under reflux conditions, then cooled under controlled conditions and maintained at 25 C to ensure controlled crystallization of the insoluble fraction. 1.3 The xylene-soluble fraction is then recov
19、ered by evaporation of the xylene and determined by weighing the residue. 1.4 Other materials with solubilities similar to that of the xylene-soluble fraction, such as additives, may interfere with the determination. 2 Terms and definitions For the purposes of this document, the following terms and
20、definitions apply. 2.1 xylene-soluble fraction Ssthat percentage, by mass, of the polymer that does not precipitate out when a solution of the polymer in xylene is cooled from reflux temperature to +25 C and held at that temperature for a specified period of time 3 Apparatus 3.1 Reflux condenser, le
21、ngth 400 mm. 3.2 Flat-bottomed flask, capacity 400 ml, with one or two necks, or conical flask or cylindrical bottle of similar capacity. 3.3 Insulating disc, made of fibreglass or mineral wool. 3.4 Magnetic stirrer, with temperature-controlled hotplate, thermostatted oil bath or heating block capab
22、le of maintaining 140 C to 150 C. 3.5 Stirrer bar. 3.6 Pipette, class A, 200 ml or equivalent. 3.7 Pipette, class A, 100 ml or equivalent. 3.8 Glass-stoppered flask, 250 ml. BS ISO 16152:20052 3.9 Thermostatically controlled water bath, with sufficient cooling capacity to maintain a constant bath te
23、mperature of 25 C 0,5 C while cooling down the flask containing the xylene/polymer solution (see 5.3.8 and 5.3.9). 3.10 Filter paper, fluted, Whatman No. 4, No. 541 or equivalent, at least 125 mm in diameter. 3.11 Funnel, 60, or equivalent, at least 125 mm in diameter. 3.12 Vacuum oven. 3.13 Disposa
24、ble aluminium pans, 300 ml capacity, with smooth sides. 3.14 Temperature-controlled hotplate. 3.15 Analytical balance, with a minimum weighing sensitivity of 0,1 mg (a sensitivity of 0,01 mg is preferred). 3.16 Desiccator, containing an appropriate desiccant. 3.17 Timer, preferably with an alarm, re
25、ading in minutes. 3.18 Oven, conventional forced-air or gravity-convection type. 4 Reagents 4.1 Reagent-grade ortho-xylene (o-xylene), assay by gas chromatography (GC) 98 % min.; ethylbenzene content as determined by GC less than 2 %; evaporation residue at 140 C less than 0,002 g/100 ml; boiling po
26、int 144 C. or 4.2 Reagent-grade para-xylene (p-xylene), assay by gas chromatography (GC) 98 % min.; ethylbenzene content as determined by GC less than 2 %; evaporation residue at 140 C less than 0,002 g/100 ml; boiling point 138 C. Reagent-grade ortho-xylene (4.1) shall be used as the reference solv
27、ent whenever there is a dispute between laboratories on test results, unless the laboratories agree otherwise. 5 Procedure 5.1 Preparation of the xylene 5.1.1 Although stabilization of the xylene is not required, antioxidants shall be added to prevent degradation when testing unstabilized powders or
28、 beads. Butylated hydroxytoluene (BHT), 4,4-thiobis(6-tert-butyl-m-cresol) and tetrakismethylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane at an approximate concentration of 0,02 g/l of xylene have been found to be effective stabilizers. Agitate with a magnetic stirrer bar and heat for a min
29、imum of one hour at 80 C to 90 C to ensure thorough mixing of the antioxidants and the xylene. This heating temperature has been chosen as it is suitable for BHT, which is relatively volatile. 5.1.2 Degas the xylene every 24 h by purging with nitrogen gas for a minimum of 1 h. 5.2 Determination of l
30、evel of impurities in the xylene (solvent blank) 5.2.1 The purpose of the solvent blank is to determine the evaporation residue, i.e. the amount of foreign matter in the xylene. BS ISO 16152:20053A blank test should preferably be run on every new batch of xylene. If, however, the xylene is extra-pur
31、e grade (minimum 99,5 %) and is used immediately after being opened, a blank test is not necessary. If all the xylene is not used immediately (within 3 days), a blank test shall be run. It is recommended that xylene be purchased in glass or glass-lined containers of a size such that the xylene will
32、be used within 3 days of opening. Containers of larger size may be used if the xylene is used up within a short period of time. The purpose of this time limit is to ensure purity and minimize pick-up of moisture and other contaminants. Carry out the blank test in triplicate, taking three test portio
33、ns from each bottle or batch of xylene. 5.2.2 Pipette a 200 ml test portion of unstabilized or stabilized xylene into a clean, empty flask. 5.2.3 Place a filter paper or equivalent (3.10) in a funnel (3.11) in a funnel rack over a 250 ml flask (3.8). 5.2.4 Pour the 200 ml of xylene into the funnel a
34、nd allow the filtrate to drip into the flask. Continue the filtration until all the filtrate has been collected. 5.2.5 Dry an aluminum pan (3.13) for 30 min in an oven (3.18) at 200 C. Allow the pan to cool to room temperature in a desiccator (3.16). Weigh the clean, dry pan to the nearest 0,1 mg. 5
35、.2.6 Using a pipette, transfer a 100 ml aliquot of the filtered xylene into the weighed aluminum pan. 5.2.7 Place the pan on a hotplate (3.14) maintained at 140 C to 150 C. Allow the xylene to boil gently to avoid splashing. Blanket the pan with a slow stream of nitrogen. Continue heating until the
36、residue in the pan is almost dry. 5.2.8 Place the pan in a vacuum oven (3.12) at 100 C 10 C at a pressure less than 13,3 kPa for a length of time known to be sufficient to dry the residue to constant mass. 5.2.9 Allow the pan to cool to room temperature in the desiccator, then weigh to the nearest 0
37、,1 mg. 5.2.10 Calculate the average of the results of the three determinations. 5.3 Determination of percentage xylene-soluble matter in the polypropylene NOTE The procedure is described for the particular case of a magnetic stirrer with a hotplate (see 3.4) and a flat-bottomed flask (see 3.2). 5.3.
38、1 If necessary, dry the sample before analysis. For drying, use a vacuum oven at 70 C 5 C at a pressure less than 13,3 kPa for a minimum of 20 min. Allow the sample to cool in a desiccator to prevent moisture pick-up. NOTE Polymer flakes and beads are dried before testing to eliminate moisture that
39、can influence the initial mass of the test portion. With large pellets or beads, where there is concern that the test portion will not dissolve in a reasonable timeframe, the pellets or beads may be ground to an appropriate size to ensure faster dissolution. Care shall be taken not to mechanically s
40、hear the polymer chains or to increase the level of xylene-soluble matter. Dry the ground material as specified above in this subclause. 5.3.2 Weigh out a test portion of the size given in Table 1, except when the expected soluble-matter content is unknown or referee testing between laboratories is
41、being conducted. In such cases, use a test portion of 2,0 g 0,1 g. Weigh the test portion to the nearest 0,1 mg. Pour the test portion into a flat-bottomed flask. Place a magnetic stirrer bar in the flask. 5.3.3 Pipette 200 ml of unstabilized or stabilized xylene into the flask. NOTE Larger quantiti
42、es may be used in the case of test portions that are difficult to dissolve or filter and/or when a larger amount of filtrate is needed for further analysis. BS ISO 16152:20054 5.3.4 Attach the flask to the condenser. 5.3.5 Place an insulating disc on top of the magnetic-stirrer hotplate to prevent l
43、ocalized heating of the flask. Position the flask and condenser on top of the insulating disc (see Figure 1). Insert the nitrogen supply tube in the top of the condenser. Turn on the cooling water to the condenser. Key 1 nitrogen flow 2 reflux condenser 3 flat-bottomed flask 4 conical flask 5 stirre
44、r bar 6 insulating disc 7 magnetic stirrer with temperature-controlled hotplate Figure 1 Examples of equipment set-up 5.3.6 Blanket the contents of the flask with a slow flow of nitrogen directed across the top of the condenser, not directly into the condenser, to minimize possible xylene loss. The
45、nitrogen flow rate should preferably be approximately 2 l/h. 5.3.7 Heat the polymer/xylene mixture to the reflux temperature while stirring. Stirring shall be vigorous enough to obtain a deep vortex, which keeps the boiling under control and prevents the mixture boiling up into the condenser. Once t
46、he reflux temperature is reached, continue to stir for 30 min. The liquid should be perfectly clear. Ensure that refluxing is gentle so that no localized burning or sticking of the polymer to the flask walls occurs. BS ISO 16152:20055NOTE If a hotplate is used, it should preferably be used at a temp
47、erature setting of approximately 30 C above the boiling point of xylene. Table 1 Size of test portion Expected soluble-matter content Test portion mass g 30,0 % by mass 4,0 0,1 or 2,0 0,1 2,0 0,1 2,0 0,1 or 1,0 0,1 5.3.8 Remove the hotplate from beneath the flask. Detach the flask from the condenser
48、 and cover. Allow the solution in the flask to cool in air from the reflux temperature to below 100 C (this will normally take 12 min to 14 min). 5.3.9 Transfer the flask to a thermostatically controlled water bath at 25 C 0,5 C. Do not shake the flask to break up any precipitate before immersing th
49、e flask in the bath. Do not shake the flask while the polymer solution is still hot as this may create a safety hazard. 5.3.10 Without stirring, cool the solution for 30 min in the bath at 25 C 0,5 C. Use a timer, preferably with an alarm, to ensure that the time allowed for precipitation of dissolved polymer from the solution is between 30 min and 32 min. Remove the flask from the bath. Stir or gently shake the flask to break up any precipitated-polymer gel. NOTE The rate of coolin
