BS 2782-7 Method 732D-1999 Methods of testing plastics - Rheological properties - Determination of the viscosity of polycarbonate (PC) moulding and extrusion materials in dilute so.pdf

1、BRITISH STANDARD BS 2782-7: Method 732D: 1999 ISO 1628-4: 1999 Testing of plastics Part 7: Rheological properties Method 732D: Determination of the viscosity of polycarbonate (PC) moulding and extrusion materials in dilute solution using capillary viscometers ICS 83.080.20BS2782-7:Method 732D:1999 T

2、his British Standard, having been prepared under the directionof the Sector Committeefor Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 August 1999 BSI 03-2000 ISBN 0 580 32874 0 National foreword This British Standard reproduces ver

3、batim ISO 1628-4:1999 and implements it as the UK national standard. It supersedes BS 2782-7:Method 732D:1991 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics, which has the responsibility to: aid enquirers to understand the

4、 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 this comm

5、ittee 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”, or by u

6、sing 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 immuni

7、ty from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages 1 to 7 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indic

8、ated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS2782-7:Method 732D:1999 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 1628-4 1ii blankBS2782-7:Method 732D:1999 ii BSI 03-2000 Contents Page

9、Foreword iii 1 Scope 1 2 Normative references 1 3 Definitions and units 1 4 Principle 2 5 Apparatus 2 6 Solvent and preparation of test solution 2 7 Measurement temperature 3 8 Procedure 3 9 Calculation of results 3 10 Test report 3 Annex A (normative) Instrument-calibration procedures 4 Figure A.1

10、Determination of the effective kinetic-energy correction 5 Figure A.2 Determination of the relative viscosity using standards 6BS2782-7:Method 732D:1999 BSI 03-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO membe

11、r 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 represented on that committee. International organizations, governmenta

12、l 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. Draft International Standards adopted by the technical committees are circulated to the membe

13、r bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 1628-4 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materials. This second edition cancels and

14、 replaces the first edition (ISO 1628-4:1986), which has been technically revised. ISO 1628 consists of the following parts under the general title Plastics Determination of the viscosity of polymers in dilute solution using capillary viscometers: Part 1: General conditions; Part 2: Poly(vinyl chlor

15、ide) resins; Part 3: Polyethylenes and polypropylenes; Part 4: Polycarbonate (PC) moulding and extrusion materials; Part 5: Thermoplastic polyester (TP) homopolymers and copolymers; Part 6: Methyl methacrylate polymers. Annex A forms an integral part of this part of ISO 1628.iv blankBS2782-7:Method

16、732D:1999 BSI 03-2000 1 1 Scope This part of ISO 1628 describes the conditions necessary for the determination of the viscosity number (also known as the reduced viscosity) and the relative viscosity of polycarbonates in dilute solution. It can be used for pure polycarbonates and blends with other p

17、olymers, as well as mixtures of both, with or without fillers, as defined in ISO 7391-1. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 1628. At the time of publication, the editions indicated were va

18、lid. All standards are subject to revision, and parties to agreements based on this part of ISO 1628 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standar

19、ds. ISO 1628-1:1998, Plastics Determination of the viscosity of polymers in dilute solution using capillary viscometers Part 1: General principles. ISO 3105:1994, Glass capillary kinematic viscometers Specifications and operating instructions. ISO 4793:1980, Laboratory sintered (fritted) filters Por

20、osity grading, classification and designation. ISO 7391-1:1996, Plastics Polycarbonate (PC) moulding and extrusion materials Part1:Designation system and basis for specifications. ISO 7391-2:1996, Plastics Polycarbonate (PC) moulding and extrusion materials Part2:Preparation of test specimens and de

21、termination of properties. 3 Definitions and units The viscosity number VN is defined as where The units of VN are mlg 1 . Due to the fact that there is only a slight difference between the density of the solution 0and that of the solvent , can be replaced by v in the formula for calculating the red

22、uced viscosity. The relative viscosity of the solution relis defined as where The relative viscosity is a dimensionless quantity. is the dynamic viscosity of the solution, in Pas; 0 is the dynamic viscosity of the solvent, in Pas; is the density of the solution, in kgm 3 ; 0 is the density of the so

23、lvent, in kgm 3 ; is the kinematic viscosity of the solution, in m 2 s 1 ; is the kinematic viscosity of the solvent, in m 2 s 1 ; c is the concentration of the solution, ingml 1 . is the kinematic viscosity of the solution, in m 2 s 1 ; is the kinematic viscosity of the solvent, in m 2 s 1 ; v - =

24、v 0 0 0 - = rel v v 0 - = v - = v 0 0 0 - =BS2782-7:Method 732D:1999 2 BSI 03-2000 4 Principle (see also ISO 1628-1:1998, clause 4) The kinematic viscosity v is calculated from the following equation: where NOTEContrary to the instructions in ISO 1628-1:1998, clause4, the kinetic-energy correction c

25、an only be ignored if it is not more than 0,2 % of the efflux time t. 5 Apparatus (see also ISO 1628-1:1998, clause 5) 5.1 Viscometer: a) Ubbelohde capillary viscometer, capillary size number 0C, capillary diameter 0,36 mm, receiver flask 2 ml, as specified in ISO 3105. b) Other viscometers listed i

26、n ISO 3105, provided that the same values are obtained as with the viscometer specified above. c) When using automatic viscometers with suitable automatic timing devices (see below), identical results are obtained even if capillaries with a larger diameter (e.g. 0,58 mm) are used (cf.ISO 1628-1, Tab

27、le 1), which means that other capillaries can be used in conjunction with this type of apparatus. In cases of doubt, a viscometer conforming to the requirements given in a) shall be used. The viscometer shall be calibrated by the method described in Annex A. 5.2 Timing device, capable of being read

28、to the nearest 0,1 s and accurate to within 0,1 % over a15-minute period, except when using automatic viscometers with larger-diameter capillaries see5.1, item c) when the timing device shall be capable of being read to the nearest 0,01 s and be accurate to within 0,1 % over a 15-minute period. 5.3

29、Thermostatic bath, operated at 25 C. Temperature fluctuations may not exceed 0,1 C. 5.4 Volumetric flasks, volume 100 ml at the temperature of calibration, fitted with a ground-glass or plastic stopper giving an airtight seal. 5.5 Analytical balance, accurate to 0,1 mg. 5.6 Drying oven, operated at

30、110 C. 5.7 Petri dishes 5.8 Sintered-glass filter crucible, porosity class P1,6 (see ISO 4793). 5.9 Sintered-glass filter crucible, porosity class P4 (see ISO 4793). 5.10 Filter aid, e.g. kieselguhr or diatomaceous earth. 5.11 Laboratory shaker 5.12 Laboratory centrifuge 6 Solvent and preparation of

31、 test solution (see also ISO 1628-1:1998, clause 6) 6.1 Solvent Dichloromethane, of recognized analytical purity, or equivalent. 6.2 Sampling Carry out sampling in such a way that the sample taken is representative of the whole material. 6.3 Concentration of solution The concentration of polycarbona

32、te in the solution shall be 5 g/l. 6.4 Preparation of the test solution 6.4.1 Non-reinforced samples containing little or no pigment/additive Using the analytical balance (5.5), weigh, to the nearest 0,1 mg, 500 mg of the test material into a100 ml volumetric flask (5.4). Add approximately70 ml of d

33、ichloromethane (6.1) and place on the shaker(5.11) until completely dissolved. Make up to the mark with dichloromethane at the calibration temperature, and shake once more to homogenize the solution. When testing materials containing small amounts of pigments and/or additives (see below), increase t

34、he mass of the sample in proportion to the amount of pigment or additive present so that the resulting concentration of pure polycarbonate is 5 g/l. NOTE 1This correction is only necessary if the pigment and/or additive content is more than 1 %. Soluble dyes, pigments and/or additives at concentrati

35、ons of less than 1 % will not affect the result of the determination. NOTE 2Higher concentrations of pigments/additives or very intense dyes (preventing optical measurements using photo-electric cells) affect the measurement so much that these components must be removed from the test solution with t

36、he help of a filter aid (5.10) or centrifuge (5.12). The instructions given in6.4.2 are applicable to the treatment of the sample in such cases. NOTE 3When using an automatic viscometer with computerized control equipment 5.1 c), the amount of polymer weighed out can differ from the set value by up

37、to 10 %, as long as the polymer concentration, which will also differ from the set value, is taken into account when calculating the result see A.3 c). k is the viscometer constant, in ml 2 .s 2 ; t is the efflux time, in s; %t is the kinetic-energy correction, in s; is the density of the solution,

38、in kgm 3 . v -kt%t () = =BS2782-7:Method 732D:1999 BSI 03-2000 3 6.4.2 Glass-fibre-reinforced samples and/or samples with high pigment/additive contents Weigh approximately 5 g of the material under test into a 100 ml volumetric flask (5.4). Add approximately 70 ml of dichloromethane and place on th

39、e shaker until completely dissolved. The sample can be crushed mechanically before this step to increase the speed of dissolution. Allow the insoluble components (glass fibres, pigments, etc.) to settle out and filter the solution through a P4 filter crucible (5.9) into a Petri dish(5.7). Place the

40、Petri dish in the drying oven(5.6) operated at 110 C to evaporate off the dichloromethane. Leave the film which remains in the drying oven until it reaches constant mass (1 h to 10 h, depending on the thickness of the film). Prepare a solution from the dried film using the procedure described in 6.4

41、.1. 7 Measurement temperature The measurement temperature shall be 25 C 0,1 C. 8 Procedure (see also clause 3 and ISO1628-1:1998, clause 8) Pour pure solvent into the viscometer (5.1) through a P1,6 filter crucible (5.8). Determine the flow time of the solvent three to five times at 25 C 0,1 C. The

42、individual measurements shall not differ from their mean value by more than 0,2 %. Repeat the procedure using the sample solution. 9 Calculation of results (see also ISO1628-1:1998, clause 9) Calculate the viscosity number, expressed in ml/g, using a) the method described in A.3; or b) the following

43、 equation: where NOTEThis equation conforms to the relationship defined in ISO1628-1, but additionally takes the kinetic-energy correction into account. This correction is necessary in order to obtain accurate results with the capillaries specified. Equation (12) given in ISO 1628-1:1998, which, usi

44、ng the symbol VN instead of I, reads can be applied with sufficient accuracy if a viscometer with a comparatively thin capillary is used since the kinetic-energy correction term constitutes less than 0,2 % of the efflux time. Calculate the relative viscosity of the solution rel(dimensionless) as fol

45、lows: where Clauses A.1 and A.2 describe how to determine the correction terms %t and %t 0 . 10 Test report This document (test certificate) is described in ISO1628-1:1998, clause 10. v is the kinematic viscosity of the solution, inm 2 s 1 ; v 0 is the kinematic viscosity of the solvent, inm 2 s 1 ;

46、 t is the arithmetic mean of the flow times for the solution, in s; t 0 is the arithmetic mean of the flow times for the solvent, in s; c is the concentration of the solution, ingml 1 ; %t is the kinetic-energy correction for t, provided by the manufacturer of the capillary, in s; %t 0 is the kineti

47、c-energy correction for t 0 , provided by the manufacturer of the capillary, in s. v is the kinematic viscosity of the solution, inm 2 s 1 ; v 0 is the kinematic viscosity of the solvent, inm 2 s 1 ; t is the arithmetic mean of the flow times for the solution, in s; t 0 is the arithmetic mean of the

48、 flow times for the solvent, in s; %t is the kinetic-energy correction for t, provided by the manufacturer of the capillary, in s; %t 0 is the kinetic-energy correction for t 0 , provided by the manufacturer of the capillary, in s. VN tt 0 t 0 C - =BS2782-7:Method 732D:1999 4 BSI 03-2000 Annex A (no

49、rmative) Instrument-calibration procedures A.1 Checking the accuracy of the viscometer Experience has shown that the high level of accuracy necessary when determining the viscosity number of polycarbonate solutions cannot always be reached by commercially available Ubbelohde viscometers. The reason for this lies in small irregularities in the capillaries. It is therefore necessary to check the ac