1、BRITISH STANDARD BS 2782-4: Method 432D: 1995 Methods of testing Plastics Part 4: Chemical properties Method 432D: Determination of styrene evaporation from unsaturated polyester resinsBS2782-4:Method 432D:1995 This British Standard, having been prepared under the directionof the Sector Board forMat
2、erials and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15 August 1995 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PRI/40 Draft for comment 93/314379DC ISBN 0 580 24238 2 Committees responsible for thi
3、s British Standard The preparation of this British Standard was entrusted to Technical Committee PRI/40, Thermosetting resins, prepregs and moulding compounds, upon which the following bodies were represented: BEAMA Ltd. British Plastics Federation Chemical Industries Association Electrical Installa
4、tion Equipment Manufacturers Association (BEAMA Ltd.) European Resin Manufacturers Association Ministry of Defence RAPRA Technology Ltd. Amendments issued since publication Amd. No. Date CommentsBS2782-4:Method 432D:1995 BSI 11-1999 i Contents Page Committees responsible Inside front cover Foreword
5、ii 1 Scope 1 2 Normative references 1 3 Principle 1 4 Apparatus and materials 1 5 Procedure 2 6 Test report 2 Figure 1 Apparatus showing shielding 1 List of references Inside back coverBS2782-4:Method 432D:1995 ii BSI 11-1999 Foreword This British Standard has been prepared by Technical Committee PR
6、I/40. It is based on a method originally published by the British Plastics Federation. A related method is BS 2782:Method 432:1991 Determination of residual styrene monomer content in reinforced plastics based on polyester resins. WARNING NOTE. This British Standard method does not necessarily detai
7、l all the precautions necessary to meet the requirements of the Health and Safety at work, etc. Act 1974. Attention should be paid to any appropriate safety precautions and the method should be operated only be trained personnel. A British Standard does not purport to include all the necessary provi
8、sions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does 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, pages1 and 2, an
9、 inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS2782-4:Method 432D:1995 BSI 11-1999 1 1 Scope This British Standard describes a method for meas
10、uring the rate of loss of styrene from contact moulded materials using unsaturated polyester resins and glass fibre chopped strand mats, with a surface open to the atmosphere. 2 Normative reference This British Standard incorporates, by reference, provisions from a specific edition of another public
11、ation. This normative reference is cited at the appropriate point in the text and the publication is listed on the inside back cover. Subsequent amendments to, or revisions of, this publication apply to this British Standard only when incorporated in it by updating or revision. 3 Principle A single
12、layer of reinforcement is impregnated with resin and supported on a top pan balance in a temperature-controlled room. The loss in mass in g/m 2is recorded graphically against time. 4 Apparatus and materials 4.1 Top pan balance, direct reading, accurate to0.01g. 4.2 Polyethylene terephthalate film 4.
13、3 Glass fibre chopped strand mat, emulsion bound, mass per unit area 450 g/m 2 , in accordance with BS3496. 4.4 Glass beaker, or other wax-free container. 4.5 Support platen, of nominal size 300 mm 300 mm. 4.6 Shielding for apparatus to prevent draughts, in accordance with Figure 1. 4.7 Clock or lab
14、oratory timing device, with an accuracy 1 s. 4.8 Quantity of test resin, having a mass not less than four times the mass of the chopped strand mat (see clause 5). 4.9 Catalyst and/or accelerator, when required (seeclause 5). Figure 1 Apparatus, showing shielding BS2782-4:Method 432D:1995 2 BSI 11-19
15、99 5 Procedure Carry out the test in a room of at least 50 m 3 , with the temperature controlled at 23 C 2 C. Assemble the balance and support platen in accordance with Figure 1. Position the shielding required. NOTEIf the apparatus is assembled in a draught-free room then the shielding is not essen
16、tial. Cut three pieces of glass fibre chopped strand mat of nominal dimensions 250 mm 250 mm and weigh each. Cut three pieces of polyethylene terephthalate film of nominal dimensions 300 mm 300 mm. Mark an area of 250 mm 250 mm on the back of the film with a marking pen. Tape the film, with marked s
17、ide downwards, on to the support platen. Adjust the polyester resin temperature in the glass beaker to 23 C 2 C. If a catalyst is used, catalyse and, if necessary, accelerate the resin and immediately start the clock. Stir the resin for 30 s, then pour a weighed quantity of resin from the glass beak
18、er on to the film, spreading evenly over the marked area. The quantity of resin used is calculated from the mass of the glass fibre chopped strand mat and shall be 2.5 times that mass. Place the piece of mat into the resin and quickly ensure complete impregnation of the mat by gently pressing with t
19、he edge of a spatula. Ensure that there is no free resin beyond the edge of the glass mat. After no more than 2 min, place the assembly consisting of support platen, film and impregnated mat on the top pan balance. Record the initial mass, and the mass after2min,5min, 10 min and then at 10 min inter
20、vals for a total time of 60 min. Longer times may be used by agreement and shall be reported. From the results plot a graph of mean cumulative loss in mass against time. Repeat the procedure for a total of three test assemblies. 6 Test report The test report shall include the following information:
21、a) the name of the testing establishment; b) the date of the test; c) complete identification of the materials tested, resin and glass fibre chopped strand mat, their type, source, manufacturers reference; d) a reference to this British Standard, i.e.determined in accordance with BS2782:Method 432D:
22、1994; e) the atmospheric pressure, temperature and relative humidity at the time of testing; f) the amount of styrene emitted, expressed as mass per unit area of the test piece, (g/m 2 ) after60 min, and a graphical representation of its emission, for each of the three samples tested; g) if a cataly
23、st is used, specify catalyst type and quantity; h) type and quantity of accelerator if used.BS2782-4:Method 432D:1995 BSI 11-1999 List of references (see clause 2) Normative reference BSI publication BRITISH STANDARDS INSTITUTION, London BS 3496:1989, Specification for E glass fibre chopped strand m
24、at for reinforcement of polyester and other liquid laminating systems. BS 2782-4: Method 432D: 1995 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe
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