ISO 4608 pdf download.Plastics — Homopolymer and copolymer resins of vinyl chloride for general use — Determination of plasticizer absorption at room temperature
1 Scope
This International Standard specifies a method for determining plasticizer absorption at room temperature. It is applicable to PVC general-purpose resins and filler resins (designated “G” and “F” in ISO 1 060-1 :1 998, Plastics — Homopolymer and copolymer resins of vinyl chloride — Part 1 : Designation system and basis for specifications ). The object of the test is to determine the quantity of plasticizer absorbed by a resin at room temperature to give a dry mixture. The results give a general indication of the plasticizer absorption of a resin at room temperature. They indicate the usefulness of resins for the manufacture of plasticized dry blends, particularly when taken in conjunction with the results of plasticizer absorption tests under hot conditions.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1 385-1 :1 977, Phthalate esters for industrial use — Methods of test — Part 1 : General.
3 Principle
An excess of bis-(2-ethylhexyl) phthalate (DOP) is added to a specified amount of resin. The mixture is then centrifuged under defined conditions and the amount of plasticizer retained by the resin determined.
4 Apparatus and materials
Ordinary laboratory apparatus, plus the following: 4.1 Balance, capable of weighing to 0,1 mg. 4.2 Burette, for example 50 cm 3 , graduated at 0,1 cm 3 intervals.
4.3 Centrifuge, whose rotor turns in a horizontal plane and which has an acceleration under the test conditions of 24 500 m⋅s –2 to 29 500 m⋅s –2 measured at the bottoms of the tubes, with, if necessary, a cooling system to prevent the temperature of the mixture from exceeding 30 °C at the end of centrifuging for 60 min. NOTE — It is permissible to use different centrifuging conditions, i.e. a different acceleration, a different time and smaller centrifuge tubes (see 4.4), provided that it has been verified that the results obtained are equivalent. 4.4 Centrifuge tubes, to fit the centrifuge used, each consisting either of a tube, made of glass or another material, with a conical bottom pierced by a hole of about 0,8 mm diameter (see figure 1 ) or of a cylindrical tube fitted at one end with a sieve plate on which a filter paper can be placed (see figure 2). The sieve plate is pierced by holes of diameter approximately 0,8 mm. The holes are arranged concentrically approximately 4 mm apart. 4.5 Sheaths, made of polyamide, polyethylene or any other suitable material, to fit the centrifuge used, with a reduction tube at the bottom to support the centrifuge tube (see figure 1 or 2).4.6 Cotton wool, pharmaceutical quality, having a DOP absorption measured under the test conditions (see 5.1 ) of approximately 1 0 %, or, if a centrifuge tube with a sieve plate is used, filter paper, with a diameter is equal to the inner diameter of the centrifuge tube. NOTE — Alternative materials to cotton wool may be used if it can be shown that they produce equivalent results, for example glass wool and PTFE-coated polyester felt.
5 Procedure
5.1 Measurement of DOP absorbed by the cotton wool or filter paper Following the procedure indicated in 5.2, carry out a blank test with a piece of cotton wool having a mass of 1 00 mg ± 2 mg or with a filter paper (if a centrifuge tube with a sieve plate is used), but without any resin. Determine the amount of DOP absorbed by the cotton wool or filter paper, in grams. 5.2 Determination Weigh a piece of cotton wool (1 00 mg ± 2 mg), place it in the centrifuge tube and pack it down slightly. When working with a centrifuge tube with a sieve plate, place a filter paper on the sieve plate. Weigh the tube and cotton wool or filter paper to the nearest 0,1 mg. Weigh directly into the tube 2,000 g ± 0,001 g, to the nearest 0,1 mg, of the resin under test. From the burette, run into the tube 4 cm 3 of DOP and allow it to stand for about 1 0 min. NOTE — If smaller centrifuge tubes are used (see the note to 4.3), the following smaller quantities of material may be used: — 1 g of resin under test; — 2 cm 3 of DOP. Put the tube into its sheath and place the whole into one of the compartments of the centrifuge rotor (the other compartments being occupied by tubes containing other resin samples, all the tubes being balanced). Set the centrifuge to give an acceleration of 24 500 m⋅s –2 to 29 500 m⋅s –2 at the bottoms of the tubes for 60 min. If necessary, switch on the cooling device during centrifuging. The temperature shall not exceed 30 °C. Take the tube from its sheath, carefully wipe it to remove any DOP on the outside and weigh it to the nearest 0,1 mg.