Skip to product information
1 of 6

PayPal, credit cards. Download editable-PDF and invoice in 1 second!

GB/T 7139-2002 English PDF (GBT7139-2002)

GB/T 7139-2002 English PDF (GBT7139-2002)

Regular price $70.00 USD
Regular price Sale price $70.00 USD
Sale Sold out
Shipping calculated at checkout.
Quotation: In 1-minute, 24-hr self-service. Click here GB/T 7139-2002 to get it for Purchase Approval, Bank TT...

GB/T 7139-2002: Plastics -- Vinyl chloride homopolymers and copolymers -- Determination of chlorine content

This standard specifies two methods for determining the chlorine content of vinyl chloride homopolymers and copolymers containing no plasticizers or additives, that is: - Method A (burning bomb); - Method B (burning bottle).
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
ICS 83.080.20 G 32
GB/T 7139-2002
Replacing GB/T 7139-1987
Plastics - Vinyl chloride homopolymers and copolymers - Determination of chlorine content (eqv ISO 1158.1998)
Issued on. September 24, 2002 Implemented on. April 01, 2003
Issued by. General Administration of Quality Supervision, Inspection and Quarantine Foreword ... 3
ISO Foreword ... 5
1 Scope ... 6
2 Normative references ... 6
3 Principles ... 6
4 Reagents and materials ... 6
5 Instruments ... 7
6 Specimen ... 8
7 Steps ... 9
8 Representation of results ... 11
9 Test report ... 12
Appendix A (Informative) Loading method of sodium peroxide, starch or sucrose specimen ... 13
Appendix B (Informative) Determination of chlorine content by Volhard method (method A) ... 14
Appendix C (Informative) Determination of chlorine content by Volhard method (Method B) ... 16
This standard equivalently adopts the international standard ISO 1158.1998 (E) ?€?Plastics -Vinyl chloride homopolymers and copolymers -Determination of chlorine content?€?. It is the revision of the recommended national standard GB/T 7139-1987 ?€?Determination of chlorine content in vinyl chloride homopolymers and copolymers?€?. The main differences between this standard and ISO 1158.1998 (E) are as follows. This standard specifies that the addition amount of sodium peroxide is 10 g ~ 15 g, whilst ISO 1158.1998 (E) specifies that the addition amount of sodium peroxide is 14 g ~ 15 g. This standard provides another method of sample loading in the form of Appendix A. This standard provides the method of chemical analysis in the determination of chlorine content in the form of Appendix B, whilst ISO 1158.1998 (E) does not make detailed specification. The main differences between this standard and GB/T 7139-1987 are as follows. This standard specifies that the addition amount of sodium peroxide is 10 g ~ 15 g, while the original standard specifies that the addition amount of sodium peroxide is 14 g ~ 15 g This standard specifies that the sample weighing accuracy of Method B is 0.01 mg, whilst the original standard specifies this as 0.1 mg.
This standard name is modified according to its correspondence with ISO 1158. This standard shall replace GB/T 7139-1987 from the date of implementation. Appendix A, Appendix B and Appendix C of this standard are informative. This standard was proposed by the China Petroleum and Chemical Industry Association. This standard shall be under the jurisdiction of the National Plastics Standardization Technical Committee Polyvinyl Chloride Resin Products Branch (TC 15/SC 7). Drafting organization of this standard. Jinxi Chemical Research Institute. copolymers - Determination of chlorine content
1 Scope
This standard specifies two methods for determining the chlorine content of vinyl chloride homopolymers and copolymers containing no plasticizers or additives, that is. Method A (burning bomb);
Method B (burning bottle).
2 Normative references
The provisions contained in the following standards constitute provisions of this standard by reference in this standard. At the time of publication, the editions indicated were valid. All standards will be revised and parties using this standard shall explore the possibility of using the latest version of the following standards. GB/T 6682-1992 Water for analytical laboratory use - Specification and test methods 3 Principles
The specimen is oxidized by sodium peroxide (Method A) or gaseous oxygen (Method B), the resulting chloride is then titrated by potentiometric titration or volumetric titration. 4 Reagents and materials
The reagents and water used in this standard are, unless otherwise specified, analytical reagents and level III water or water of equivalent purity in GB/T 6682. 4.1 Nitric acid solution, c (HNO3) = 2 mol/L.
4.2 Silver nitrate standard titration solution, c (AgNO3) = 0.1 mol/L or 0.05 mol/L. For method A only.
7 Steps
7.1 Method A (burning bomb)
7.1.1 In nickel crucible (5.5) (for gas-ignited burning bombs), first PUT in 5 g ~ 7.5 g of sodium peroxide (4.4), or PUT it into the melt cup of the burning bomb (for electric-ignited bomb), then PLACE in about 0.25 g of specimen (accurate to 0.1 mg) and 0.16 g ~ 0.17 g of combustion improver (4.5), MIX it, then PLACE in 5 g ~ 7.5 g of sodium peroxide (4.4). ADD sodium peroxide to the crucible or the melt cup, PERFORM this operation behind a protective screen wall, STIR to mix it, then COVER it, PLACE the crucible into the burning bomb, TIGHTEN the burning bomb. If using the electric-ignited burning bomb, INSTALL the burning bomb, TAP it gently to densify the load. 7.1.2 IGNITE the burning bomb. If using the gas-ignited burning bomb, it shall be placed in a safety furnace. First USE an empty bomb in the safety furnace to adjust the flame, so that the flame is a few millimeters from the bottom of the bomb, then REMOVE the empty bomb. HEAT the sample bomb to 300 ??C ~ 400 ??C for about 10 min, the combustion usually begins at 50 ??C ~ 60 ??C, producing the cracking sound, the bottom of the bomb begins to emit hot light. 7.1.3 COOL the bomb body. If using a gas-ignited bomb, OPEN it and TAKE out the crucible, carefully PLACE it in a beaker (5.7) containing 100 mL of distilled water, USE a watch glass to immediately cover the beaker. When the reaction is stopped, FLUSH the inside of the bomb and the stopper, CONTAIN the flushing solution in the beaker. If using an electric-ignited bomb, COOL it and REMOVE it, OPEN the head and POUR the material into a beaker (5.7) which contains 100 mL of distilled water. PLACE the melt cup horizontally in the same beaker and immediately USE a watch glass to cover it. If the bomb is cooled in water, BE careful not to allow water to come into contact with the joint between the stopper and the bomb body. 7.1.4 HEAT the beaker to bring the material to boiling, then COOL it, REMOVE the crucible and cover or the melt cup and burner, USE water to rinse it, COLLECT the rinsing solution into the beaker. 7.1.5 Slowly ADD 15 mL of concentrated nitric acid (4.3), then ADD nitric acid solution (4.1) while stirring, until the mixture is neutral, then ADD excessively 2 mL of nitric acid solution (4.1). Note. Methyl orange is a suitable indicator for neutralization.
7.1.6 USE water to dilute the material in the beaker to approximately 200 mL, (Informative)
Determination of chlorine content by Volhard method (Method B)
C1 Reagents
C1.1 Silver nitrate standard titration solution, c (AgNO3) = 0.05 mol/L. C1.2 Ammonium thiocyanate standard titration solution, c (NH4SCN) 0.05 m/L. C1.3 Ammonium ferric sulfate solution, 100 g/L.
C2 Instruments
C2.1 General laboratory instruments.
C2.2 Microburette, 10 mL.
C3 Steps
TRANSFER the material in the burning bottle into a 100 mL volumetric flask, ADD 20.00 mL of silver nitrate standard titration solution (C1.1) under full shaking, DILUTE it to the mark, tightly STOPPER the volumetric flask, SHAKE it vigorously for 2 min, to precipitate silver chloride into a block. PLACE the solution to make it clear, USE dry filter paper, beaker and funnel to filter it. DISCARD the initial part of the filtrate, then USE a 50 mL pipette to pipette the filtrate in a 250 mL conical flask, ADD 2 mL of ammonium ferric sulfate indicator (C1.3). USE the ammonium thiocyanate standard titration solution (C1.2) to titrate the solution under constant shaking, until the solution is slightly orange-red. For the materials of the blank burning test, FOLLOW the above steps to make a blank test. C4 Representation of results
C4.1 The chlorine content of the dry material, expressed by mass percentage Xc, is calculated by the formula (C1). Where.
Vc1 -The volume of the ammonium thiocyanate standard titration solution

View full details