GB/T 1668-2008 (GB/T1668-2008, GBT 1668-2008, GBT1668-2008) & related versions
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GB/T 1668-2008
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.100.40
G 70
Replacing GB/T 1668-1995, GB/T 6489.2-2001
Plasticizers - Determination of acid value and acidity
ISSUED ON. JUNE 4, 2008
IMPLEMENTED ON. DECEMBER 1, 2008
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Principle... 5
4 Reagents and material ... 6
5 Apparatus ... 6
6 Analytical procedures ... 6
7 Result calculation ... 7
Foreword
This Standard was integrated and revised from GB/T 1668-1995 “Plasticizers -
Determination of acid value and acidity” and GB/T 6489.2-2001 “Phthalate
esters for industrial use - Methods of test - Determination of acidity”.
Since the implementation date, this Standard has simultaneously replaced
GB/T 1668-1995 “Plasticizers - Determination of acid value and acidity” and
GB/T 6489.2-2001 “Phthalate esters for industrial use - Methods of test -
Determination of acidity”.
There is no technical difference between this Standard and GB/T 1668-1995.
The technical differences between this Standard and GB/T 6489.2-2001 are as
follows.
- Added in Clause 4 Reagents. ethanol, petroleum ether. distillation range
is 90°C~120°C; petroleum ether - ethanol (anhydrous) mixture. 1+1,
sodium hydroxide standard volumetric solution. c(NaOH)=0.05 mol/L;
potassium hydroxide standard volumetric solution. c(KOH)= 0.02 mol/L,
c(KOH)= 0.05 mol/L; bromocresol purple indicator solution. 1 g/L.
- In Clause 6 Analytical procedures, based on different sample solubility,
this Standard is divided into. determination of acid value and acidity of
plasticizer which contains free acid which is easily soluble in ethanol, and
soluble both in alcohol and water AND determination of acid value and
acidity of plasticizer which contains free acid which is not easily soluble in
ethanol but easily soluble in water.
- In Clause 7 Result calculation, this Standard separately gives calculation
equations of acid value and acidity; while GB/T 1668-1995 only gives
calculation equation of acidity.
This Standard was proposed by China Petroleum and Chemical Industry
Federation.
This Standard shall be under the jurisdiction of Chemical Additives Technical
Subcommittee of National Technical Committee on Rubber & Products of
Standardization Administration of China.
Drafting organization of this Standard. Shanxi Institute of Chemical Engineering.
Main drafter of this Standard. Guo Yanping and Fan Xiuli.
Plasticizers - Determination of acid value and acidity
WARNING – The personnel who use this Standard shall be familiar with regular
laboratory procedures. This Standard is not intended to include all possible
safety issues arising from the use of this Standard. It shall be user’s
responsibility to establish appropriate safety and protection measures, and
determine the adaptive management system.
1 Scope
This Standard specifies the determination method of acid value and acidity of
plasticizers.
This Standard is applicable to the determination of acid value and acidity of
general plasticizers.
2 Normative references
The following standards contain the provisions which, through reference in this
Standard, constitute the provisions of this Standard. For dated references, the
subsequent amendments (excluding corrections) or revisions do not apply to
this Standard. However, the parties who enter into agreement based on this
Standard are encouraged to investigate whether the latest versions of these
documents are applicable. For undated reference documents, the latest
versions apply to this Standard.
GB/T 601 Chemical Reagent - Preparations of Standard Volumetric
Solutions
GB/T 603 Chemical Reagent - Preparations of Reagent Solution for Use in
Test (GB/T 603-2002, ISO 6353-1.1982, NEQ)
GB/T 6682 Water for analytical laboratory use - Specification and test
methods (GB/T 6682-2008, ISO 3696.1987, MOD)
3 Principle
Use ethanol or petroleum ether-ethanol (anhydrous) as solvent to dissolve
sample. Use phenolphthalein as indicator solution. Use sodium hydroxide or
potassium hydroxide-ethanol standard volumetric solution to titrate sample.
plasticizer; its value shall be expressed in %, according to equation (2).
Where,
A - Sample acidity, in % (mass fraction);
V - Volume of sodium hydroxide (potassium hydroxide - ethanol) standard
volumetric solution consumed by the sample, in milliliter (mL);
V0 - Volume of sodium hydroxide (potassium hydroxide - ethanol) standard
volumetric solution consumed by blank test, in milliliter (mL);
c - Exact concentration value of sodium hydroxide (potassium hydroxide -
ethanol) standard volumetric solution, in moles per liter (mol/L);
m - Sample mass value, in grams (g);
MA - Molar mass value of corresponding acid, in grams per mole (g/mol);
nA - COOH of corresponding acid.
......
Standard ID | GB/T 1668-2008 (GB/T1668-2008) | Description (Translated English) | Plasticizers - Determination of acid value and acidity | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | G70 | Classification of International Standard | 71.100.40 | Word Count Estimation | 5,528 | Date of Issue | 2008-06-04 | Date of Implementation | 2008-12-01 | Older Standard (superseded by this standard) | GB/T 1668-1995; GB/T 6489.2-2001 | Quoted Standard | GB/T 601; GB/T 603; GB/T 6682 | Drafting Organization | Shanxi Institute of Chemical Engineering | Administrative Organization | National Rubber and rubber products for Standardization Technical Committee | Regulation (derived from) | National Standard Approval Announcement 2008 No.9 (Total No.122) | Proposing organization | China Petroleum and Chemical Industry Association | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, China National Standardization Administration Committee | Summary | This standard specifies the method for determination of acid value and acidity of the plasticizer. This standard applies to the determination of acid value and acidity general plasticizer. | Standard ID | GB/T 1668-1995 (GB/T1668-1995) | Description (Translated English) | Plasticizers--Determination of acid value and acidity | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | G70 | Classification of International Standard | 87.060.30 | Word Count Estimation | 4,410 | Date of Issue | 1995/1/12 | Date of Implementation | 1995/10/1 | Older Standard (superseded by this standard) | GB 1668-1981; GB 1674-1981; GB 1675-1981 | Regulation (derived from) | Announcement of Newly Approved National Standards No. 9 in 2008 (No. 122 overall) | Proposing organization | Ministry of Chemical Industry of the People Republic of China | Issuing agency(ies) | State Bureau of Technical Supervision | Standard ID | GB 1668-1981 (GB1668-1981) | Description (Translated English) | Determination of the acid value of plasticizer (1) | Sector / Industry | National Standard | Classification of Chinese Standard | G71 | Word Count Estimation | 2,223 | Date of Issue | 1981/10/30 | Date of Implementation | 1982/7/1 |
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