This standard specifies the method for determining the conductivity of water extracts of polyvinyl chloride resins using a conductivity meter. GB/T 2915-1999 Determination of the conductivity of water extracts of polyvinyl chloride resins GB/T2915-1999 Standard download decompression password: www.bzxz.net

ICS 83. 080.20
National Standard of the People's Republic of China
GB/T 2915--1999
Determining the conductivity of water extract of poly (vinyl chlaride) resins1999-09-16 Issued
2000-06-01 Implementation
National Quality and Technical Bureau Issued
GB/T29151999
This standard adopts the first clause "Conductivity of water extract" of ASTMDF755:1992 Standard Specification for Vinyl Chloride Resins, and the difference is:
Standard) ASTM3755.1992 adopts AC current bridge and pan-running pool (electric heating). This standard adopts conductivity The principle of the method is the same as that of the conductivity meter and the conductivity electrode.
2) ASYM17551992 requires that the conductivity of high-purity water should be less than 1S/m. The technical standard requires that the conductivity of high-purity water should be less than 3μs.cm.
This standard is a revised version of GB215-1982, a method for determining the reduced conductivity of ethylene oxide resin attached to water. Compared with the previous version, the differences are as follows:
(1) This standard uses a conductivity meter and a conductivity electrode to determine the water extract, and specifies the instrument accuracy and electrode number. The previous version uses a conductivity meter and specifies the instrument type. .
(2) According to the English name of ASTM E1755:1992 and the requirements of GB/T1.1-1U93, the standard name is changed to Determination of specific conductivity of water-extracted polyvinyl resins
(3) A chapter on test report is added.
(4) In terms of editing, the requirements of GB7T1.1-1993 are followed. This standard replaces GB/T291S182 from the effective date. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard was issued by the National Technical Committee for Plastics Standardization This standard was drafted by the Technical Committee on Fluorinated Ethylene (TC15/SC7) of the People's Republic of China. The drafting units of this standard are: Jinxi Chemical Industry Xin'an Institute, Shenyang Chemical Industry Co., Ltd., Tianxiang Donghai Chemical (Group) Co., Ltd., and Wu Chong Chemical Plant.
The main drafters of this standard are: Zhuang Peiyun, Liu Shenhua, Li Zhangqin, Tian Youli, and Shu Shaoyan: This standard was first issued in March 1982.
1 Scope
National Standard of the People's Republic of China
Determination of conductivity of water extract of polyurethane resin (vlayl This standard specifies the method for determining the conductivity of ethylene oxide resin water extracts using an electric conductivity meter. 2 Referenced standards
GB/T2915-1999
G-T2915-152
The provisions contained in the following standards, through reference in this standard, all become the provisions of this standard. When this standard is published, the versions shown are effective. All standards will be revised. Parties using this standard should discuss the possibility of using the latest versions of the following standards. GB/T6682-1992 Specifications and test methods for water used in analytical experiments UB/T8170-1 Rules for rounding off values ​​
3 Definitions
This standard adopts the following definitions:
Conductivity (conducrity), www.bzxz.net
The reciprocal of the value of the electrical conductivity (received) between the two opposite halves of a vertical piece of water with a side length of one centimeter measured at a specified temperature. Unit: S/cm.
4 Principle
The water content of the resin is filtered by a thermal filter for a short time. The high-purity impurities in the resin will increase the conductivity of the water extract. By comparing the difference between the conductivity of the water extract and the conductivity of the high-purity water, the conductivity of the water extract per unit mass is determined. 5 Instruments
General experimental instruments and,
5.t Conductivity seat only: Range t~2S/cm. Degree -1% (FS) 5.2 Conductivity electrode, effective band 0.1,1. 6 Reagents
The reagents used in this standard. When there is no other requirement, all reagents are pure, 61 high-purity water, and the conductivity is less than or equal to 3μ5/cm. 6.2 Alcohol: Put (2.00±0.01)g of resin sample into a flask which has been filled with commercially pure water prepared by Sofo in advance, add (5.0±0.1)ml of propanol, and move the flask to make the resin completely wet. Add (10 ± 1) mL of high-purity water, put a little flour in the conical flask, heat the conical flask on an electric furnace for 5 min. Cool to (23 ± 10 °C). After the resin sinks, insert the conductivity electrode into the water extract of the conical flask. After 30 °C, measure the conductivity of the water extract. At the same time, use 5 mL of isopropanol and 100 mL of high-purity water to measure the blank conductivity of high-purity water according to the above steps:
White result
8.1 The conductivity K of the unit mass of ethylene resin water extract is calculated according to formula (1): K=(K, -K)/m
Wherein, K——unit mass conductivity of ethylene resin water extract, rS/cm\gK, conductivity of water extract: s/cm:
K. —Conductivity of high-purity water: usS/em
——sample mass, 8.
The results are reported as the arithmetic mean of the values ​​of the parallel pairs, and are accurate to the limit. 8.2 Repeatability
The results are valid when the relative difference between the two test results of the same product is less than or equal to 14.7 times. 8.3 Reproducibility
The relative difference between the test results of the same sample and the two laboratories is less than or equal to 17.2%. 9 Test report
The test report shall include the following items:
a) Indication of the use of this standard;
b) Description of the test material;
e) Specifications of the group,
d) Test results;
e) Factors that may affect the results;
f) Test date.
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