This standard specifies the determination method of volatile fatty acid value of concentrated natural rubber latex. This standard is applicable to concentrated natural rubber latex produced from Hevea brasiliensis latex. GB/T 8292-2001 Determination of volatile fatty acid value of concentrated natural rubber latex GB/T8292-2001 Standard download decompression password: www.bzxz.net

GB/T8292—2001
This standard adopts the same method as GB/T8292:1092 for determination of volatile fatty acid value of latex.
The main differences between this standard and the previous version are as follows:
Using oxycarbon as the standard titration solution in the determination of sebum reduction, instead of the previous version using oxycarbon as the standard titration solution;
The average test period is changed to 10mJ.
Added the procedure for removing carbon monoxide from the carbon monoxide-free filter, added Chapter 3 "Definition", changed the "Sample Preparation" and "Determination Method" of the previous version into "Operation Procedure"; cancelled the determination of the volatile fatty acid value of the natural product, and made corresponding changes. This standard replaces GB/T8292—1987. The standard was proposed by the Ministry of Agriculture of the People's Republic of China. This standard was issued by the National Technical Committee for Standardization of Rubber and Rubber Products, the Technical Committee of the Natural Rubber Division of the National Rubber and Rubber Products Standardization Committee, and the Ministry of Industry and Information Technology Product Quality Supervision, Inspection and Testing Center (Weigong). The drafters of this standard are Deng Yifeng, Huang Maofang, and Guilan. This standard is the second edition, and the first edition was first issued in November 2005. This standard is entrusted to the National Technical Committee for Standardization of Rubber and Rubber Products for interpretation. The International Standardization Organization (ISO) is a worldwide joint organization of national standardization organizations (ISO members). The work of formulating international standards is usually carried out by technical committees. Any member body interested in the subject of an established technical committee has the right to participate in that committee. All political and international non-governmental organizations in contact with ISO may also participate in this work. On all aspects of electrotechnical standardization, ISO collaborates closely with the International Technical Committee (FEC). Draft international standards developed by the technical committees are circulated to the member bodies for voting and publication as international standards. A vote of at least 75 % of the member bodies casting a vote is required. International standards ISO 5126 were prepared by ISO/TC45 Technical Committee on Rubber and Rapid Adhesive Products SC Rubber Industrial Raw Materials (including cavity emulsions). The first edition of the wood standard revised the second edition (15) 506:1:85) and replaced the first edition. Tiwei
hJibeixiaoshu
Standards and Technology Network
978060
Species Whole Book Distribution
Data Download
7A Tool Kit
1 Model Chart
National Standard of the People's Republic of ChinaWww.bzxZ.net
Determination of volatile fatty acid number in concentrated natural rubber latexNaiural ruhher ntex concentrateDeterminatinn of volatile futty acid number This standard specifies the inductively coupled method for the determination of volatile fatty acid number in concentrated natural rubber latex. This standard is applicable to the natural latex produced from the latex of the Brazilian rubber tree. 2 Reference Standards
GA/T 8292--2007
IdtIS506:1992
Replaces GB/T62H2-19R7
The following internationally certified articles are all referenced in this standard and become the articles of the standard: When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should consider the possibility of using the latest versions of the following standards. B0-1987 Natural liquid rubber latex (MEG [S0123: 1985) Determination of total solids content of concentrated natural latex GB/T 8298-2001
GB/T829920u1 Determination of total solids content of concentrated natural latex (IDT150126: 1995) NY371987 Natural latex nomenclature (formerly GB7951-1587) 3 Definitions
This standard adopts the following definitions
Volatile fatty acid (VFA) value of concentrated latex
The number of grams of potassium hydroxide required to neutralize the volatile fatty acids in the rubber containing 100% of the total solids. VY97-1987 4.7: If the latex has been added with a substance that has been extracted by sulphation, the volatile fatty acid content is estimated to be high and cannot be expressed without calibration.
After the sample is solidified by the acid method, a part of the separated emulsion is treated with sulfuric acid. The acidified emulsion is steam evaporated, and the extract is then determined by standard alcohol to measure the emulsion in the sample. .5 Reagents
Use fully deionized water or water with the same purity as the sample. 5.1 Ammonium sulfate, about 30.5% (m/m) liquid 5.2 Consistent, about 1.5% (m/m) liquid.
5.3 The standard titration of the lead oxide flag is reduced by c[Ba(OH), 1=0.005ma1/., and it is calibrated by potassium o-formate titration method and stored in a small container without any oxidation state.
5.4 Indicator solvent, 100% phenol or spirit solution, with approximately equal volumes of alcohol-free and water to make a 0.5%/m3 mixture. The General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China approved the standard on July 20, 2001. Technical website
200 12-01 real shot
various certification industry information free download teaching
6 collection
common laboratory instruments and:
GB/T 82922007
) Steam evaporator (Markm: tank), as shown in Figure 1, can be a frosted glass joint between the steamer and the condenser;
b) steam or water gap, can maintain 70: standard group + c) transfer concentration tube, capacity is 5ml..10ml.25mL and 50mL) titration, capacity is appropriate.
single: m
frosted glass whole
suspended steam outlet
outer diameter 29~813~14
[1--15[1.
for sampling
1. 5n. 75~-1. 250. 75 -.-. 25 1--1. 51
according to the method specified in GB/T82SC.
8 Operation sequence
Lengsen Benshan
Bud water mouth
15-~1720~22
. 75 -- 1. 251. 5 - 9
Hot steam heater (atkham steamer)
11·~12
. 75 ~1. 25D. TE ~-1. 25
8.1 If the total solid content and liquid content of the latex are unknown, they shall be determined according to GB/TA298 and GB/TR299 respectively. Take about 50g of concentrated latex and pour it into a 0.1g filter beaker. Stir the concentrated latex while adding 50ml of ammonium sulfate (5.2). Place the beaker in a steam bath (6.2) or a water bath (6.3). Control the temperature at 70°C and continue to stir the latex until it is completely coagulated. Cover the beaker with a surface layer of blood and continue to stand in the steam or water bath for a total of 13 minutes. Slowly add water. ||The whey is filtered through a paper filter: the curd is poured into the mortar, more milk is extracted with a mortar, the whey is thinned through the above-mentioned evaporation paper, 25 mL of the evaporation waste is pipetted into a 50 mL flask, and 50 mL of sulfuric acid concentrate (5.2) is added to acidify, and the mixture is returned to the main flask to be mixed evenly.
For some concentrated wax latexes, especially concentrated yogurt preserved with potassium hydroxide, fine precipitates will form during emulsification. A new card should be used to remove the large precipitates before distillation. Let the steam pass through the evaporator (6.1) for at least 15 minutes, then let the steam pass through the outer tube of the evaporator (the steam outlet is open) and at the same time use a pipette [6.4) to draw 1 liter of acidified whey into the inner tube: if it is serious, add a drop of appropriate anti-foaming agent. Place the effluent under the tip of the condenser or in a 10 cm volumetric tube, partially close the steam port and continue to evaporate at a rate of 3 ml/min to 5 ml/min until 100 ml of effluent is collected. Transfer the effluent to a 36 mL conical flask and then pass a stream of pure air through it at a rate of 200 mE/min to 30 mL/min for about 10 min to remove any carbon dioxide dissolved in the effluent. Assay with sodium hydroxide solution (5.3) using one of the specified indicators (5.1) as the indicator, 8.3 Collect 50 more samples of shrinkage latex for more repeated determination (8.2). 9 Expression of wax
Use the formula to calculate the value of volatile fatty acids (VFA) VFA
134-64
The actual concentration of the oxidized compound (53) is the volume of the required ion hydroxide solution for neutralization, ml; the mass of the formula B!
The latex content is expressed as mass fraction: According to the total solid content of the initial latex. The concentration is expressed as mass fraction. The concentration is calculated from the relative molecular mass of the hydrogenated compounds, the valence ratio of potassium hydroxide to molybdenum hydroxide and the compensation ratio of the chemical table and the heat shield.
If the duplicate determination results do not meet the following conditions, the duplicate determination results shall be repeated:
The actual VFA value is equal to or less than 0.1U unit. The difference is within 0.C1 unit. The difference is within 1% when the actual VFA value is greater than or equal to 0.10 unit. Test report
The test report shall include the following contents:
a) 4 standard codes!
b) The required information for identification of the product.
e) The determination results and their units:
The excess attenuation in each unit
e) Any operation not included in this standard is considered to be acceptable. 1: For centrifugal and high-concentrated oils, a-1. 22 mg/m6
Standard Technical Network
Standard Industry Information Software
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.