GB/T 12008.6-2010 PDF English
US$185.00 · In stock · Download in 9 secondsGB/T 12008.6-2010: Plastics -- Polyether polyols -- Part 6: Determination of degree of unsaturation Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedureStatus: Valid GB/T 12008.6: Evolution and historical versions
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivery | Name of Chinese Standard | Status |
| GB/T 12008.6-2010 | English | 185 |
Add to Cart
|
0-9 seconds. Auto-delivery
|
Plastics -- Polyether polyols -- Part 6: Determination of degree of unsaturation
| Valid |
| GB/T 12008.6-1989 | English | 239 |
Add to Cart
|
2 days
|
Polyether polyols--Determination of water content
| Obsolete |
Excerpted PDFs (Download full copy in 9 seconds upon purchase)PDF Preview: GB/T 12008.6-2010
GB/T 12008.6-2010: Plastics -- Polyether polyols -- Part 6: Determination of degree of unsaturation---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT12008.6-2010
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 83.080; 83.080.01
G 31
Replacing GB/T 12008.7-1992
Plastics - Polyether Polyols - Part 6: Determination of
Degree of Unsaturation
ISSUED ON: SEPTEMBER 26, 2010
IMPLEMENTED ON: AUGUST 1, 2011
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 5
4 Principle ... 5
5 Application ... 6
6 Interference ... 6
7 Method A---High-volume Reagent Method ... 6
8 Method B---Low-volume Reagent Method ... 8
9 Test Report ... 11
Appendix A (informative) Precision of Low-volume Method ... 12
Bibliography ... 14
Plastics - Polyether Polyols - Part 6: Determination of
Degree of Unsaturation
1 Scope
This Part of GB/T 12008 specifies the method for the determination of degree of unsaturation
of polyether polyols.
This Part is applicable to the determination of degree of unsaturation of polyether polyols. It
can be used for quality control and scientific research, but it does not apply to compounds, in
which, the unsaturated part of the molecule is connected to the carbonyl group, carboxyl group
or nitrile group.
This Part does not address any safety issues associated with its use. Prior to use, it is the user’s
responsibility to establish appropriate safety and health measures and determine the scope of
application of regulatory limitations.
2 Normative References
The clauses in the following documents become clauses of this Part through reference in this
Part of GB/T 12008. In terms of references with a specified date, all subsequent amendments
(excluding corrigenda) or revisions do not apply to this Part. However, parties to an agreement
based on this Part are encouraged to explore the possibility of adopting the latest versions of
these documents. In terms of references without a specified date, the latest version applies to
this Standard.
GB/T 2035-2008 Terms and Definitions for Plastics (ISO 472:1999, IDT)
GB/T 12008.5-2010 Plastics - Polyether Polyols - Part 5: Determination of Acidity as Acid
Number
3 Terms and Definitions
The terms and definitions established in GB/T 2035-2008 and the following apply to this Part.
3.1 unsaturation
The content of carbon-carbon double bonds in a compound or polymer.
4 Principle
The carbon-carbon unsaturated compounds in the specimen react with mercuric acetate-
methanol in methanol solution and generate mercuric acetate methoxy compounds and acetic
acid. Use a standard titration solution of potassium hydroxide in alcohol to titrate the generated
acetic acid, thereby, calculating the degree of unsaturation. Due to the formation of insoluble
mercuric oxide, in the presence of excess mercuric acetate, the acid cannot be titrated; add
sodium bromide to convert the excess mercuric acetate into mercuric bromide, which does not
affect the determination. This method is based on acid form titration, with phenolphthalein as
the indicator, and if the sample is not neutral, it shall be appropriately adjusted. During the test,
attention shall be paid to eliminate carbon dioxide, as it will be titrated as an acid and lead to
erroneous results.
There are two methods for the determination of the degree of unsaturation of polyether polyols:
Method A: high-volume reagent method---use 25 mL of 0.1 mol/L mercuric acetate-methanol
solution and 15 g or more sample, and the indicator to determine the end point of color
development. It is recommended for the determination of polyols with a low degree of
unsaturation (lower than 0.01 mol/kg).
Method B: low-volume reagent method---use 2 mL of 0.05 mol/L mercuric acetate-methanol
solution and 1 g or less sample, and potentiometrically titrate to indicate the end point.
5 Application
Due to the side reaction of unsaturated compounds in propylene oxide, a small amount of
monohydroxy polymers will be generated. These unsaturated polymers reduce the degree of
functionality and molecular weight, and the overall molecular weight distribution of the
polymers becomes broadened.
6 Interference
Since the reaction products of compounds, in which, the unsaturated part of the molecule is
connected to the carbonyl group, carboxyl group or nitrile group, are easily hydrolyzed to
generate alkaline mercury salts, the system shall be anhydrous. Although the presence of low-
concentration acetone makes the end point less obvious, the effect is not significant. The sample
shall be free of inorganic salts, especially halides, because even small amounts of salts can
render the reaction of mercuric acetate with unsaturated compounds ineffective.
7 Method A---High-volume Reagent Method
7.1 Instruments
7.1.1 Pipette: 25 mL.
7.1.2 Conical flask: 250 mL, with a glass stopper.
D---the volume of 0.05 mol/L potassium hydroxide-ethanol standard titration solution
consumed by titration of the test portion, expressed in (mL);
E---the volume of 0.05 mol/L potassium hydroxide-ethanol standard titration solution
consumed by titration of the blank, expressed in (mL);
N---the concentration of potassium hydroxide-ethanol standard titration solution, expressed in
(mol/L);
C---the acidity value of the specimen (calculated as the amount of KOH consumed), expressed
in (mg/g);
W---the mass of the test portion, expressed in (g);
56.1---the numerical value of the molar mass of potassium hydroxide, expressed in (g/mol).
7.5 Precision
The difference between parallel results obtained by the same person shall not exceed 0.002.
8 Method B---Low-volume Reagent Method
8.1 Instruments
8.1.1 Pipette: 2 mL.
8.1.2 Automatic titrator: it can determine the acid form end point and is equipped with a 5 mL
burette.
8.1.3 Complex, glass and pH electrode for use with the automatic titrator.
8.1.4 Analytical balance: accurate to 0.1 mg.
8.1.5 Titration container: with a capacity of 100 mL.
8.2 Reagents
Unless otherwise stated, only analytically pure reagents are used.
8.2.1 Methanol.
8.2.2 Mercuric acetate-methanol solution: c = 0.05 mol/L.
Dissolve 16 g of mercuric acetate [Hg(C2H3O2)2] in 1 L of methanol solution, add a sufficient
amount of glacial acetic acid, so that 2 mL of the reagent blank consumes 0.5 mL ~ 1 mL of
0.05 mol/L potassium hydroxide-methanol standard titration solution. Usually, it is necessary
to add a few drops of glacial acetic acid. The solution needs to be weekly prepared and filtered
before use.
8.2.3 Potassium hydroxide-methanol standard titration solution: c (KOH) = 0.05 mol/L.
Dissolve potassium hydroxide in methanol to prepare a 0.05 mol/L solution. Use standard
potassium hydrogen phthalate for calibration.
8.2.4 Hydrochloric acid-methanol standard titration solution: c (HCl) = 0.05 mol/L.
Add concentrated hydrochloric acid to methanol solution to prepare a 0.05 mol/L solution. This
will introduce less than 0.5% water into the reagent. Use 0.05 mol/L potassium hydroxide-
methanol standard titration solution for calibration.
8.2.5 Sodium bromide.
8.3 Steps
8.3.1 If it is known that the degree of unsaturation of the specimen is not greater than 0.033
mol/kg, weigh approximately 1 g (accurate to 0.1 mg) of the test portion. If the degree of
unsaturation of the specimen is unknown, use 1 g of specimen to determine the approximate
value of its degree of unsaturation, and divide 0.033 by the approximate value of the degree of
unsaturation of the sample to calculate the required mass of the test portion, expressed in (g).
8.3.2 Add 2 mL of mercuric acetate-methanol solution (8.2.2) and shake it, until the test portion
is completely dissolved. Use a watch glass to cover it and let it stand for at least 30 minutes.
Add 50 mL of methanol (8.2.1), then, add 0.25 g of sodium bromide (8.2.5).
8.3.3 On the automatic titrator (8.1.2), use 0.05 mol/L potassium hydroxide-methanol standard
titration solution (8.2.3) to titrate it to the end point.
8.3.4 Without adding any sample, in accordance with the same steps, carry out a blank test.
8.3.5 Without adding mercuric acetate, in accordance with the same steps, prepare the sample,
and determine the acidity or alkalinity of the polyol to correct the result. Use 0.05 mol/L
potassium hydroxide-methanol standard titration solution to titrate it to the potential end point.
If the solution to be determined has passed the acidity end point, use 0.05 mol/L hydrochloric
acid-methanol standard titration solution (8.2.4) and repeat this step to determine the alkalinity.
8.4 Result Calculation and Expression
8.4.1 The acidity A of the specimen, expressed in (mol/kg), shall be calculated in accordance
with Formula (2):
Where,
VA---the volume of 0.05 mol/L potassium hydroxide-methanol standard titration solution
consumed by neutralization of the test portion, expressed in (mL);
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
Tips & Frequently Asked QuestionsQuestion 1: How long will the true-PDF of English version of GB/T 12008.6-2010 be delivered?Answer: The full copy PDF of English version of GB/T 12008.6-2010 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice. Question 2: Can I share the purchased PDF of GB/T 12008.6-2010_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 12008.6-2010_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 12008.6-2010 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds. Question 5: Should I purchase the latest version GB/T 12008.6-2010?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 12008.6-2010 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. How to buy and download a true PDF of English version of GB/T 12008.6-2010?A step-by-step guide to download PDF of GB/T 12008.6-2010_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).
Step 2: Search keyword "GB/T 12008.6-2010".
Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart.
Step 4: Select payment option (Via payment agents Stripe or PayPal).
Step 5: Customize Tax Invoice -- Fill up your email etc.
Step 6: Click "Checkout".
Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively.
Step 8: Optional -- Go to download PDF.
Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice.
See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9
|