GB/T 8299-2008Natural rubber latex concentrate -- Determination of dry rubber content (English PDF)

Foreword

This standard is identical with ISO 126:2005 "Determination of dry rubber content of natural rubber latex concentrate" (in English).

For ease of use, the editorial changes made the following standard.

--- "This International Standard" be replaced by "this standard";

--- Delete foreword international standards;

--- References GB/T 8290, GB/T 8298 in Chapter 2, normative references, these two standards and ISO 126:2005's There is no technical difference in the respective sections.

This standard replaces GB/T 8299-2001 "Natural rubber latex concentrate - Determination of dry rubber content." the main difference compared with the standard GB/T 8299-2001 as follows.

--- Deleted the ISO foreword;

--- In Chapter 2 normative references added GB/T 14838 "Rubber and rubber products precision test method standards determine";

--- The amount of 8.4 by the acetic acid solution 75mL ± 3mL to 35mL ± 3mL;

--- The drying temperature in the film by a 8.7 ± 5 °C 70 °C ± 2 °C to 70 °C;

--- Increased Chapter 10, "precision instructions." the standard proposed by China Petroleum and Chemical Industry Association.

This standard by the National Standardization Technical Committee rubber products natural rubber and rubber Technical Committee.

This standard was drafted. Chinese Tropical Institute of Agro Agricultural Sciences, Ministry of Agriculture, Food Quality Supervision and Testing Center (Cham Jiang).

1 Scope

This standard specifies the method for determination of dry rubber content of concentrated natural rubber latex.

This standard does not necessarily apply to natural latex of Hevea brasiliensis latex outside, with latex, vulcanized latex emulsion or latex. Does not apply in synthetic latex.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 8290 Natural rubber latex concentrate sampling (GB/T 8290-1987, eqv ISO 123. 1985) GB/T 8298 Natural rubber latex concentrate - Determination of total solids content (GB/T 8298-2008, ISO 124:1997, MOD) ISO/T R9272 Rubber and rubber products - Determination of precision for test method standards (ISO/T R9272.2004, Rubberand rubberproducts-Determinationofprecisionfortestmethodstandards)

3 Terms and Definitions

The following terms and definitions apply to this standard.

Ammonia and/or other preservatives, processed and concentrated natural rubber latex.

Principle 4

The concentrated latex sample was diluted to a total solids content of the mass fraction of 20%, and acidified with acetic acid. The coagulated rubber is then pressed into thin Sheet, at 70 °C ± 5 °C dried.

5 Reagents

Unless otherwise indicated in the analysis using only recognized as analytical grade reagents and distilled water, deionized water or equivalent purity water.

5.1 acetic acid solution, 20g of glacial acetic acid diluted with water to 1L, save for ammonia concentrated latex.

Acetic acid solution 5.2 propylene glycol, propylene glycol 50g/L of potassium hydroxide to concentrated latex preserved.

Add 50g in 500mL of glacial acetic acid in propylene glycol and diluted with water to 1L.

5.3 ethanol, volume fraction of 95%.

6 Instruments

6.1 conventional laboratory instruments and glass dish or porcelain dish diameter of about 100mm, depth of about 50mm.

Note. does not apply to aluminum dish containing potassium hydroxide concentrated latex.

6.2 balance, accuracy of 1mg.

6.3 Oven temperature was kept 70 °C ± 5 °C.

GB/T 8299-2008/ISO 126:2005