GB/T 18396-2025Rubber latex - Determination of surface tension (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document replaces GB/T 18396-2008 "Natural rubber latex ring method for the determination of surface tension". Compared with GB/T 18396-2008, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) The scope was changed, the ring method was changed to method A "platinum ring method", B "platinum plate method" was added, and the applicable limits were changed (See Chapter 1, Chapter 1 of the 2008 edition);

b) Added the "Principle" of Method B (see 4.2) and the instrument "Surface Tensiometer (Wilhelmy type)" (see 6.2);

c) Added the instrument "Bunsen burner or alcohol burner" (see 6.5);

d) When the sample viscosity is greater than.200 mPa·s, the determination is based on SH/T 1152 (see 8.1.3.1);

e) Added the test steps (see 8.2) and result expression (see 9.2) of Method B;

f) The basis for determining precision has been changed (see Chapter 10, Chapter 9 of the 2008 edition);

g) The test report has been changed (see Chapter 11, Chapter 10 of the 2008 edition).

This document modifies ISO 1409:2020 "Surface tension of plastic/rubber polymer dispersions, natural latex and synthetic latex".

Determination.

This document has the following structural adjustments compared to ISO 1409:2020.

--- Divide 8.1.4 into "8.1.4.1 Manual surface tension meter determination" and "8.1.4.2 Automatic surface tension meter determination";

--- Added 8.2.4.4 "Automatic surface tension measurement" and added the automatic surface tension measurement method in 8.2.4.3 of ISO 1409:2020.

The content measured by the instrument is moved to this article;

---Appendix A and Appendix B correspond to Appendix B and Appendix A of ISO 1409:2020 respectively.

The technical differences between this document and ISO 1409:2020 and their reasons are as follows.

--- Changed the scope (see Chapter 1, Chapter 1 of ISO 1409:2020), deleted the application to polymer dispersions and method A as the first Select methods to suit my country's technical conditions;

--- Delete the first paragraph of the principle of method A (see 4.1 of ISO 1409:2020) because it does not explain the principle of the test method;

--- ISO 3696 (see 5.1) was replaced by the normative reference GB/T 6682 to adapt to my country's technical conditions;

--- ISO 123 (see Chapter 7) has been replaced by the normative reference GB/T 8290 to adapt to the provisions of my country on latex sampling;

--- ISO 124 (see 8.1.3.1) was replaced by the normative reference GB/T 8298 to adapt to the determination of total solid content of latex in my country provisions;

--- ISO 705 (see 8.1.3.1) has been replaced by the normative reference GB/T 17821 to adapt to the Chinese requirements for latex density determination Regulation;

--- The normative references NY/T 1037 and SH/T 1152 replaced ISO 1652 (see 8.1.3.1) to adapt to my country's natural Provisions for the determination of apparent viscosity of latex and synthetic latex;

--- ISO 2555 and ISO 3219 (see 8.1.3.1 of ISO 1409:2020) have been deleted as they are not applicable to natural rubber latex and synthetic Determination of apparent viscosity of latex;

--- Added provisions for determining the maximum measurement time (see Table 1) to facilitate the use of this document.

The following editorial changes were made to this document.

--- In order to coordinate with the existing standards, the name of the document is changed to "Determination of Surface Tension of Latex";

--- Added "Warning";

--- Change the explanatory description about the effect of instrument contamination on test results to "Note" (see 8.1.1);

--- Added a note that more reliable results can be obtained by using an automatic surface tension meter (see 8.1.4.2 and 8.2.4.4);

--- Deleted the footnote on latex abbreviations (see Table 1 of ISO 1409:2020);

--- Changed the precision of method A (see Appendix B).

1 Scope

This document describes two methods for determining the surface tension of natural and synthetic latex.

---Method A. Platinum ring method (DuNoüy ring method);

---Method B. Platinum plate method (Wilhelmy plate method).

Method A is applicable to natural latex and synthetic latex with a viscosity of less than.200 mPa·s.

Method B is applicable to natural latex and synthetic latex that do not contain cationic surfactants.

Method A and Method B are also applicable to pre-vulcanized latex and compounded latex.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

GB/T 6682 Specifications and test methods for water used in analytical laboratories (GB/T 6682-2008, ISO 3696:1987, MOD) GB/T 8290 Latex Sampling (GB/T 8290-2021, ISO 123:2001, MOD) GB/T 8298 Determination of total solid content of latex (GB/T 8298-2017, ISO 124:2014, MOD) GB/T 17821 Determination of density of latex at 5°C to 40°C (GB/T 17821-2008, ISO 705:1994, IDT) NY/T 1037 Determination of apparent viscosity of natural rubber latex - Rotational viscometer method (NY/T 1037-2016, ISO 1652.

2011,MOD)

SH/T 1152 Determination of apparent viscosity of synthetic rubber latex (SH/T 1152-2014, ISO 1652:2011, MOD)

3 Terms and definitions

There are no terms or definitions that require definition in this document.

4 Principle