GB/T 15252-2014Rubber, compounded or vulcanized-Determination of sulfide sulfur content-Lodometric method (English PDF)

Foreword

This Standard replaces GB/T 15252-1994 "Rubber - Determination of sulfide sulfur content - Iodometric method." Compared with the standard GB/T 15252-1994, the main differences are as follows: - MODIFY the standard name; - ADD the foreword; - ADD the warning; - REVISE "cadmium acetate buffer solution" TO "zinc acetate buffer solution" (see 4.4,

4.2 of 1994 edition);. - MODIFY the description of the surfactant solution (see 4.5,

4.4 of 1994 edition); - ADD the description of "all-glass extraction device" (see 5.1); - ADD the description of "reaction between hydrogen sulphide and absorption device" (see 5.2); - REVISE "burette" TO "brown burette" (see 5.6,

5.3 of 1994 edition); - REVISE the reaction heating time from "30min ~ 40min" to "0min ~ 80min" (see 7.1.2, Chapter 6 of 1994 edition); - MODIFY the description of "Analysis steps" (see Chapter 7, Chapter 6 of 1994 edition); - ADD the content of the test report (see Chapter 9). This Standard was proposed by China Petroleum and Chemical Industry Association. This Standard shall be under the jurisdiction of the General Methods of Test Branch of the National Standardization Technical Committee on Rubber and Rubber Technology (SAC/TC 35/SC 2). Responsible drafting organization of this Standard. Xuzhou Xugong Tyres Co., Ltd. Participating drafting organizations of this Standard. Qingdao Yikesi New Material Co., Ltd., Guangzhou Institute of Synthetic Material Co., Ltd., Beijing Center for Physical and Chemical Analysis, Beijing Research and Design Institute of Rubber Industry. Main drafters of this Standard. Wei Bangfeng, Sheng Jie, Lin Qingju, Liu Xianlii, Tan Hongyang, Jia Li, Bi Penghao, Ding Xiaoying. Rubber, compounded or vulcanized - Determination of sulfide sulfur content - Lodometric method Warning. Personnel who use this Standard shall have experience of regular laboratory work. This Standard does not point out all possible safety issues; users have the responsibility to take appropriate safety and health measures, and to ensure that it complies with the conditions specified in relevant national regulations.

1 Scope

GB/T 15252-2014 is the Chinese national standard on rubber, compounded or vulcanized-determination of sulfide sulfur content-lodometric method, in the field of rubber and plastic industries. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 22 December 2014 by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of China, and has been in force since 1 June 2015. Classification: ICS 83.060, CCS G40. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This Standard specifies the test methods for determination of sulfide sulfur content in compounded and vulcanized rubber by iodometric method. This Standard applies to compounded and vulcanized rubber of halogenated rubber, nitrile rubber and hydrocarbon rubber (including natural rubber).

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this document.

GB/T 601-2002 Chemical reagent - Preparations of standard volumetric solutions

GB/T 603-2002 Chemical reagent - Preparations of reagent solutions for use in test methods

GB/T 3516-2006 Rubber - Determination of solvent extract

GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods

GB/T 17783-1999 Rubber, vulcanized - Preparation of samples and test pieces - Chemical tests

3 Principle

For rubbers extracted by acetone, use the mixture of hydrochloric acid and acetic acid 5.5 25mL pipette (grade A).

5.6 Brown burette.

6 Sampling and sample preparation

6.1 CUT the needed samples from vulcanized rubber specimen and finished rubber products according to the specifications in GB/T 17783-1999. For compounded rubber, it shall be made into compounded rubber slices by open mills with a roll pitch of not more than 0.5mm for 6 times at room temperature, and directly cut the test samples into small particles with a side length of less than 1mm. Vulcanized rubber is directly cut into small particles with a side length of less than 1mm.

6.2 WEIGH 0.5g ~ 2.0g of sample, accurate to 0.1mg.

6.3 WRAP the sample with filter paper, PLACE the sample in the the extraction unit (5.1) containing acetone (4.2) to extract for 6h ~ 8h.

6.4 TRANSFER the sample from Soxhlet extraction bottle to a weighing bottle; DRY in a 70°C oven for 15 min; PUT the dried sample into the extraction bottle (A).