Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: ASTM D4889-21
• Năm ban hành / Publication date: 2021
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: Standard Test Methods for Polyurethane Raw Materials: Determination of Viscosity of Crude or Modified Isocyanates
• Chỉ số phân loại Quốc tế (ICS) / By field: 83.040.30 - Vật liệu phụ và phụ gia cho chất dẻo; 83.080.20 - Vật liệu dẻo nhiệt
• Số trang / Page: 5

Phạm vi áp dụng / Scope of standard

1.1 These test methods (A and B) determine the viscosity of crude or modified isocyanates. They are applicable to products derived from toluene diisocyanate, methylene di(phenylisocyanate), and polymeric (methylene phenylisocyanate) (see Note 1).

Note 1: Test method A includes a procedure for measuring dynamic viscosity using a rotational instrument. Test method B is a general procedure for kinematic viscosity of isocyanate.

1.2 The values stated in SI units are to be regarded as standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazards statement, see Warning at the end of 5.1.

Note 2: Test Method A is equivalent to ISO 3219, Test Method B is equivalent to ISO 3104.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.