GB/T 46231.1-2025Plastics - General test method for polyurethane raw materials - Part 1: Determination of hydroxyl number of polyols by NIR spectroscopy (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document is Part 1 of GB/T 46231, "General Test Methods for Polyurethane Raw Materials in Plastics". GB/T 46231 has been published.

The following parts were included.

---Part 1: Determination of hydroxyl value of polyols by near-infrared spectroscopy this document is modified to adopt ISO 15063:2011 "Determination of hydroxyl value of polyols by near-infrared spectroscopy for polyurethane production".

Compared with ISO 15063:2011, this document has undergone the following structural adjustments.

---Added versions 3.2, 3.3, and 3.5;

---3.4 corresponds to 3.2 in ISO 15063:2011;

---Appendix A corresponds to Appendix B in ISO 15063:2011;

---Appendix B corresponds to Appendix C in ISO 15063:2011;

---Appendix C corresponds to Appendix D in ISO 15063:2011;

---Appendix D corresponds to Appendix E in ISO 15063:2011;

---Appendix E corresponds to Appendix F in ISO 15063:2011;

---Appendix F corresponds to Appendix G in ISO 15063:2011;

---Appendix G corresponds to Appendix H in ISO 15063:2011;

---Appendix H corresponds to Appendix I in ISO 15063:2011;

---Appendix I corresponds to Appendix A in ISO 15063:2011;

---Appendix J has been added.

The technical differences between this document and ISO 15063:2011, and the reasons therefor, are as follows.

---Added terms and definitions for "hydroxyl value reference value," "hydroxyl value prediction value," and "boxcar distribution" (see 3.2, 3.3, and 3.5) to...

Regarding the understanding of the relevant content in the text;

---ISO 14900 has been replaced with the normatively referenced GB/T 12008.3-2009, and a reference value for the hydroxyl value of polyester polyols has been added.

The determination method is HG/T 2709-2022, and the determination method for the reference value of hydroxyl value of polymer polyols is GB/T 31062-2014.

To better suit the actual situation in China;

---ASTM E1655 has been replaced with the normatively referenced GB/T 29858-2013 to better reflect domestic practices;

---Added clear stipulations regarding the interval between collecting the spectral data of the calibration sample and determining the hydroxyl value of the calibration sample by chemical titration, from "as short as possible" to "the interval between collecting the spectral data of the calibration sample and determining the hydroxyl value of the calibration sample by chemical titration".

The phrase "within a given time" has been changed to "interval not exceeding 24 hours" [see 6.2.c)] for ease of practical operation;

---The absorbance range has been expanded, changing "1.0~1.5" to "not greater than 1.5" (see 6.3.2) to better reflect the actual situation in China;

---When the hydroxyl value (calculated as KOH) is greater than 100 mg/g, the result should be retained to the nearest integer; when the hydroxyl value (calculated as KOH) is less than 100 mg/g, the result should be retained to the nearest integer.

The rule of "retaining results to one decimal place" is now uniformly changed to retaining all results to one decimal place [see 12.c)], in order to maintain data accuracy.

Consistency of accuracy;

---Change "informative" in Appendix D to "normative" to clarify the requirements for selecting calibration samples.

The following editorial changes have been made to this document.

---In order to conform to the national standard system optimization and construction plan, the standard name has been changed to "General Test Methods for Plastic Polyurethane Raw Materials".

Part 1: Determination of Hydroxyl Value of Polyols by Near-Infrared Spectroscopy;

---The prompt mentioning the informative appendix in section 4.1 has been removed;

---b in 7.2 has been removed);

---Added chapter headings to Appendix A, and deleted A.5;

---Added a note to Appendix E.4.2;

---Appendix I replaces the foreign validation data in Annex A of ISO 15063:2011 with domestic validation data;

---Appendix J (Informative) "Reproducibility Precision" has been added to supplement the recommendation of repeatability precision for this method.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China Petroleum and Chemical Industry Federation.

This document is under the jurisdiction of the National Technical Committee on Plastics Standardization (SAC/TC15).

Introduction

GB/T 46231, "General Test Methods for Raw Materials Used in Polyurethane Production," is a series of standards concerning general test methods for raw materials used in polyurethane production.

The standard is proposed to consist of eight parts.

---Part 1: Near-Infrared Spectroscopy for Determination of Hydroxyl Values in Polyols. The purpose is to describe a near-infrared spectroscopy method for determining the hydroxyl value of polyols used in polyurethane production.

Methods for determining the hydroxyl value of various polyol raw materials, such as ester polyols, polyether polyols, polycaprolactone polyols, and polycarbonate polyols.

---Part 2: Determination of Residual Acrylonitrile and Styrene Monomer Content in Polymer Polyols by Gas Chromatography. The aim is to describe the gas chromatography method.

A method for determining the content of acrylonitrile and styrene monomers in polymer polyols used in polyurethane production by phase chromatography.

---Part 3: Determination of Water Mass Fraction. The purpose is to describe a method for determining the water mass fraction in raw materials used in polyurethane production.

---Part 4: Viscosity Determination. The purpose is to describe a method for determining the viscosity of raw materials used in polyurethane production.

---Part 5: Density Measurement with a Density Meter. The purpose is to describe a method for determining the density of raw materials used in polyurethane production using a density meter.

---Part 6: Determination of Isocyanate Group Content. The purpose is to describe the determination of isocyanate and prepolymer content in raw materials used in polyurethane production.

Methods for determining the isocyanate group content in materials.

---Part 7: Determination of Total Amine Value of Polyols. The purpose is to describe the determination of total amine value of amine polyols, polyether polyols, and polyols used in polyurethane production.

A method for determining the alkalinity (total amine value) of polyether polyol mixtures.

---Part 8: Determination of the Foaming Reaction Characteristics of the Pre-mixed Solution. The purpose is to describe and determine the foaming reaction characteristics of pre-mixed solutions used in polyurethane production.

method.

General Test Methods for Polyurethane Raw Materials Part 1: Determination of Hydroxyl Value of Polyols by Near-Infrared Spectroscopy Warning. Personnel using this document should be familiar with standard laboratory procedures. This document does not address safety issues related to its use.

Those in charge have a responsibility to establish appropriate safety and health measures and ensure that they comply with relevant national regulations.

1 Scope

This document describes a method for determining the hydroxyl value of polyols using near-infrared spectroscopy. It provides relevant definitions and modeling techniques, establishing the necessary framework.

The procedure for selecting calibration samples, collecting and processing data during the modeling process was established, and criteria for the establishment, evaluation, and validation of near-infrared models were also established.

Procedures for sample processing, data acquisition, and model evaluation.

This document applies to the research, quality control, specific testing, and process control of polyols used in polyurethane production.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 12008.3-2009 Determination of hydroxyl value of polyether polyols in plastics (GB/T 12008.3-2009, ISO 14900:2001) NEQ) GB/T 29858-2013 General Rules for Quantitative Analysis of Molecular Spectroscopy with Multivariate Correction GB/T 31062-2014 Polymer Polyols HG/T 2709-2022 Determination of hydroxyl value of polyester polyols used in the production of polyurethane

3 Terms and Definitions

The following terms and definitions apply to this document.

hydroxyl number (OH)