ASTM D6342-22 PDF
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St ASTM D6342-22
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Ст ASTM D6342-22
Original standard ASTM D6342-22 in PDF full version. Additional info + preview on request
Full title and description
Standard Practice for Polyurethane Raw Materials: Determining Hydroxyl Number of Polyols by Near Infrared (NIR) Spectroscopy (ASTM D6342-22). This practice specifies procedures for developing and using near‑infrared spectroscopic calibrations to determine the hydroxyl number of polyols used in polyurethane applications, including sample selection, instrument requirements, calibration development, validation, and routine analysis considerations.
Abstract
ASTM D6342-22 describes a practice for measuring the hydroxyl number of polyols by near‑infrared (NIR) spectroscopy. It covers definitions and terminology, guidance for selecting representative samples, data collection and pretreatment, chemometric calibration approaches (multivariate regression such as PCR/PLS), criteria for evaluating and validating calibration models, recommended handling and instrumental requirements, and limitations on applicability and transferability of calibrations.
General information
- Status: Active standard (current edition).
- Publication date: Current edition approved July 1, 2022; published July 2022 (designation D6342-22).
- Publisher: ASTM International.
- ICS / categories: 83.080.10 (Thermosetting materials — polyurethanes / polyols).
- Edition / version: D6342-22 (2022).
- Number of pages: 9 pages.
Scope
This standard covers a practice for the determination of hydroxyl numbers of polyols using NIR spectroscopy. It describes calibration-development procedures, sample selection, data-collection and preprocessing methods, validation criteria for NIR models, and recommended sample handling. The practice requires the NIR instrument to be installed in accordance with the manufacturer's specifications and notes that results are valid only within the calibrated composition and hydroxyl‑number ranges. The standard is written using SI units and is equivalent to ISO 15063.
Key topics and requirements
- Selection of representative calibration and validation samples that span expected chemical compositions and hydroxyl‑number ranges.
- Instrument requirements and installation—follow manufacturer specifications; instrument-to-instrument differences affect calibration transfer.
- Data collection procedures and sample handling to ensure reproducible spectra.
- Preprocessing and chemometric methods (e.g., PCR, PLS) for building multivariate calibration models.
- Model evaluation and validation criteria, including statistical performance metrics and outlier detection procedures.
- Limitations and applicability: calibrations are generally instrument‑ and composition‑specific; extrapolation beyond calibration ranges increases error.
- Guidance on calibration transfer, periodic verification, and factors affecting spectral response (temperature, additives, water, catalysts).
Typical use and users
This practice is used for research, quality control, specification testing, and process control in laboratories and production facilities that formulate or produce polyurethane ingredients. Typical users include polyol manufacturers, polyurethane formulators, analytical laboratories, quality engineers, instrument vendors, and R&D teams implementing NIR‑based rapid assays for hydroxyl‑number monitoring.
Related standards
Referenced and related standards include ASTM D4274 (test methods for determination of hydroxyl numbers of polyols), ASTM D883 (terminology relating to plastics), ASTM E131 (terminology relating to molecular spectroscopy), ASTM E168 (infrared quantitative analysis practices), and practices for comparing test methods and outlier detection (e.g., E1655 references and related chemometrics guidance). The practice is noted as equivalent to ISO 15063.
Keywords
hydroxyl number, polyol, polyurethane, NIR, near infrared spectroscopy, chemometrics, calibration, PLS, PCR, multivariate analysis, validation, calibration transfer, sample selection
FAQ
Q: What is this standard?
A: ASTM D6342-22 is a practice that provides procedures for determining the hydroxyl number of polyols using near‑infrared (NIR) spectroscopy, including how to develop, validate, and apply NIR calibrations for this property.
Q: What does it cover?
A: It covers definitions and terminology, sample selection, NIR data collection and preprocessing, chemometric calibration methods (multivariate regression), validation criteria, instrument installation considerations, limitations on applicability, and guidance on calibration transfer and routine use.
Q: Who typically uses it?
A: Polyol and polyurethane manufacturers, analytical and QC laboratories, R&D chemists and engineers, instrument vendors, and formulators who need rapid, validated methods for monitoring hydroxyl number in production or development environments.
Q: Is it current or superseded?
A: The current edition is D6342-22 (approved July 1, 2022) and is published as the active standard. It revises the prior edition (D6342-12, reapproved 2017).
Q: Is it part of a series?
A: D6342 belongs to ASTM Committee D20 (Plastics) procedures relating to polyurethane raw materials and is associated with other ASTM test methods and practices for polyols and infrared spectroscopic techniques; it is also declared equivalent to ISO 15063.
Q: What are the key keywords?
A: Key keywords are hydroxyl number, polyol, NIR, near‑infrared spectroscopy, chemometrics, calibration, PLS, PCR, multivariate analysis, and validation.