Overview
ISO 15023-2:2019 - Plastics - Poly(vinyl alcohol) (PVAL) materials - Part 2: Determination of properties specifies standardized test methods for determining key properties of poly(vinyl alcohol) (PVAL). The standard applies to PVAL produced by hydrolysis of poly(vinyl acetate), whose composition contains vinyl alcohol and vinyl acetate units, with a degree of hydrolysis from 70 mol% to 100 mol%. In addition to the designatory properties given in ISO 15023-1 (degree of hydrolysis and viscosity), this part defines additional commonly used property determinations used for material specification and quality control.
Key topics and technical requirements
- Scope and applicability: Methods cover PVAL materials within the 70–100 mol% hydrolysis range and are intended for materials free of interfering additives unless separated by agreement.
- Properties and test conditions (Table 1): Includes volatile-matter content, sodium acetate content, ash (calculated as sodium oxide), degree of hydrolysis, viscosity of a 4% aqueous solution, particle size distribution, and pH of aqueous extracts.
- Highlighted test methods / annexes
- Annex A - Volatile-matter content: loss on drying at 105 °C for 3 hours (duplicate determinations).
- Annex B - Sodium acetate content: titration (HCl with methylene blue/methyl yellow indicator) or conductivity-based method (calibrated conductometer).
- Annex C - Ash calculation: conversion of sodium acetate content to ash (factor 0.378).
- Annex D - Degree of hydrolysis: titrimetric determination of residual acetate groups, reported in mol%.
- Annex E - Viscosity of a 4% aqueous solution: measured by rotational (Brookfield) or inclined-tube falling-ball viscometer at 20 °C.
- Reporting requirements: Test reports must reference ISO 15023-2:2019, identify the material, report means of duplicate tests and individual results, and include test dates.
Practical applications and users
ISO 15023-2:2019 is intended for:
- PVAL manufacturers for production control and material certification.
- Quality-control and analytical laboratories performing routine property testing.
- Procurement teams and specification writers who need standardized property definitions for purchasing and material specifications.
- R&D and product development groups requiring reproducible property measurement methods.
Using these standardized test methods ensures reproducible, traceable results for degree of hydrolysis, viscosity, sodium acetate/ash, and other critical PVAL properties - supporting consistent product quality and reliable material data.
Related standards
Keywords: ISO 15023-2:2019, poly(vinyl alcohol), PVAL testing, degree of hydrolysis, viscosity, sodium acetate, volatile-matter content, ash calculation, materials specification.
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