ISO 16152:2022

Overview

ISO 16152:2022 - Plastics - Determination of xylene‑soluble matter in polypropylene - specifies two validated methods to measure the mass fraction of polypropylene (homopolymer or copolymer) that is amorphous and therefore soluble in xylene at 25 °C. The standard includes a Method 1 (reference gravimetric method) and Method 2 (automated instrumental method) and replaces the 2005 edition with updated procedures, apparatus lists and an added automated technique.

Key topics and technical requirements

• Scope and principle
  • Quantifies the xylene‑soluble fraction (amorphous content) by dissolving polypropylene in xylene under reflux, cooling to 25 °C to allow crystallization of the insoluble fraction, then isolating and weighing the soluble residue (Method 1) or measuring it via an automated instrumental technique (Method 2).
• Apparatus and sensitivity
  • Typical equipment: 400 mm reflux condenser, 500 ml flasks, thermostatted water bath (25 °C ± 0.5 °C), magnetic stirrer, vacuum oven, analytical balance (min. 0.1 mg sensitivity; 0.01 mg preferred).
• Reagents and solvent preparation
  • Reagent‑grade o‑xylene (reference solvent) and p‑xylene specifications are given (GC assay ≥ 98 %, low ethylbenzene, low residue). Antioxidants (e.g., BHT) recommended for stabilization; a typical stabilizer level ≈ 0.02 g·L‑1 and degassing by nitrogen are described.
• Sample preparation and test portions
  • Drying instructions (e.g., vacuum oven at 70 °C ± 5 °C,