BS ISO 24076:2021 pdf free.Plastics -Polypropylene (PP) —Determinationof isotactic index by low-resolution nuclear magnetic resonance spectrometry.
BS ISO 24076 This document specifies a relative method for the determination of polypropylene (PP) isotactic indexby low-resolution pulsed nuclear magnetic resonance spectroscopy (LR-NMR).
This method enables the identification and coding of types H propylene (PP-H) plastics according toISO 19069-1.
This method is suitable for base polymers and is not applicable for mixtures.
NOTE The direct method for the determination of polypropylene isotactic index is specified in IS0 9113.
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO 9113,Plastics — Polypropylene 〔PP) and propylene-copolymer thermoplastics — Determination ofisotactic index.
For the purposes of this document, the following terms and definitions apply.
ISO and lEC maintain terminological databases for use in standardization at the following addresses:-ISO online browsing platform: available at https://www.iso.org/obp
IEC Electropedia: available at http:.//www.electropedia.org/
isotactic indexll percentage mass fraction of unextractable matter content in polypropylene, which cannot be extractedfrom polypropylene by boiling n-heptane.
The sample is placed in LR-NMR.After electromagnetic equilibration in the static magnetic field ofthe NMR spectrometer and application of a 90° radio frequency pulse, the magnetization decay signalcurve from the protons of the sample is recorded.The signal of the un-extractable matter in the sampledrops much faster than that of extractable matter. In the signal curve, initial signal corresponds tothe whole sample including the un-extractable and the extractable matter, and later slower droppingsignal corresponds to the extractable matter in the sample.So, the magnetization decay signal and theisotactic index of the sample are related.The isotactic index is either calculated from the ratio between the magnetization decay signal of theun-extractable part and the entire sample detected by a ratio probe(method A ratio method).BS ISO 24076 pdf download.