Standard Guide for Measurement of Polyolefin Properties Using TD-NMR Relaxometry

Importancia y uso:

5.1 This guide is intended to assist users how to determine polymer properties in polyolefins related to their morphology (2) using TD-NMR Relaxometry, for example, Xylene Solubles (XS) content in polypropylene (PP).

5.2 The advantage of using TD-NMR Relaxometry lies in the fact that the method is rapid, non-destructive, cost effective, safe for the operator, environmentally friendly, and less dependent on operator consistency than traditional methods.

5.3 These polymer properties are measured for Quality Assurance (QA), Quality Control (QC) (7) and process control, for example, certificates of analysis (CoA) or optimization of the reaction process (6). These properties are key indicators of performance characteristics and are therefore important in compounding and manufacturing of plastic products.

5.3.1 This guide is applicable in a laboratory environment, continuous inspection as a quality control or as a research tool. It is also appropriate for use in commercial processes used to produce polyethylene and polypropylene.

5.4 TD-NMR Relaxometry can measure crystallinity content and relaxation rates directly (4), (5). Polyolefin properties used in industry that are correlated with crystallinity can be quantified. In these cases, a calibration is necessary.

5.5 As a secondary technique, results achieved by different TD-NMR Relaxometry systems, even from the same vendor, in different laboratories are not necessarily comparable and may result in biases. Therefore, the user is advised to perform measurement validation.

Subcomité:

D20.70

Volúmen:

08.03

Número ICS:

83.080.01 (Plastics in general)

Palabras clave:

density; NMR; NMR Relaxometry; polyolefin; polyethylene; polypropylene; Xylene Solubles content;