结晶聚苯乙烯中油含量检测方案(核磁共振)

Mineral Oil is added to Crystal Polystyrene to increase itsflexibility. Precise control of the amount of mineral oil used isnecessary to ensure the correct performance properties areobtained reproducibly. NMR can provide a rapid and effectivemeans of monitoring the mineral oil content in crystalpolystyrene. Method NMR has a number of advantages over other techniques： ● NMR is very stable over the long term and rarely needscalibration adjustment. ● The measurement time is short (typically two seconds) ● The NMR technique is non-destructive， so the same samplemay be measured several times before being analysed byother techniques. ● NMR is insensitive to air voids between polystyrene granules. ● Measurement precision is good compared to wet chemicalmethods. ●NMR does not require the use of hazardous solvents. ● Both weighing and non-weighing methods are availablefor this application Calibration and Results Five samples of crystal polystyrene were selected for theanalysis of mineral oil content. Each sample was weighed intoa tared 26mm glass tube and preconditioned for an hour at105℃， before being placed in an MQC+ for analysis. The graph in Figure 1 illustrates the calibration of the NMRmeasurements against mineral oil contents determined bya reference method for these samples. The quality of thecalibration exhibited in Figure 1 is excellent， as indicated bythe correlation coefficient of 1 and the standard deviationof 0.07. Application Note 9 Figure 1： Calibration of NMR data and reference values for oil content.Correlation Coefficient： r=1； Standard Deviation= 0.07. Recommended Instrument The MQC+ with a 0.55 Tesla (23 MHz hydrogen resonance)magnet， fitted with a 26mm diameter (14ml sample) probeis a suitable instrument for this application. The Oil in CrystalPolystyrene package consists of： ● MQC+ with a built-in computer operating Microsoft@Windows@ 10 (no separate PC is required). ● MultiQuant software including RI Calibration， RI Analysis，and the EasyCal 'Oil in Crystal Polystyrene'application. D 26mm glass tubes. ● User Manual. ●'Oil in CrystalPolystyrene'method sheet. The Business of Science" In addition to this package you will also require： ● A dry heater and aluminium block with 26mm holes forsample conditioning at 105C. ● A precision balance. The instrument offers multiple advantages over otherson the market： ● High signal sensitivity. DsSmall benchtop footprint. ●Low maintenance. ● Recyclable sample tubes， lowering consumable costs. ● Minimal sample preparation. Note： Other instruments/packages are available for the analysis of larger orsmaller sample quantities. Please contact Oxford Instruments for further details visit www.oxford-instruments.com/mqc for more information or email： magres@oxinst.com ( This publication is the copyright of Oxford Instruments and provides outline informatio n o nly which (un l ess a gre ed by the company in w ri ti ng)may not be used， applied or reproduced for any purpose or form part of any order or c o n trac t or be r eg a r ded a s a r e p r e sentati o n rel ati n gto the products or services concerned. Oxford Instruments’ policy is one of continu e d i mp r o ve me n t. The c o mpa n y re s e r v es t he righ t t o a lt er ，without notice， the specification， design or conditions of supply of any pro d uct or ser v i c e . Ox f o r d I nstr u men ts ac k now le d ges all t ra d emarksand registrations. @ Oxford Instruments plc， 2018. All rights reserved. Par t no.F F -0 3 -18 ) The Business of Science" 聚苯乙烯是如今最常用的聚合物之一。纯聚苯乙烯具有高度结晶性和刚性，因此很脆。将聚合物与矿物油混合可以增加材料柔性并降低其脆性。为获得可再现性能属性，准确控制聚合物中矿物油含量十分必要。 牛津仪器的 MQC+ 台式核磁共振分析仪提供了一种测定结晶聚苯乙烯矿物油含量的快速、简单和准确的方法。