Comparison of Three NMR Methods for Measuring Crosslink Density of Rubbers

  • GAO Peng-fei ,
  • CHU Lin-lin ,
  • YANG Yi ,
  • JIANG Ji-feng ,
  • WANG Jia-chen ,
  • YAO Ye-feng ,
  • ZHOU Bing
Expand
  • 1. Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai 200062, China;
    2. Shanghai Niumag Electronic Technology Co., Ltd, Shanghai 200062, China;
    3. Double Coin Group Shanghai Tire Research Institute Co., Ltd, Shanghai 200237, China;
    4. School of Materials Science and Engineering, Tongji University, Shanghai 201804, China

Received date: 2017-04-05

  Revised date: 2017-10-29

  Online published: 2017-11-29

Abstract

NMR is a frequently used technique for measuring crosslink density of rubbers. In this work, three commonly used proton NMR methods for measuring crosslink density of rubbers[i.e., 1H double-quantum (DQ) NMR, 1H Hahn echo and 1H CPMG echo] were compared. Different approaches showed different results, and the origin of such discrepancy was discussed. The echo time dependence of the crosslink density measured with the CPMG echo method was studied. The ways to improve theCPMG echo-based measurements are discussed.

Cite this article

GAO Peng-fei , CHU Lin-lin , YANG Yi , JIANG Ji-feng , WANG Jia-chen , YAO Ye-feng , ZHOU Bing . Comparison of Three NMR Methods for Measuring Crosslink Density of Rubbers[J]. Chinese Journal of Magnetic Resonance, 2017 , 34(4) : 408 -420 . DOI: 10.11938/cjmr20172571

References

[1]WANG Z L.Crosslinking density of rubbers and the method of determination[J].World Rubber Industry,1998,25(4):41-46.王作龄.橡胶的交联密度与测定方法[J].世界橡胶工业,1998,25(4):41-46. [2]ZHU R P,ZOU B,YANG J.Effect of crosslinking density on dynamic performance of natural rubber[J].Special Purpose Rubber Products,2009,30(1):43-45.朱闰平,邹波,杨军.交联密度对天然橡胶动态性能的影响[J].特种橡胶制品,2009,30(1):43-45. [3]SCHLOGL S,TRUTSCHEL M L,CHASSÉ W,et al.Entanglement effects in elastomers:macroscopic vs microscopic properties[J].Macromolecules,2014,47(9):2759-2773. [4]HAVRÁNEK A,HEINRICH G.Experimental and theoretical analysis of viscoelastic behavior of different polymer networks[J].Acta Polym,1988,39(10):563-567. [5]VILGIS T A,HEINRICH G.The essential role of network topology in rubber elasticity[J].Angew Makromol Chem,2003,202(1):243-259. [6]VILGIS T A,HEINRICH G.New aspects in rubber elasticity:a challenge for theoretical physics and applied materials sciences[J].Kautschuk Und Gummi Kunststoffe,1992,45(12):1006-1013. [7]SCHIMMEL K H,HEINRICH G.The influence of the molecular weight distribution of network chains on the mechanical properties of polymer networks[J].Colloid Polym Sci,1991,269(10):1003-1012. [8]VILGIS T A,GERT H.Statics and dynamics of heterogeneous polymer networks[J].Macromol Theor Simul,1994,3(3):271-293. [9]MULLINS L.Determination of degree of crosslinking in natural rubber vulcanization.Part I[J].J Polym Sci,1956,19(92):225-236. [10]GENNES P G D.Reptation of a polymer chain in the presence of fixed obstacles[J].J Chem Phys,1971,55(2):572-579. [11]KUHN W,PEREGI E,FEI Z,et al.Network dynamics of crosslinked polymers-crosslinking,filler and aging characterized by NMR parameters[J].Mater Res Soc Symp Proc,1991,33(1):217-223. [12]KUHN W,BARTH P,HAFNER S,et al.Material properties imaging of cross-linked polymers by NMR[J].Macromolecules,1994,27(20):5773-5779. [13]ZHAO F,BI W N,ZHANG P,et al.Influence of accelerators on structure of sulfur-cured natural rubber by nuclear magnetic resonance spectroscopy[J].China Synthetic Rubber Industry,2008,31(1):50-53.赵菲,毕薇娜,张萍,等.用核磁共振法研究促进剂对硫磺硫化天然橡胶结构的影响[J].合成橡胶工业,2008,31(1):50-53. [14]HAHN E L.Spin echoes[J].Phys Rev,1950,80:580-594. [15]ZHAO S Y,WANG Y Y,ZHANG R R.Low-field NMR studies on the structure and dynamics of nanocomposite hydrogels[J].Chinese J Magn Reson,2014,31(2):172-184.赵守远,王媛媛,张荣纯.低场固体NMR研究纳米复合凝胶结构与动力学[J].波谱学杂志,2014,31(2):172-184. [16]GAO Y,ZHANG R C,LV W F,et al.Critical effect of segmental dynamics in polybutadiene/clay nanocomposites characterized by solid state 1H NMR spectroscopy[J].J Phys Chem C,2014,118(10):5606-5614. [17]CARR H Y,PURCELL E M.Effect of diffusion on free precession in nuclear magnetic resonance experiments[J].Phys Rev,1954,94(3):630-638. [18]MEIBOOM S,GILL D.Modified spin-echo method for measuring nuclear relaxation times[J].Rev Sci Instrum,2004,29(8):688-691. [19]BAUM J,PINES A.NMR studies of clustering in solids[J].J Am Chem Soc,1986,108(24):7447-7454. [20]HEUERT U,KNÖRGEN M,MENGE H,et al.New aspects of transversal 1H-NMR relaxation in natural rubber vulcanization[J].Polym Bull,1996,37(4):489-496. [21]SIMON G,BIRNSTIEL A,SCHIMMEL K H.Network characterization of end-linked poly (dimethyl siloxane) by 1H NMR spin-spin relaxation[J].Polym Bull,1989,21(2):235-241. [22]FRY C G,LIND A C.Determination of crosslink density in thermoset polymers by use of solid-state proton NMR techniques[J].Macromolecules,1988,601(2):921-929. [23]FETTERS L J,LOHSE D J,RICHTER D,et al.Connection between polymer molecular weight,density,chain dimensions,and melt viscoelastic properties[J].Macromolecules,1994,27(17):4639-4647. [24]SAALWÄCHTER K,KLÜPPEL M,LUO H,et al.Chain order in filled SBR elastomers:a proton multiple-quantum NMR study[J].Appl Magn Reson,2004,27(3,4):401-417. [25]SAALWÄCHTER K,ZIEGLER P,SPYCKERELLE O,et al.1H multiple-quantum nuclear magnetic resonance investigations of molecular order distributions in poly (dimethyl siloxane) networks:Evidence for a linear mixing law in bimodal systems[J].J Chem Phys,2003,119(6):3468-3482. [26]SAALWÄCHTER K.1H multiple-quantum nuclear magnetic resonance investigations of molecular order in polymer networks.Ⅱ.Intensity decay and restricted slow dynamics[J].J Chem Phys,2004,120(1):454-64. [27]SAALWÄCHTER K,AND B H,LÓPEZMANCHADO M A.Chain order and cross-link density of elastomers as investigated by proton multiple-quantum NMR[J].Macromolecules,2005,38(38):9650-9660. [28]GRAF R,HEUER A,SPIESS H W.Chain-order effects in polymer melts probed by 1H double-quantum NMR spectroscopy[J].Phys Rev Lett,1998,80(26):5738-5741. [29]FLORY P J.,REHNER J.Statistical mechanics of cross-linked polymer networks Ⅱ Swelling[J].J Chem Phys,1943,11:521-526. [30]PATEL S K,MALONE S,COHEN C,et al.Elastic modulus and equilibrium swelling of poly (dimethyl siloxane) networks[J].Macromolecules,1992,25:5241-5251. [31]BREMNER T,RUDIN A.The effect of degassing on the measurement of transverse relaxation times in molten polymers[J].J Polym Sci Poly Phys,1996,34(11):1893-1902. [32]LITVINOV V M,RIES M E,BAUGHMAN T W,et al.Chain entanglements in polyethylene melts.Why is it studied again[J].Macromolecules,2013,46(2):541-547. [33]WHITTAKER A K,BREMNER T,ZELAYA F O.The effect of field inhomogeneous and molecular diffusion on the NMR transverse relaxation behavior of polymer melts[J].Polymer,1995,36(11):2159-2164.
Outlines

/