Single-point imaging of vulcanized boundary in rubber

Prado, Pablo J.; Gasper, L.; Fink, Gerd; Blümich, Bernhard

doi:10.1007/bf03162109

Cited by 6 publications

(6 citation statements)

References 16 publications

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“…MRI techniques have been developed to handle the broad resonance lines and short T 2 associated with solids, facilitating the study of a variety of materials from polymers to ceramics. 14,[23][24][25][26][27][28][29][30][31][32][33][34][35][36] Single point imaging (SPI), also known as constant time imaging, developed by Emid and Creyghton, 37 is ideally suited to study materials with very short T 2 relaxation times.…”

Section: Relaxation Nuclear Magnetic Resonance Imaging (R-nmri) Of Dementioning

confidence: 99%

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.

Alam¹,

Cherry²,

Alam³

2004

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The production and aging of silicone materials remains an important issue in the weapons stockpile due to their utilization in a wide variety of components and systems within the stockpile. Changes in the physical characteristics of silicone materials due to long term desiccation has been identified as one of the major aging effects observed in silicone pad components. Here we report relaxation nuclear magnetic resonance imaging (R-NMRI) spectroscopy characterization of the silica-filled and unfilled polydimethylsiloxane (PDMS) and polydiphenylsiloxane (PDPS) copolymer (M9787) silicone pads within desiccating environments. These studies were directed at providing additional details about the heterogeneity of the desiccation process. Uniform NMR spin-spin relaxation time (T 2) images were observed across the pad thickness indicating that the drying process is approximately uniform, and that the desiccation of the M9787 silicone pad is not a H 2 O diffusion limited process. In a P 2 O 5 desiccation environment, significant reduction of T 2 was observed for the silica-filled and unfilled M9787 silicone pad for desiccation up to 225 days. A very small reduction in T 2 was observed for the unfilled copolymer between 225 and 487 days. The increase in relative stiffness with desiccation was found to be higher for the unfilled copolymer. These R-NMRI results are correlated to local changes in the modulus of the material.

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Section: Relaxation Nuclear Magnetic Resonance Imaging (R-nmri) Of Dementioning

confidence: 99%

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.

Alam¹,

Cherry²,

Alam³

2004

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“…Another approach that allows NMR imaging techniques to be utilized in materials is the incorporation of pulse sequences amenable to short T 2 values, avoiding the need for solvent swelling. These techniques include single-point imaging (SPI) and multipoint (MP) k -space mapping − and have permitted high-resolution images in a variety of solid materials to be obtained, including direct imaging of polymer samples. ,− …”

Section: Introductionmentioning

confidence: 99%

“…Parameter-related images are also known as material property images (MAP images) ,− T 2 maps of cross-link density in rubber and polyisobutylene, , multiple quantum-filtered and T 2 maps of strained elastomers and tendons, ,, T 2 maps of solvent permeation, , aging and boundary migration in natural rubbers, , and T 1 and T 2 maps of anisotropic molding effects in high-density polyethylene (HDPE) …”

Section: Introductionmentioning

confidence: 99%

“…These techniques include single-point imaging (SPI) and multipoint (MP) k-space mapping [35][36][37][38][39][40][41] and have permitted high-resolution images in a variety of solid materials to be obtained, including direct imaging of polymer samples. 23,[42][43][44][45][46][47][48][49] A benefit of using NMRI is the ability to couple traditional NMR spectroscopy techniques with imaging to provide a measurement of local nuclei spin behavior at a particular position (image voxel) in addition to measuring simple spin concentration or density. One common example is incorporating different NMR pulse sequences to provide image contrast or directly measure NMR spin relaxation parameters.…”

Section: Introductionmentioning

confidence: 99%

“…Parameter-related images are also known as material property images (MAP images). 20 Examples of relaxation maps in polymers include T 1F studies of cross-linking in natural rubbers and polybutadiene, 23,[42][43][44] T 2 maps of cross-link density in rubber and polyisobutylene, 20,33 multiple quantum-filtered and T 2 maps of strained elastomers and tendons, 45,47,58 T 2 maps of solvent permeation, 33,49 aging and boundary migration in natural rubbers, 46,59 and T 1 and T 2 maps of anisotropic molding effects in high-density polyethylene (HDPE). 48 The use of NMRI to investigate polymer aging and degradation has been more limited.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Relaxation Nuclear Magnetic Resonance Imaging Investigation of Heterogeneous Aging in a Hydroxy-Terminated Polybutadiene-Based Elastomer

et al. 2005

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Relaxation nuclear magnetic resonance imaging (R-NMRI) was employed to investigate the effects of thermooxidative aging in a hydroxy-terminated polybutadiene (HTPB)-based elastomer. A series of three-dimensional (3D) Hahn-echo-weighted single-point images (SPI) of the elastomer were utilized to generate a 3D parameter map of the aged material. NMR spin-spin relaxation times (T 2) were measured for each voxel producing a 3D NMR parameter (T2) map of the aged polymer. These T2 maps reveal a dramatic reduction of local polymer mobility near the aging surface with the degree of T2 heterogeneity varying as a function of aging. Using correlations between NMR T2 and material modulus, the impact of this heterogeneous thermooxidative aging on the material properties is discussed.

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Nuclear Magnetic Resonance

Demco

Blümich

2004

Encyclopedia of Polymer Science and Technology

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This article presents the basic principles of nuclear magnetic resonance (NMR) and the application of NMR techniques to polymer problems. This includes one‐dimensional NMR studies of molecular motions and dynamic order, studies of viscoelastic polymers by two‐dimensional NMR spectroscopy, and NMR imaging methods. The emphasis is on studies of viscoelastic polymers for which NMR can provide information on such important areas as the chain dynamics in elastomers, the local structure, residual couplings (induced by chemical cross‐links and topological constraints), dynamic order parameters, internuclear distances, intermolecular interactions (which are important for instance for the miscibility), the effects of fillers on molecular motions, and segmental orientation under mechanical stress and others.

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Single-point imaging of vulcanized boundary in rubber

Cited by 6 publications

References 16 publications

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.

Relaxation Nuclear Magnetic Resonance Imaging Investigation of Heterogeneous Aging in a Hydroxy-Terminated Polybutadiene-Based Elastomer

Nuclear Magnetic Resonance

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