Quantitation of microstructure of novolac resins: Development of improved one‐ and two‐dimensional NMR methodologies

Roy, Debmalya; Pk, Basu; Raghunathan, P.; Eswaran, S. V.

doi:10.1002/app.13247

Cited by 8 publications

(9 citation statements)

References 13 publications

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“…As expected, the aliphatic methylene signals of the side chain of cardanol at ␦ ϭ 1.2 ppm are connected with the 13 C chemical shift at 22.2 ppm. The signals of the methyl protons on the aromatic moiety of m-cresol observed at ␦ ϭ 2.1 and 2.3 ppm (attributed to the "hindered" and "unhindered" methylene protons) are correlated well with the 13 C chemical shifts at 20.8 and 19.4 ppm, 12 whereas the signals attributed to the terminal methyl group of the side chain of cardanol at ␦ ϭ 0.8 ppm correlate with the 13 C chemical shift at 13.9 ppm.…”

Section: Resultsmentioning

confidence: 70%

“…We thus focused our attention on the aliphatic region of the spectrum. In Table II, the 13 (Fig. 4).…”

Section: Resultsmentioning

confidence: 98%

“…3). Signals in the aromatic region arising out of m-cresol and cardanol components of the resin thus have almost similar 13 C chemical shift values, and it is very difficult to identify the individual peaks arising out of m-cresol and cardanol. In the 1 H-NMR spectrum ( Fig.…”

Section: Resultsmentioning

confidence: 98%

“…Calculations based only on the intensities of signals of the 13 C-NMR spectrum are not usually reliable because of (i) the low natural abundance of 13 C nucleus and (ii) the nuclear Overhauser effect (NOE) and the consequent unequal polarization transfer from the attached hydrogen to carbon atom. 9,13 Calculations based on 1 H-NMR intensities would be much more dependable for quantitative estimation of the incorporation of the different monomers in the resin. The exact assignments of the 1 H-NMR chemical shifts are thus very important, particularly in the case of polymers, because the range of molecular weights (higher P.D.…”

Section: Chemicalmentioning

confidence: 99%

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Cashew nut shell liquid–based tailor‐made novolac resins: Polymer morphology quantitation by 1‐D and 2‐D NMR techniques and performance evaluation

Roy¹,

Pk²,

Raghunathan³

et al. 2003

J of Applied Polymer Sci

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ABSTRACT:The application of cashew nut shell liquid (CNSL) and CNSL-based polymers in the burgeoning microelectronics industry is rare. "High ortho" alternating and semialternating tailor-made novolac copolymers based on CNSL and m-cresol and/or p-cresol and have been made and successfully used as photoresists for microlithography. The microstructure of one of the representative m-cresol copolymer is exhaustively elucidated based on 1-D and 2-D NMR techniques. Incorporation of different monomers in the resin backbone has been quantitatively estimated based on an improved NMR methodology. The lithographic performance of photoresists using novolac resins based on cardanol (fractionated CNSL) and diazonaphthoquinone ester was also evaluated.

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Section: Resultsmentioning

confidence: 70%

“…We thus focused our attention on the aliphatic region of the spectrum. In Table II, the 13 (Fig. 4).…”

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 98%

Section: Chemicalmentioning

confidence: 99%

See 2 more Smart Citations

Cashew nut shell liquid–based tailor‐made novolac resins: Polymer morphology quantitation by 1‐D and 2‐D NMR techniques and performance evaluation

Roy¹,

Pk²,

Raghunathan³

et al. 2003

J of Applied Polymer Sci

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“…program written in Qbasic. 19,20 The degree of conversion was found to be [ 582.6 ð 100 / 216 ð 3 ] D 81.6% in this case.…”

Section: Resultsmentioning

confidence: 87%

Quantitative estimation of the degree of derivatization: an alternative methodology using 1‐D and 2‐D NMR experiments

Roy

Raghunathan³

et al. 2003

Magnetic Reson in Chemistry

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The precise estimation of the degree of derivatization of functional groups in polymers is important for determining their macroscopic properties. In this work, the quantitative estimation of the extent of esterification of novolac copolymers with di-tert-butyl dicarbonate was studied. Although the extent of esterification has been calculated previously by quantifying the signals from FT-IR and UV-Vis spectroscopy, these were restricted to monitoring the progress of the derivatization process. The 13C NMR signal intensities from the inverse-gated 1H-decoupled NMR spectrum have been used recently for the quantitative estimation of the degree of esterification of polymers. An alternative methodology has been suggested by us based on the fully relaxed 1H chemical shift intensities. However, since the proton signals of novolac resins are generally broad and overlapping, the proton decoupled 13C NMR spectrum was used to identify the 1H NMR signals using the 2-D HSQC technique. A TOCSY experiment was also performed to confirm further the 1H NMR signal assignments and, finally, the deconvoluted 1H NMR spectrum was used for the calculation of the extent of derivatization.

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Modification of conductivity of P3HT by addition of endometallo fullerene

Roy¹,

Tripathi²,

Saraiya³

et al. 2009

J of Applied Polymer Sci

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Germanium endometallo fullerene was synthesized by arcing Ge-impregnated graphite rod as anode and pure graphite rod as cathode. Photoluminescence (PL) and resistance measurements suggest that there are effective interactions at the interface of Ge endometallo fullerene and poly 3-hexyl thiophene (P3HT). Four-fold enhancement of conductance has been found by adding just one weight percentage of Ge endometallo fullerene in the P3HT matrix at room temperature. However, at lower and higher temperatures, the enhancement in conductivity is low compared with room temperature, indicating the efficient charge transfer across the interface at the temperature range of 300-350 K. Atomic force microscopy (AFM) images also confirm the fact that temperature makes the more ordered heterojunctions between P3HT and Ge endohedral metallofullerene, which, in turn, trigger charge separation across interfaces. A sharp quenching in PL intensity of P3HT at room temperature by adding Ge endometallo fullerene indicates a strong interaction between the two and this composite material can be useful in photovoltaic cell.

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Quantitation of microstructure of novolac resins: Development of improved one‐ and two‐dimensional NMR methodologies

Cited by 8 publications

References 13 publications

Cashew nut shell liquid–based tailor‐made novolac resins: Polymer morphology quantitation by 1‐D and 2‐D NMR techniques and performance evaluation

Cashew nut shell liquid–based tailor‐made novolac resins: Polymer morphology quantitation by 1‐D and 2‐D NMR techniques and performance evaluation

Quantitative estimation of the degree of derivatization: an alternative methodology using 1‐D and 2‐D NMR experiments

Modification of conductivity of P3HT by addition of endometallo fullerene

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