Configurational sequence determination of poly(isobornyl acrylate) by NMR spectroscopy

A novel synthetic approach to poly(hydrosiloxane)s via hydrolytic oxidation of primary organosilanes with a AuNPs-stabilized Pickering interfacial catalyst

“…The assignments of complex 1 H NMR signals of 1 are made by comparison with those reported for poly(isobornylacrylate). 13 The Me 2 Si (d 0.06) and CH-isobornyl (d 4.25) protons associated with PDMS and PiBA segments appear in the intensity ratio of 1.8 : 1 and is consistent with the composition of the polymer. The 29 Si NMR spectrum reveals a single resonance at d À21.9 analogous to that observed in poly(dimethylsiloxane).…”

“…The polymer, bis(hydroxyethoxypropyl)terminated PDMS (M n ¼ 5600 g mol À1 ), 2-bromoisobutyryl bromide and N,N,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDETA), phenylsilane, n-hexylsilane, cyclo-hexylsilane, triethylsilane and lithium aluminium hydride were purchased from Sigma Aldrich and used as procured. 1 H, 13 ) and polydispersity index (PDI) of the polymers were estimated using Waters gel permeation chromatography (GPC) equipped with L-2414 refractive index detector and Waters styragel HR3 and HR4 columns in series using THF as eluent (ow rate 1 mL min À1 ; polystyrene standards). Thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements were carried out in nitrogen atmosphere at a heating rate 10 C min À1 on a Perkin Elmer Thermal analysis system.…”

“…24 The difunctional macroinitiator (Br-PDMS-Br) was prepared by following the procedure reported earlier, 25 using bis(hydroxyethoxypropyl) terminated PDMS (5.0 g, 1.0 mmol), triethylamine (0.63 g, 6.0 mmol) and 2-bromoisobutyryl bromide (0.69 g, 3.0 mmol) as the starting materials. The IR, 1 H, 13 In a typical procedure, the macroinitiator, Br-PDMS-Br (1.0 g, 0.17 mmol), iBA (3.4 g, 17.0 mmol) and CuBr (0.048 g, 0.34 mmol) in dry toluene (2.0 mL) were introduced into a two-neck round bottom ask equipped with a magnetic stirrer. The contents were subjected to three freeze-pump-thaw cycles to remove oxygen and N,N,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDETA) (0.12 g, 0.68 mmol) was added while keeping the reaction mixture at 80 C. The reaction was allowed to continue for 4-5 h and the content thereaer was dissolved in THF and passed through neutral alumina column to remove the copper catalyst.…”

Stereochemical assignments of the nuclear magnetic resonance spectra of isobornyl acrylate/methacrylonitrile copolymers

“…The spectrum of the copolymer was quite complex and overlapped. The various resonance signals in the copolymers were assigned on the basis of a comparison with the spectra of PMAN27 and poly(isobornyl acrylate) (PiBA) 28. The spectrum was further resolved with the help of the DEPT‐135 NMR spectrum (Fig.…”

“…The expanded β‐methylene region in 2D HSQC spectra is given in Figure 7, and the assignments are listed in Table II. All of the assignments were carried out on the basis of a comparison with the spectra of PMAN27 and PiBA 28. The cross‐peaks 1 and 3 were assigned to NNmNN(H a ) and NNmNN(H b ) tetrads, respectively, whereas NNrNN tetrad was assigned to the cross‐peak 2.…”