An infrared spectroscopic comparison of cis- and trans-CHCH and vinyl CHCH2 group frequencies of some hexenes, heptenes, and stereospecific and non-stereospecific polybutadienes

Nava, D.; Parada, Tamara Rajmankina de; González, Edgar; Boscàn, Neida; Cruz, Carlos de la

doi:10.1016/0584-8539(96)01676-5

Cited by 12 publications

(7 citation statements)

References 13 publications

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“…The peak at 973 cm À1 is related to u(¼C-H) for acyclic trans double bonds, as also observed for a polybutadiene homopolymer with 55% of trans-1,4 units ( Fig. 5b) [17,19,20].…”

Section: Concentration Of Double Bondssupporting

confidence: 71%

Thermal oxidation of Poly(dicyclopentadiene)– kinetic modeling of double bond consumption

Huang

David

Gac

et al. 2019

Polymer Degradation and Stability

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This paper reports chemical changes that occur in polydicyclopentadiene during thermal oxidation at several temperatures and oxygen pressures. A particular attention was paid to the double bond consumption since these latter are associated with crosslinking and subsequent changes in mechanical properties. A kinetic model was derived from the experimental results. Its rate constants were assessed from the "inverse approach" based on their selective identification under specific ageing conditions (for example under oxygen excess). The resulting model satisfactorily describes both carbonyl formation and double bond consumption for a wide range of temperature and oxygen pressure for the first time. This can be exploited to predict the changes of local mechanical properties.

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“…The peak at 973 cm À1 is related to u(¼C-H) for acyclic trans double bonds, as also observed for a polybutadiene homopolymer with 55% of trans-1,4 units ( Fig. 5b) [17,19,20].…”

Section: Concentration Of Double Bondssupporting

confidence: 71%

Thermal oxidation of Poly(dicyclopentadiene)– kinetic modeling of double bond consumption

Huang

David

Gac

et al. 2019

Polymer Degradation and Stability

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“…Thus, the extent of polymerization (Ep) was determined by comparing changes in the loss of absorbance of a relatively isolated peak at 1318 cm −1 , that represents the trans p(=CH)s in-plane=CH deformations [21]. The method used to determine conversion using 1318 cm −1 absorption peak was that of determining the absorption of the peak height with respect to a baseline drawn between the troughs in either side of the peak (Fig.…”

Section: Methodsmentioning

confidence: 99%

Effects of quaternary ammonium-methacrylates on the mechanical properties of unfilled resins

et al. 2014

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Objectives Adding antimicrobial/anti-MMP quaternary ammonium methacrylates (QAMs) to comonomer blends should not weaken the mechanical properties of dental resins. This work evaluated the degree conversion and mechanical properties of BisGMA/TEGDMA/HEMA (60:30:10) containing 0–15 mass% QAMs A–E (A:2-acryloxyethyltrimethyl ammonium chloride; B:[3-(methacryloylamino)propyl]trimethylammonium chloride; C:[2-(methacryloxy)ethyl] trimethyl ammonium chloride; D:diallyldimethyl ammonium chloride; E:2-(methacryloyloxy) ethyltrimethyl ammonium methyl sulfate. Methods Unfilled resins with and without QAM were placed on ATR-FTIR and light-polymerized for 20 s in a thin film t 30°C. Unfilled resin beams were casted from square hollow glass tubings. Half of the beams were tested after 3 days of drying (control); the other half were tested wet after 3 days of water storage. Results Addition of QAMs in control resins significantly increased conversion 600s after light termination, with the exception of 5% MAPTAC (p<0.05). Increase of QAM content within a formulation significantly increased conversion. Control beams gave dry Young’s moduli of ~700 MPa. Addition of 5, 10 or 15 mass% QAMs produced significant reductions in dry Young’s moduli except for 5% B or C. 15 mass% A, B and C lowered the wet Young’s moduli of the resin beams by more than 30%. The ultimate tensile stress (UTS) of control dry resin was 89±11 MPa. Addition of 5–10 mass% QAMs had no adverse effect on the dry UTS. After water storage, the UTS of all resin blends fell significantly (p<0.05), especially when 15 wt% QAMs was added. Control dry beams gave fracture toughness (KIC) values of 0.88±0.1 MPa√m. Wet values were significantly higher at 1.02±0.06 (p<0.05). KIC of dry beams varied from 0.85±0.08 at 5% QAMs to 0.49±0.05 at 15% QAMs. Wet beams gave KIC values of 1.02±0.06 MPa√m that fell to 0.23±0.01 at 15% QAMs. Significance Addition of 10% QAMs increased the degree of conversion of unfilled resins, but lowered wet toughness and UTS; addition of 15% QAMs lowered the mechanical properties of wet resins below acceptable levels.

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“…Mean pore size, specific pore volume and specific surface area (S BET ) of silica and stationary phase non-irradiated and irradiated by microwave radiation at power 663 W and 20 min microwave irradiation time sharp bands at 728, 966 and 911 cm −1 , respectively[41]. The region characteristic of the silica, near 3400 cm −1 is due to vibrations of the hydroxyl groups having a hydrogen bridge to physically adsorbed water.…”

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confidence: 99%

Microwave-immobilized polybutadiene stationary phase for reversed-phase high-performance liquid chromatography

Lopes

Collins

Jardim

2004

Journal of Chromatography A

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An infrared spectroscopic comparison of cis- and trans-CHCH and vinyl CHCH2 group frequencies of some hexenes, heptenes, and stereospecific and non-stereospecific polybutadienes

Cited by 12 publications

References 13 publications

Thermal oxidation of Poly(dicyclopentadiene)– kinetic modeling of double bond consumption

Thermal oxidation of Poly(dicyclopentadiene)– kinetic modeling of double bond consumption

Effects of quaternary ammonium-methacrylates on the mechanical properties of unfilled resins

Microwave-immobilized polybutadiene stationary phase for reversed-phase high-performance liquid chromatography

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