A molecular mechanics study on rotational motions of side groups in poly(methyl methacrylate)

Heijboer, J.; Baas, J. M. A.; Graaf, B. van de; Hoefnagel, M. A.

doi:10.1016/0032-3861(87)90207-2

Cited by 75 publications

(59 citation statements)

References 40 publications

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“…The decrease in the values of E' and E" for the PMMA/CAP10% blend is a sign of more freedom in the polymer chain movement (Heijboer et al 1987), leading to decreased hardness of the blend. …”

Section: Dynamic Mechanical Analysismentioning

confidence: 99%

“…This is apparent on the E' curve by the absence of the three deformations within the glassy region. In other words, the polymeric side groups are not able to rotate about the C-C bonds, so the molecular side groups behave as rigid crosslinks (Heijboer et al 1987;Menard 2008;Merenga and Katana 2010). At 80 °C, the pure PMMA and PMMA/CAP10% blend molecules moved to the alpha relaxation region, which is the main chain motion area.…”

Section: Dynamic Mechanical Analysismentioning

confidence: 99%

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Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

Raouf¹,

Wahab²,

Ibrahim³

et al. 2016

BioResources

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To obtain a high transmittance blend within ultraviolet and visible regions, various transparent samples of ascending percentages of polymethylmethacrylate (PMMA)/cellulose acetate propionate (CAP) were prepared by melt blending using a twin screw extruder. These blends were characterised by ultraviolet-visible spectroscopy, and the curves illustrated that the blending ratio of 10% CAP in PMMA meets the required purpose. The morphological, mechanical, and thermal properties for pure PMMA and the PMMA/CAP 10% blend were investigated using X-ray diffraction, scanning electron microscopy, dynamic mechanical analysis, and thermogravimetric analysis. The results showed that the PMMA/CAP 10% blend has an amorphous structure and low stiffness than pure PMMA. The miscible PMMA/CAP 10% blend exhibited mechanical stability below the glass transition temperature (Tg), with a slight increase in Tg value relative to that of pure PMMA. The study also demonstrated that the intermolecular interaction between blend elements has an effective influence on the physical properties of the blend.

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Section: Dynamic Mechanical Analysismentioning

confidence: 99%

Section: Dynamic Mechanical Analysismentioning

confidence: 99%

Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

Raouf¹,

Wahab²,

Ibrahim³

et al. 2016

BioResources

View full text Add to dashboard Cite

show abstract

“…As the temperature nears T g these segments begin to move and eventually, well above T g , allow the translational motion associated with the liquid state. [2][3][4] Polymer molecules with side groups may have a number of other relaxation processes in the glassy state, associated with the reorientation of these side groups. Poly͑methyl methacrylate͒ ͑PMMA͒ ͑see Fig.…”

Section: Introductionmentioning

confidence: 99%

Tacticity effects on the barriers to rotation of the ester methyl group in poly (methyl methacrylate): A deuteron magnetic resonance study

Cereghetti

Kind

Higgins

2004

The Journal of Chemical Physics

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In isotactic poly͑methyl methacrylate͒ ͑PMMA͒, we investigate the dynamics of the ester methyl groups by means of deuteron magnetic resonance ͑DMR͒ in a deuterated sample. We find that the motion of the CD 3 -group affects the deuteron spin-lattice relaxation as well as the DMR line shape in a characteristic way. Quadrupolar order spin lattice relaxation measurements between T ϭ291 K and Tϭ70 K reveal a broad temperature dependent probability distribution of autocorrelation times c for the 2 /3 reorientation. This broad distribution corresponds to a temperature independent Gaussian distribution of activation energies (E a ) with variance E a ϭ13.8Ϯ0.5 meV ͑1.33 kJ/mol͒. The line shape transition between Tϭ70 K and Tϭ23 K is explained with the freezing in of the methyl group reorientation. By comparing our results in an 88% isotactic sample with results obtained from a 50% syndiotactic, 30% atactic, and 20% isotactic sample of a previous investigation, we demonstrate the higher local order of the 88% isotactic sample, which corresponds to a ratio of 1.6 in the relative width E a /E a of the E a distribution. We show that different stereospecific forms of PMMA can be easily distinguished by the characteristics of their line shape transition between Tϭ70 K and Tϭ23 K.

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“…Os PnMA podem ser obtidos na forma amorfa ou semi-cristalina e consistem de uma cadeia principal não polar, de ramos laterais flexíveis formados por grupos polares -COO-e por grupos substituintes alquilas apolares R n =C n H 2n+1 . 1,[6][7][8][9][10][11][12] O estudo das suas propriedades foi iniciado a partir da sua produção industrial por volta de 1931 com o poli(metacrilato de metila) (R = CH 3 ) PMMA, que foi o primeiro polímero acrílico produzido industrialmente. 1 Ele foi inicialmente vendido em solução como solvente orgânico para uso como lacas e revestimento superficiais, em seguida foi desenvolvido um método econômico para a fabricação do monômero.…”

Section: 21-26unclassified

“…6 Os experimentos foram realizados em função da temperatura variando-se a estrutura química dos polímeros, para isso foram utilizados os polímeros amorfos da família dos PnMA, que são constituídos por uma cadeia principal não polar, por ramos laterais flexíveis formados por grupos polares COO e por grupos substituintes alquilas apolares R n =C n H 2n+1 . [7][8][9][10][11][12] Escolheu-se essa família de polímeros porque ela apresenta uma variação no tamanho do grupo lateral, que influencia na T g e na dinâmica molecular.…”

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Estudo das relaxações estruturais alfa e beta em poli(metacrilatos de n-alquila) utilizando-se RMN

Tozoni¹

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A molecular mechanics study on rotational motions of side groups in poly(methyl methacrylate)

Cited by 75 publications

References 40 publications

Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

Tacticity effects on the barriers to rotation of the ester methyl group in poly (methyl methacrylate): A deuteron magnetic resonance study

Estudo das relaxações estruturais alfa e beta em poli(metacrilatos de n-alquila) utilizando-se RMN

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