A broad spectrum analysis of the dielectric properties of poly(2-hydroxyethyl methacrylate)

Mohomed, K.; Gerasimov, Timofey G.; Moussy, Francis; Harmon, Julie P.

doi:10.1016/j.polymer.2005.02.100

Cited by 93 publications

(80 citation statements)

References 27 publications

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“…9. Log permittivity modulus plot of Eudragit® NM30D film temperatures around T g , the Argand plot shows a deviation from the semicircular Debye model, indicating these are associated with viscoelastic dipolar relaxations (13,19). A normalized plot of M′′/M′′ (max) vs. log ν/ν (max) (Fig.…”

Section: Complex Modulusmentioning

confidence: 99%

“…In complex modulus formalism, the viscoelastic behavior and conductivity relaxations are better expressed by the complex electric modulus, M* the inverse of ε* given by (1,13):…”

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

“…A distribution of relaxation times occurs for dipolar relaxations; these can be distinguished from conductivity relaxations that follow a Debye model assuming a single relaxation time (13). The frequency dependence of M′′ vs. M′…”

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

“…given by an Argand plot shows a semicircle for a Debye model; however, dipolar relaxations deviate from the Debye model and do not show a semicircle in an Argand plot (1,12,13). Thus, based on the analysis of the M* dielectric data, the relaxation behavior of a polymer film and their kinetics can be assessed.…”

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

“…In M* formalism at lower frequencies, when isothermal M′′ plots show new peaks with a slope of +1 and M′ plots show a sharp rise in M′ values with a slope of +2, these phenomenon in DEA correlate to presence of conductivity relaxation (13,19). A similar observation was evident in the isothermal log M′′ plot (Fig.…”

Section: Complex Modulusmentioning

confidence: 99%

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Relaxation Kinetic Study of Eudragit® NM30D Film Based on Complex Modulus Formalism

2015

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Abstract. This study is aimed at resolving and characterizing the primary (α) and secondary relaxations (β) in Eudragit® NM30D film based on apparent activation energies derived from complex modulus formalism using dielectric analysis (DEA). The glass transition (T g ) of the film was determined using differential scanning calorimetry (DSC). The α relaxation corresponding to T g and the β relaxations occurring below T g were probed using DEA. The occurrence of α and β relaxations in Eudragit® NM30D film was elucidated using the complex modulus of the dielectric response employing loss modulus and permittivity data. Activation energies of these relaxations and the fundamental frequency so determined support the assignment of the relaxation pattern in the Eudragit® NM30D film. DEA methodology of the complex modulus formalism is a useful tool for differentiating the α and β relaxation kinetics in Eudragits® not easily studied using traditional thermal methods such as DSC. The kinetics associated with α and β relaxations so determined will provide formulation design support for solid orals that incorporate Eudragit® polymers. As mobility changes can affect stability and diffusion, the dipolar α and β relaxations revealed through DEA analysis may enable a better correlation to functionality of Eudragit® based pharmaceutical dosage forms.

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Section: Complex Modulusmentioning

confidence: 99%

“…In complex modulus formalism, the viscoelastic behavior and conductivity relaxations are better expressed by the complex electric modulus, M* the inverse of ε* given by (1,13):…”

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

Section: Dielectric Relaxation Theorymentioning

confidence: 99%

Section: Complex Modulusmentioning

confidence: 99%

See 3 more Smart Citations

Relaxation Kinetic Study of Eudragit® NM30D Film Based on Complex Modulus Formalism

2015

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Polymer Gels from Biopolymers

Alveroğlu

Gelir

2013

Handbook of Biopolymer‐Based Materials

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Poly(HEMA)/cyclodextrin‐based hydrogels for subconjunctival delivery of cyclosporin A

Başbağ

Gümüşderelı́oğlu

Şimşek

et al. 2014

J of Applied Polymer Sci

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To enhance the solubility and ocular permeability of immunosuppressive agent, cyclosporine A (CsA), three types of delivery systems were prepared using (2‐hydroxypropyl)‐β‐cyclodextrin (HPβCD), and 2‐hydroxyethyl methacrylate (HEMA). Those systems are (i) hydrogels of HPβCD with crosslinking agent ethylene glycol diglycidylether, (ii) poly(HEMA) hydrogels, and (iii) different amounts of HPβCD‐containing poly(HEMA) hydrogels indicated as poly(HEMA‐co‐HPβCD). In the presence of HEMA, hydrogels have desired mechanical integrity with lower equilibrium content than that of hydrogels without HEMA. CsA was loaded into the HPβCD‐based hydrogels by embedding from its aqueous suspensions in higher amounts than that of the poly(HEMA) hydrogels that were loaded by CsA–HPβCD complex solution. Although the poly(HEMA) hydrogels are releasing total CsA in 3 days, long‐term release was realized from HPβCD‐based hydrogels. For subconjunctival administration, regarding to the amounts of loaded CsA, release profiles, and mechanical integrity, the most suitable system is poly(HEMA‐co‐HPβCD) hydrogels in high HPβCD content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40397.

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A broad spectrum analysis of the dielectric properties of poly(2-hydroxyethyl methacrylate)

Cited by 93 publications

References 27 publications

Relaxation Kinetic Study of Eudragit® NM30D Film Based on Complex Modulus Formalism

Relaxation Kinetic Study of Eudragit® NM30D Film Based on Complex Modulus Formalism

Polymer Gels from Biopolymers

Poly(HEMA)/cyclodextrin‐based hydrogels for subconjunctival delivery of cyclosporin A

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