Blends of hydroxypropyl methylcellulose and poly(1-vinylpyrrolidone-co-vinyl acetate): Miscibility and thermal stability

Zaccaron, Claudia Menegaz; Oliveira, Ricardo Vinícius Bof de; Guiotoku, Marcela; Pires, Alfredo T. N.; Soldi, Valdir

doi:10.1016/j.polymdegradstab.2005.02.010

Cited by 57 publications

(27 citation statements)

References 26 publications

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“…4a). These results are in accordance with those observed by Zaccaron et al 49 In the spectra of plasticized MC films, the previously mentioned region, 3600–3000 cm −1 , became broader due to the water absorption from the material (Fig. 3b).…”

Section: Resultssupporting

confidence: 93%

Mayo Clinic gastrointestinal surgery. K. A. Kelly, M. G. Sarr and R. A. Hinder (eds). 220 × 288 mm. Pp 734. Illustrated. 2004. Saunders: London. £130.00

Bozzetti

2004

British Journal of Surgery

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A novel photon‐fueled gate‐like mesoporous silica nanoparticles (MSN)‐based delivery system is reported. In this system, the malachite green carbinol base (MGCB) is immobilized on the nanochannel wall of MSN as a light‐induced hydroxide ion emitter and i‐motif DNA is grafted on the surface of MSN as a cap. Photoirradiation with 365 nm wavelength UV light makes MGCB molecules dissociate into malachite green (MG) cations and OH− ions, which induce the i‐motif DNA to unfold into the single‐stranded form due to the increase of the pH in the solution. Therefore, the pores are uncapped and the entrapped guest molecules are released. After the light is turned off, the MG cations recombine with the OH− ions and return to the MGCB forms. The pH value thus decreases and the single‐stranded DNA switches back to i‐motif structure to cap the pore again. Because of the photon‐fueled MGCB‐dependent DNA conformation changes, the i‐motif DNA‐gated switch can be easily operated by turning the light on or off. Importantly, the opening/closing protocol is highly reversible and a partial cargo release can be easily achieved at will. This proof‐of‐concept may promote the application of DNA in the controlled release and can also provide a way to design various photon‐fueled controlled‐release systems using a combination of some photoirradiated pH‐jump systems and other kinds of pH‐sensitive linkers.

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Section: Resultssupporting

confidence: 93%

Mayo Clinic gastrointestinal surgery. K. A. Kelly, M. G. Sarr and R. A. Hinder (eds). 220 × 288 mm. Pp 734. Illustrated. 2004. Saunders: London. £130.00

Bozzetti

2004

British Journal of Surgery

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“…All spectra presented bands close to 2900 cm −1 (at 2972, 2902, and 2836 cm −1 , more specifically) attributed to the axial deformation of the CeH bonds in aliphatic chains (Sakata & Yamaguchi, 2011), that is, to eCH 3 arising from the substitution of hydroxyl groups by methoxyl and hydroxypropyl ones. Absorptions related to the axial deformation of CeOeC bonds, typical in cellulose ethers, may be observed from 900 to 1300 cm −1 (Anuar, Wui, Ghodgaonkar, & Taib, 2007;Zaccaron, Oliveira, Guiotoku, Pires, & Soldi, 2005). Bands at wavenumbers ranging from 1250 to 1460 cm −1 (herein observed at 1315, 1374, 1410, and 1452 cm −1 ) are assigned to the angular deformation of CeH bonds within e(CH 2 ) n e chains (Sakata & Yamaguchi, 2011).…”

Section: Molecular Weight and Rheological Aspectsmentioning

confidence: 87%

On the effects of hydroxyl substitution degree and molecular weight on mechanical and water barrier properties of hydroxypropyl methylcellulose films

Otoni

Lorevice

Moura

et al. 2018

Carbohydrate Polymers

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In line with the increasing demand for sustainable packaging materials, this contribution aimed to investigate the film-forming properties of hydroxypropyl methylcellulose (HPMC) to correlate its chemical structure with film properties. The roles played by substitution degree (SD) and molecular weight (M) on the mechanical and water barrier properties of HPMC films were elucidated. Rheological, thermal, and structural experiments supported such correlations. SD was shown to markedly affect film affinity and barrier to moisture, glass transition, resistance, and extensibility, as hydroxyl substitution lessens the occurrence of polar groups. M affected mostly the rheological and mechanical properties of HPMC-based materials. Methocel E4 M led to films featuring the greatest tensile strength (ca., 67 MPa), stiffness (ca., 1.8 GPa), and extensibility (ca., 17%) and the lowest permeability to water vapor (ca., 0.9 g mm kPa h m). These properties, which arise from its longer and less polar chains, are desirable for food packaging materials.

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“…HPMC 603 and HPMC 615 had only one stage of degradation at T deg = 376.5 and 382.8°C, respectively, [42] measured in correspondence of 80% mass loss indicating that HPMC 603 is less thermally stable than HPMC 615. The quick loss in mass was attributed to evaporation of not-bounded moisture present on the surface of the solids.…”

Section: Tgmentioning

confidence: 99%

Thermo-physical characterization of Pharmacoat® 603, Pharmacoat® 615 and Mowiol® 4-98

Perfetti

Alphazan

Wildeboer

et al. 2011

J Therm Anal Calorim

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Hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) are important polymers in pharmaceutical, food and other industries being largely used as encapsulation agents. The characterization of two reference grades of HPMC (Pharmacoat Ò 603 and Pharmacoat Ò 615) and one reference grade of PVA (Mowiol Ò 4-98), through X-ray diffraction (XRD) and thermogravimetry (TG) is described. Specific analyses were performed by means of dynamic vapour sorption analysis of water adsorption/ desorption from vapours at 10, 25, 40, 55 and 70°C. Guggenheim-Anderson-de Boer (GAB), Brunauer-EmmettTeller (BET), Park and n-layer BET models were successfully used to fit the experimental data. The glass transition temperature as function of water content was measured by means of differential scanning calorimetry (DSC). The experimental data were analysed according to Linear, Gordon-Taylor, Fox and Roos equations. XRD

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Blends of hydroxypropyl methylcellulose and poly(1-vinylpyrrolidone-co-vinyl acetate): Miscibility and thermal stability

Cited by 57 publications

References 26 publications

Mayo Clinic gastrointestinal surgery. K. A. Kelly, M. G. Sarr and R. A. Hinder (eds). 220 × 288 mm. Pp 734. Illustrated. 2004. Saunders: London. £130.00

Mayo Clinic gastrointestinal surgery. K. A. Kelly, M. G. Sarr and R. A. Hinder (eds). 220 × 288 mm. Pp 734. Illustrated. 2004. Saunders: London. £130.00

On the effects of hydroxyl substitution degree and molecular weight on mechanical and water barrier properties of hydroxypropyl methylcellulose films

Thermo-physical characterization of Pharmacoat® 603, Pharmacoat® 615 and Mowiol® 4-98

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