Dehydration of water‐plasticized poly(vinyl alcohol) systems: particular behavior of isothermal mass transfer

Zhang, Hao; Wang, Qi; Li, Li

doi:10.1002/pi.2498

Cited by 30 publications

(22 citation statements)

References 32 publications

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“…5). In contrast, the model proposed by Zhang et al (9) with only two parameters (and a constant shape parameter) did not explain the initial stage of the drying process. Furthermore, irrespective of the size of the films, two distinct phases of the drying process were observed (Figs.…”

Section: Modeling the Drying Process In A Convection Ovencontrasting

confidence: 39%

“…The steep and shallow regions of the K d curves can be attributed to faster and slower kinetics of mass transfer (drying), as explained above. Zhang et al and Guerrier et al made similar observations of a two-step process while PVA, methyl ethyl ketone, and polybutyl methacrylate polymer films were drying (9,10).…”

Section: Modeling the Drying Mechanisms Of Polymer Filmsmentioning

confidence: 50%

“…The formation of intramolecular or intermolecular hydrogen bonds in or between the solvent/water molecules with polymer scaffolds can also affect the drying kinetics. Thus, understanding the relationships between the mass transfer phenomena (drying rate) and physical changes in the polymer is very important for tailoring the physico-mechanical properties of the oral film product (9,10).…”

Section: Introductionmentioning

confidence: 99%

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Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films

2017

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Abstract.The process of drying thin polymer films is an important operation that influences the film structure and solid state, and the stability of the product. The purpose of this work was to study and model the drying kinetics of multicomponent films based on two polymers: hydroxypropyl methylcellulose (HPMC, amorphous) and polyvinyl alcohol (PVA, semicrystalline). The isothermal drying kinetics of the films at different temperatures (40, 60, and 80°C) were studied using thermo-gravimetric analysis (TGA) and convection oven methods. Solid-state characterization tools used in the study included polarization and hotstage microscopy, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The drying kinetics of HPMC and PVA films in the TGA apparatus and convection oven were comparable. The three-parameter (W max , τ, n) Hill equation successfully modeled the experimental drying kinetics. The time factor τ in the Hill equation nicely explained two drying phases in the films. Solid-state phase changes occurring in the films during dehydration had a bearing on the drying kinetics and mechanisms. TGA can be used as a simple tool to determine the end points in drying processes using ovens or tunnels. The three-parameter Hill equation explained the drying kinetics and diffusion mechanisms of the solvent through the polymer films for the first time. This study advances our understanding of film drying, in particular for pharmaceutically relevant thin films.

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Section: Modeling the Drying Process In A Convection Ovencontrasting

confidence: 39%

Section: Modeling the Drying Mechanisms Of Polymer Filmsmentioning

confidence: 50%

Section: Introductionmentioning

confidence: 99%

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Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films

2017

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“…PVA is a water-soluble and biodegradable polymer with excellent chemical resistance; as such it is an interesting material for high-tech applications (Zhang et al 2009). PVA hydrogels exhibit biocompatibility as well as a high elastic modulus even at relatively high-water concentrations.…”

Section: Introductionmentioning

confidence: 99%

Characterization of crystalline cellulose of jute reinforced poly (vinyl alcohol) (PVA) biocomposite film for potential biomedical applications

2014

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Cellulose crystals (CC) were chemically derived from jute by alkali treatment, bleaching and subsequent hydrolysis with 40 % sulfuric acid. Infrared spectroscopy (FT-IR) suggested sufficient removal of lignin and hemicellulose from the raw jute and scanning electron microscopy (SEM), and X-ray diffraction (XRD) studies demonstrated the preparation of microcrystalline cellulose. CC reinforced polyvinyl alcohol (PVA) composite was prepared by solution casting method under laminar flow. In order to maintain uniform dispersion of 3–15 % (w/w) of the CC in the composite N, N dimethylformamide (DMF) was used as a dispersant. FT-IR, XRD, SEM, thermogravimetric analysis (TG, DTG and DTA) and thermomechanical analyses (TMA) were used to characterize the CC and the composites. The study of tensile properties showed that tensile strength (TS) and modulus (TM) increase with increasing CC content up to 9 % and then decrease with the addition of a high content of CC (above 9 %) because of the aggregation of CCs in the composite. The highest TS (43.9 MPa) and TM (2,190 MPa) have been shown to be the composite prepared with 9 % CC and the lowest to be from pure PVA film 17.1 and 1470 MPa. In addition, the composites have showed no cytotoxicity that can also prohibit microbial growth and; hence, it can be a potential material for biomedical applications such as wound healing accelerators.Electronic supplementary materialThe online version of this article (doi:10.1007/s40204-014-0023-x) contains supplementary material, which is available to authorized users.

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“…Glycerol , water , ethylene glycol , lacti‐glyceride , low‐molecular‐weight PEG , MgCl 2 /glycol , urea/formamide , urea/ethanolamine , and ionic liquid 1‐butyl‐2,3‐dimethylimidazolium tetrafluoroborate were used as plasticizers for PVA. There are amide or hydroxyl groups in those plasticizers, hydrogen bonds formed between plasticizers and PVA chains, the inter‐ or intramolecular interactions in PVA reduced, resulting in the reduction of crystalline fraction and improvement of PVA performance.…”

Section: Introductionmentioning

confidence: 99%

Preparation and properties of PVA films using hydroxyalkylformamides as the plasticizers

Dai

Wang

2017

Polymer Engineering & Sci

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N,N‐Bis(2‐hydroxyethyl)formamide, N‐(2‐hydroxyethyl)formamide (HF), N‐(2‐hydroxyethyl)‐N‐methylformamide, and N‐(2‐hydroxypropyl)formamide were used as poly(vinyl alcohol) (PVA) plasticizers to prepare PVA films by casting method. The four synthesized compounds were hydroxyalkylformamides (HAF). Fourier‐transform infrared spectra demonstrated that hydrogen bond interaction between the new plasticizers HAF and PVA occurred. The crystallinity of PVA and PVA film was characterized by X‐ray diffraction. Differential scanning calorimetry showed that HAF could decrease the melting point (Tm) of PVA. For PVA films with the same weight content plasticizer, the lower the molecular mass of plasticizer was, the lower the Tm of PVA was. The Tm of HF‐plasticized PVA was lower than that of traditional glycerol‐plasticized PVA. Generally, water‐vapor resistance of HAF‐plasticized PVA film was better than that of glycerol‐plasticized PVA film. The mechanical properties of PVA films stored at different relative humidity were studied. HAF were effective plasticizers for PVA. POLYM. ENG. SCI., 58:E145–E150, 2018. © 2017 Society of Plastics Engineers

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Dehydration of water‐plasticized poly(vinyl alcohol) systems: particular behavior of isothermal mass transfer

Cited by 30 publications

References 32 publications

Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films

Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films

Characterization of crystalline cellulose of jute reinforced poly (vinyl alcohol) (PVA) biocomposite film for potential biomedical applications

Preparation and properties of PVA films using hydroxyalkylformamides as the plasticizers

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