Crosslinking Effect on Thermal Conductivity of Electrospun Poly(acrylic acid) Nanofibers

Park, Yeongcheol; Lee, Suyeong; Ha, Sung Soo; Alunda, Bernard Ouma; Noh, Do Young; Lee, Yong Joong; Kim, Sangwon; Seol, Jae Hun

doi:10.3390/polym11050858

Cited by 18 publications

(11 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5–10 wt%) to be present that can obscure results, and so care was taken to evaporate water by equilibrating the material for 4 min at 100°C. The first region of 140–310°C had an observed weight loss of 25% for all samples; previous reports have linked degradation in this region to carboxylic acid side chains interactions and decomposition, cyclization to form anhydrides, decomposition and release of CH 4 and CO 2 [ 50 , 51 ]. The main chain degradation and scission of PAA is the second region of temperatures above 310°C with a mass loss of 57.41% for the 50 K MW PAA control.…”

Section: Resultsmentioning

confidence: 93%

Toward bioinspired polymer adhesives: activation assisted via HOBt for grafting of dopamine onto poly(acrylic acid)

et al. 2022

View full text Add to dashboard Cite

The design of bioinspired polymers has long been an area of intense study, however, applications to the design of concrete admixtures for improved materials performance have been relatively unexplored. In this work, we functionalized poly(acrylic acid) (PAA), a simple analogue to polycarboxylate ether admixtures in concrete, with dopamine to form a catechol-bearing polymer (PAA-g-DA). Synthetic routes using hydroxybenzotriazole (HOBt) as an activating agent were examined for their ability in grafting dopamine to the PAA backbone. Previous literature using the traditional coupling reagent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to graft dopamine to PAA were found to be inconsistent and the sensitivity of EDC coupling reactions necessitated a search for an alternative. Additionally, HOBt allowed for greater control over per cent functionalization of the backbone, is a simple, robust reaction, and showed potential for scalability. This finding also represents a novel synthetic pathway for amide bond formation between dopamine and PAA. Finally, we performed preliminary adhesion studies of our polymer on rose granite specimens and demonstrated a 56% improvement in the mean adhesion strength over unfunctionalized PAA. These results demonstrate an early study on the potential of PAA-g-DA to be used for improving the bonds within concrete.

show abstract

Section: Resultsmentioning

confidence: 93%

Toward bioinspired polymer adhesives: activation assisted via HOBt for grafting of dopamine onto poly(acrylic acid)

et al. 2022

View full text Add to dashboard Cite

show abstract

“…At 1695 cm −1 the signal of carbonyl (C=O) stretching vibration was observed. At 1634 cm −1, a band corresponds to the C=C bending mode [ 32 ]; at 1431 cm −1 , there is a signal corresponding to the C–H (CH 2 ) bending vibrations. Two bands observed at 1294 and 1236 cm −1 are characteristic of the C–O bond asymmetric and symmetric stretching vibrations of the carboxylic acid.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

et al. 2021

View full text Add to dashboard Cite

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.

show abstract

“…During the PAA–PVA cross-linking reaction, a strong ester linkage (esterification) is formed between the hydroxyl group of PVA and the carboxyl group of PAA, while the thermal treatment of PAA above 150 °C also results in the formation of strong cross-linked intra- and intermolecular anhydrides (Figure ). , …”

Section: Resultsmentioning

confidence: 99%

High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization

et al. 2021

View full text Add to dashboard Cite

This article takes a step forward in understanding the mechanisms involved during the preparation and performance of cross-linked high-drug-loading (HDL) amorphous solid dispersions (ASDs). Specifically, ASDs, having 90 wt % poorly water-soluble drug indomethacin (IND), were prepared via in situ thermal cross-linking of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) and thoroughly evaluated in terms of physical stability and in vitro supersaturation. Results showed that HDL ASDs having excellent active pharmaceutical ingredient (API) amorphous stability and prolonged in vitro supersaturation were prepared by fine tuning the cross-linking procedure. Unraveling of the processes involved during ASD’s formation shed light on the significant role of the cross-linking conditions (i.e., temperature and time), the physicochemical properties of the API, and the hydrolysis level of the cross-linker as key factors in modulating ASD’s stability. In-depth analysis of the prepared systems revealed the (1) reduction of API’s molecular motions within the cross-linked polymeric networks (through API’s strong spatial confinement), (2) the structural changes in the prepared cross-linked matrices (induced by the high API drug loading), and (3) the tuning of the cross-linking density via utilization of low-hydrolyzed PVA as the major mechanisms responsible for ASD’s exceptional performance. Complementary analysis by means of molecular dynamics simulations also highlighted the vital role of strong drug–polymer intermolecular interactions evolving among the ASD components. Overall, the impression of the complexity of in situ cross-linked ASDs has been reinforced with the excessive variation of parameters investigated in the current study, offering thus insights up to the submolecular level to lay the groundwork and foundations for the comprehensive assessment of a new emerging class of HDL amorphous API formulations.

show abstract

Crosslinking Effect on Thermal Conductivity of Electrospun Poly(acrylic acid) Nanofibers

Cited by 18 publications

References 44 publications

Toward bioinspired polymer adhesives: activation assisted via HOBt for grafting of dopamine onto poly(acrylic acid)

Toward bioinspired polymer adhesives: activation assisted via HOBt for grafting of dopamine onto poly(acrylic acid)

Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization

Contact Info

Product

Resources

About