scholarly journals Modification of Collagen Derivatives with Water-Soluble Polymers for the Development of Cross-Linked Hydrogels for Controlled Release

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4067
Author(s):  
Ioanna Tzoumani ◽  
Georgia Ch. Lainioti ◽  
Alexios J. Aletras ◽  
Gabriel Zainescu ◽  
Simina Stefan ◽  
...  
Keyword(s):  
Attenuated Total Reflection ◽  
Water Soluble ◽  
Curing Temperature ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Normal Lung ◽  
Cross Linking ◽  
Collagen Hydrolysate ◽  
Water Soluble Polymer ◽  
The Cross

Novel cross-linked hydrogels were synthesized as potential materials for the development of smart biofertilizers. For this purpose, hydrogels were prepared using collagen hydrolysate recovered from tannery waste. The water-soluble polymer poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) (P(SSNa-co-GMAx)) was among others used for the cross-linking reaction that combined hydrophilic nature with epoxide groups. The synthetic procedure was thoroughly investigated in order to ensure high percentage of epoxide groups in combination with water-soluble behavior. The copolymer did not show cytotoxicity against normal lung, skin fibroblasts, or nasal polyps fibroblasts. Through the present work, we also present the ability to control the properties of cross-linked hydrogels by altering copolymer’s composition and cross-linking parameters (curing temperature and time). Hydrogels were then studied in terms of water-uptake capacity for a period up to six days. The techniques Proton Nuclear Magnetic Resonance (1H NMR), Thermogravimetric Analysis (TGA), Size Exclusion Chromatography (SEC), and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) were applied for the characterization of the synthesized copolymers and the cross-linked hydrogels. Three samples of biofertilizers based on collagen hydrolysate functionalized with P(SSNa-co-GMAx) and starch and having nutrients encapsulated (N, P, K) were prepared and characterized by physical–chemical analysis and Energy Dispersive X-ray analysis-Scanning Electron Microscope (EDAX-SEM) in terms of microstructure. Preliminary tests for application as fertilizers were performed including the release degree of oxidable organic compounds.

scholarly journals Stability of Collagen Scaffold Implants for Animals with Iatrogenic Articular Cartilage Defects

2009 ◽  
Vol 78 (4) ◽  
pp. 643-648 ◽  
Author(s):  
Josef Jančář ◽  
Lucy Vojtová ◽  
Alois Nečas ◽  
Robert Srnec ◽  
Lucie Urbanová ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Block Copolymer ◽  
Degradation Rate ◽  
Articular Surface ◽  
Water Soluble ◽  
Cartilage Defects ◽  
Cross Linking ◽  
Time Interval ◽  
Porous Scaffolds ◽  
The Cross

Synthesis and characterization of biodegradable hydrogels based on collagen modified by addition of synthetic biodegradable copolymer intended for preparation of porous scaffolds for mesenchymal stem cells used for possible implantation to animals with articular surface defects was investigated. The synthetic biodegradable tri-block copolymer used was the block copolymer of polyethylene glycol (PEG), polylactic acid (PLA), polyglycolic acid (PGA) (PEG-PLGA) endcapped with itaconic acid (ITA). The water-soluble carbodiimide and N-hydroxysuccimide system (EDC-NHS) was chosen as the cross-linking agent used to control the rate of hydrogel resorption. Dependence of the physical properties of the prepared hydrogels on the concentration of the EDC-NHS cross-linker, reaction time and concentration of PEG-PLGA-ITA copolymer was examined. Swelling behaviour, thermal stability, surface morphology and degradation rate were also characterized. Based on the obtained results, it can be concluded that increase in concentration of the cross-linking agent, as well as prolonged cross-linking time and increased amount of synthetic copolymer lead to enhanced thermal stability of the gels together with a reduced swelling ratio and degradation rate in saline. The resorption rate of these gels used in preparation of cartilage scaffolds can be controlled over a wide time interval by varying the collagen/(PEG-PLGA-ITA) blend composition or the conditions of the cross-linking reaction.

scholarly journals Photo- and Acid-Degradable Polyacylhydrazone–Doxorubicin Conjugates

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2461
Author(s):  
Maria Psarrou ◽  
Martha Georgia Kothri ◽  
Maria Vamvakaki
Keyword(s):  
Adipic Acid ◽  
Main Chain ◽  
Uv Light ◽  
Attenuated Total Reflection ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Solution Ph ◽  
Alternating Copolymer ◽  
Vis Spectroscopy ◽  
Self Assembled

Light-mediated polymer degradation has attracted considerable attention in various applications, including photo-patterning, tissue engineering and photo-triggered drug delivery. In this study, we report the synthesis and characterization of a new, linear, main-chain photo- and acid-degradable copolymer based on acylhydrazone linkages. The polymer was synthesized via a step-growth copolymerization of adipic acid dihydrazide with a bifunctional poly(ethylene glycol) bearing benzaldehyde end-groups, under mild acidic conditions, to afford a hydrophilic PEG-alt-adipic acid (PEG-alt-AA) alternating copolymer. The synthesized polymer was characterized by size exclusion chromatography, proton nuclear magnetic resonance and attenuated total reflection-Fourier transform infrared spectroscopies. The main-chain photo- and acid-induced degradation of the copolymer in dimethylsulfoxide and water, respectively, was verified by UV-vis spectroscopy at light intensities as low as 0.1 mW cm−2 at λ = 254 nm. Next, a model anticancer drug, doxorubicin (DOX), was chemically linked to the polymer chain end(s) via acylhydrazone bond(s), resulting in amphiphilic PEG-alt-adipic acid-DOX (PEG-alt-AA-DOX) polymer–drug conjugates. The conjugates were self-assembled in water to form spherical nanoparticles, as evidenced by scanning and transmission electron microscopies. The irradiation of the self-assembled PEG-alt-AA-DOX conjugates with UV light and the decrease of the solution pH resulted in the disruption of the assemblies due to the photolysis and acidolysis of the acylhydrazone bonds, and the release of the therapeutic cargo.

MECHANICAL PROPERTIES AND CURE TEST OF A NATURAL RUBBER/POLY(VINYL ALCOHOL) BLEND

2012 ◽  
Vol 85 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Sa-Ad Riyajan ◽  
Suwit Chaiponban ◽  
Sasitorn Chusri ◽  
Supayang Piyawan Voravuthikunchai
Keyword(s):  
Tensile Strength ◽  
Antibacterial Activity ◽  
Natural Rubber ◽  
Polymer Blend ◽  
Maleic Acid ◽  
Acid Content ◽  
Attenuated Total Reflection ◽  
Curing Temperature ◽  
Cross Linking ◽  
Curing Time

Abstract Properties and antibacterial activity of polymer blend films prepared from polyvinyl alcohol (PVA) and natural rubber (NR) blends, in the presence of maleic acid as a cross-linking agent were studied. The effect of the maleic acid content, curing temperature, and curing time on the properties of the polymer blend was investigated. Cross-linking between PVA and maleic acid was observed by attenuated total reflection mode–Fourier transform infrared spectroscopy at 1152 cm−1. The swelling ratio of the polymer blend decreased as a function of the increase of the maleic acid content. The tensile strength of the polymer blend increased with an increase of both the maleic acid and the curing time. The highest tensile strength of the samples was observed with 40% w/w maleic acid after a 24 h curing time at 120 °C. The elongation at the break of 60/40 NR/PVA was ∼500% at 120 °C for 1 h. In addition, the polymer blend showed good antibacterial activity with Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Acinetobacter baumannii JVC 1053 and could find many applications.

The Cross-linking of Gelatin Using a Water-soluble Carbodiimide

1957 ◽  
Vol 79 (16) ◽  
pp. 4528-4529 ◽  
Author(s):  
John C. Sheehan ◽  
Joseph J. Hlavka
Keyword(s):  
Water Soluble ◽  
Cross Linking ◽  
The Cross

Tuning of Properties of POSS-Condensed Water-Soluble Network Polymers by Modulating the Cross-Linking Ratio between POSS

2009 ◽  
Vol 42 (10) ◽  
pp. 3489-3492 ◽  
Author(s):  
Kazuo Tanaka ◽  
Kenichi Inafuku ◽  
Shigehiro Adachi ◽  
Yoshiki Chujo
Keyword(s):  
Water Soluble ◽  
Cross Linking ◽  
Network Polymers ◽  
Condensed Water ◽  
The Cross

scholarly journals Studying the Effectiveness of Polyacrylamide (PAM) Application in Hydrocarbon Reservoirs at Different Operational Conditions

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2201 ◽  
Author(s):  
Kingsley Godwin Uranta ◽  
Sina Rezaei-Gomari ◽  
Paul Russell ◽  
Faik Hamad
Keyword(s):  
Oil Recovery ◽  
Pure Water ◽  
Attenuated Total Reflection ◽  
Water Soluble ◽  
Solution Viscosity ◽  
Resonance Spectroscopy ◽  
Degree Of Hydrolysis ◽  
Water Soluble Polymer ◽  
Operational Conditions ◽  
Hydrocarbon Reservoir

The water-soluble polymer PAM (polyacrylamide) is used in enhanced oil recovery (EOR) operations. It is pumped into water injection wells to increase the viscosity of the injected water and in turn to direct more oil towards production wells. This EOR process is proven to be sensitive to operational well conditions such as hydrocarbon reservoir temperature, as well as the salinity of the injected water and/or formation water. These operational conditions lead to technical challenges ranging from the solubility of PAM in injection water to the behaviour of PAM inside the reservoir. To gain a clear picture of the functionality of PAM in EOR applications, this report characterizes its behaviour of in terms of degree of hydrolysis and changes in solution viscosity determined using Perkin Elmer spectrum 100 Fourier transform infrared-Attenuated total reflection (FTIR)-ATR and nuclear magnetic resonance spectroscopy (1H NMR) and a Fann model 35 Couette and Cole Parmer rotational viscometer, respectively. Different shear rates were investigated to determine the effect of shear on PAM gel stability. Experiments were performed for PAM mixed with formation brine at 50, 70, and 90 °C for ageing times of up to 30 days. The results indicate that the degree of hydrolysis achieved after 30 days is much higher in saline solutions than in pure water, and that this effect is more pronounced at higher temperatures. For example, after 30 days at 50 °C, the hydrolysis level was observed to be 53%, rising to 65% at 70 °C and 75% at 90 °C in PAM mixed with brines. Similar trends were observed with viscosity, where lower viscosity was observed for samples at higher temperatures and salinities. It is thus reasonable to conclude that the degree of hydrolysis causes changes in the viscosity of the polymer gel, leading to a decline in its performance as it ages.

scholarly journals Cosolvent-Driven Interfacial Polymerization for Superior Separation Performance of Polyurea-Based Pervaporation Membrane

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1179
Author(s):  
Manuel Reyes De Guzman ◽  
Micah Belle Marie Yap Ang ◽  
Shu-Hsien Huang ◽  
Fang-Chi Hu ◽  
Yu-Hsuan Chiao ◽  
...  
Keyword(s):  
Interfacial Polymerization ◽  
Water Concentration ◽  
Feed Solution ◽  
Attenuated Total Reflection ◽  
Water Soluble ◽  
Curing Temperature ◽  
Membrane Properties ◽  
Separation Performance ◽  
Permeation Flux ◽  
Water Contact

A thin-film composite (TFC) polyurea membrane was fabricated for the dehydration of an aqueous tetrahydrofuran (THF) solution through interfacial polymerization, wherein polyethyleneimine (a water-soluble amine monomer) and m-xylene diisocyanate (an oil-soluble diisocyanate monomer) were reacted on the surface of a modified polyacrylonitrile (mPAN) substrate. Cosolvents were used to tailor the membrane properties and increase the membrane permeation flux. Four types of alcohols that differed in the number of carbon (methanol, ethanol, isopropanol, and tert-butanol) were added as cosolvents, serving as swelling agents, to the aqueous-phase monomer solution, and their effect on the membrane properties and pervaporation separation was discussed. Attenuated total reflection Fourier transform infrared spectroscopy confirmed the formation of a polyurea layer on mPAN. Field emission scanning electron microscopy and surface water contact angle analysis indicated no change in the membrane morphology and hydrophilicity, respectively, despite the addition of cosolvents for interfacial polymerization. The TFC membrane produced when ethanol was the cosolvent exhibited the highest separation performance (permeation flux = 1006 ± 103 g·m−2·h−1; water concentration in permeate = 98.8 ± 0.3 wt.%) for an aqueous feed solution containing 90 wt.% THF at 25 °C. During the membrane formation, ethanol caused the polyurea layer to loosen and to acquire a certain degree of cross-linking. The optimal fabrication conditions were as follows: 10 wt.% ethanol as cosolvent; membrane curing temperature = 50 °C; membrane curing time = 30 min.

scholarly journals A novel green chemistry gelation method for polyvinyl pyrrolidone (PVP) and dimethylpolysiloxane (silicone): microwave-induced in-liquid-plasma

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24326-24335
Author(s):  
Satoshi Horikoshi ◽  
Seiya Sawada ◽  
Nick Serpone
Keyword(s):  
Green Chemistry ◽  
Chemical Method ◽  
Water Soluble ◽  
Polyvinyl Pyrrolidone ◽  
Cross Linking ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Plasma Method ◽  
Cross Links

The discovery of a water-soluble polymer that cross-links to form a gel using a novel green gelation method: the microwave-induced in-liquid-plasma method that requires neither a cross-linking agent nor an initiator as are required in the conventional chemical method.

scholarly journals Numerical Study of CH4 Generation and Transport in XLPE-Insulated Cables in Continuous Vulcanization

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2978
Author(s):  
Mohd Fuad Anwari Che Ruslan ◽  
Dong Joon Youn ◽  
Roshan Aarons ◽  
Yabin Sun ◽  
Shuyu Sun
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Curing Temperature ◽  
Cross Linking ◽  
Reaction Selectivity ◽  
Line Speed ◽  
Cooling Water Flow Rate ◽  
The Cross

In this work, we apply a computational diffusion model based on Fick’s laws to study the generation and transport of methane (CH 4 ) during the production of a cross-linked polyethylene (XLPE) insulated cable. The model takes into account the heating process in a curing tube where most of the cross-linking reaction occurs and the subsequent two-stage cooling process, with water and air as the cooling media. For the calculation of CH 4 generation, the model considers the effect of temperature on the cross-linking reaction selectivity. The cross-linking reaction selectivity is a measure of the preference of cumyloxy to proceed either with a hydrogen abstraction reaction, which produces cumyl alcohol, or with a β -scission reaction, which produces acetophenone and CH 4 . The simulation results show that, during cable production, a significant amount of CH 4 is generated in the XLPE layer, which diffuses out of the cable and into the conductor part of the cable. Therefore, the diffusion pattern becomes a non-uniform radial distribution of CH 4 at the cable take-up point, which corresponds well with existing experimental data. Using the model, we perform a series of parametric studies to determine the effect of the cable production conditions, such as the curing temperature, line speed, and cooling water flow rate, on CH 4 generation and transport during cable production. The results show that the curing temperature has the largest impact on the amount of CH 4 generated and its distribution within the cable. We found that under similar curing and cooling conditions, varying the line speed induces a notable effect on the CH 4 transport within the cable, while the cooling water flow rate had no significant impact.

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