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 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.

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

Synthesis of degradable network polymers containing peroxy units in the main chain or the cross-linking point

2010 ◽  
Vol 68 (1-2) ◽  
pp. 42-47 ◽  
Author(s):  
Asako Mihashi ◽  
Hiroshi Tamura ◽  
Eriko Sato ◽  
Akikazu Matsumoto
Keyword(s):  
Main Chain ◽  
Cross Linking ◽  
Network Polymers ◽  
The Cross

Synthesis of degradable network polymers containing peroxy units in the main chain or the cross-linking point

2010 ◽  
Vol 67 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Asako Mihashi ◽  
Hiroshi Tamura ◽  
Eriko Sato ◽  
Akikazu Matsumoto
Keyword(s):  
Main Chain ◽  
Cross Linking ◽  
Network Polymers ◽  
The Cross

scholarly journals Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

2021 ◽  
Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan
Keyword(s):  
Glass Transition ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Epoxy Resins ◽  
Functional Network ◽  
Cross Linking ◽  
Network Modifier ◽  
Epoxy Resin System ◽  
The Cross ◽  
The Impact

AbstractReactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.

scholarly journals The Effect of Surfactant-Modified Montmorillonite on the Cross-Linking Efficiency of Polysiloxanes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik
Keyword(s):  
Total Pore Volume ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Cross ◽  
Chain Lengths ◽  
First Time ◽  
Substituent Influence ◽  
Benzyl Substituent

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.

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