scholarly journals Crosslink the Novel Group of Polymeric Binders BioCo by the UV-radiation

2016 ◽  
Vol 16 (2) ◽  
pp. 85-88
Author(s):  
B. Grabowska ◽  
K. Kaczmarska ◽  
A. Bobrowski ◽  
Ż. Kurleto-Kozioł ◽  
Ł. Szymański
Keyword(s):  
Uv Radiation ◽  
Uv Curing ◽  
Polymer Composition ◽  
Cross Linking ◽  
Entire Volume ◽  
Acid Sodium Salt ◽  
Polymeric Binders ◽  
Ft Ir ◽  
Mineral Matrix ◽  
The Cross

Abstract The spectroscopic FT-IR and FT-Raman methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands (as a novel group binders BioCo). The cross-linking was performed by physical agent, applying the UV-radiation. The results of structural studies (IR, Raman) confirm the overlapping of the process of cross-linking polymer composition PAA/CMS-Na in UV radiation. Taking into account the ingredients and structure of the polymeric composition can also refer to a curing process in a binder - mineral matrix mixture. In the system of binder-mineral matrix under the influence of ultraviolet radiation is also observed effect of binding. However, the bonding process does not occur in the entire volume of the investigated system, but only on the surface, which gives some possibilities for application in the use of UV curing surface of cores, and also to cure sand moulds in 3D printing technology.

scholarly journals Studies on The Renewability of Polymeric Binders for Foundry

2012 ◽  
Vol 12 (3) ◽  
pp. 37-42 ◽  
Author(s):  
B. Grabowska ◽  
K. Kaczmarska ◽  
A. Bobrowskia
Keyword(s):  
Microwave Radiation ◽  
Bending Strength ◽  
Cross Linking ◽  
Structural Studies ◽  
Strength Tests ◽  
Before And After ◽  
Polymeric Binders ◽  
Ft Ir ◽  
Moulding Sand ◽  
The Cross

Abstract In this paper the results of studies of polymeric binders on the example of the new BioCo2 binder, including the problem of its renewability, are presented. The results of structural studies (FT-IR) for the BioCo2 binder before and after crosslinking, and bending strength tests Rg u fresh and renewed cured molding sands with BioCo2 binder are discussed. The cross-linking binder and curring of moulding sand was carried out by physical agents (microwave radiation, temperature). On the basis of obtained results was shown that it is possible to restore the initial properties of the adhesive of BioCo2 binder. The initial properties of moulding sand can be achieved, after the cross-linking binders and after curing in the moulding sands with bioCo2 binder , by supplementing the moulding sand composition by the appropriate amount of water.

scholarly journals Synthesis of epoxy resins derivatives of naphthalene-2,7-diol and their cross-linked products

2019 ◽  
Vol 138 (6) ◽  
pp. 4349-4358 ◽  
Author(s):  
K. Fila ◽  
M. Gargol ◽  
M. Goliszek ◽  
B. Podkościelna
Keyword(s):  
Fourier Transform ◽  
Epoxy Resins ◽  
Attenuated Total Reflectance ◽  
Cross Linking ◽  
Total Reflectance ◽  
Before And After ◽  
Ft Ir ◽  
The Cross ◽  
Derivatives Of ◽  
Epoxy Groups

Abstract The aim of this study was the synthesis of three different epoxy compounds based on naphthalene-2,7-diol (2,7-NAF.EP, 2,7-NAF.WEP, 2,7-NAF.P.EP) and then their cross-linking by triethylenetetramine (TETA). All epoxides were prepared by the reaction of naphthalene-2,7-diol with epichlorohydrin but under different conditions and with other catalysts. The structures of the obtained compounds before and after the cross-linking reactions were confirmed by the attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR). The ATR/FT-IR spectra of cross-linked compounds show disappearance of the C–O–C bands (about 915 cm−1) derived from the epoxy groups. DSC and TG/DTG measurements indicated that the obtained materials possess good thermal resistance; they are stable up to about 250 °C. The hardness of the cross-linked products was determined using the Shore D method. The highest value of hardness was obtained for the 2,7-NAF.EP-POL. Additionally, the UV–Vis absorption spectra of the obtained polymers were registered and evaluated.

scholarly journals UV Radiation Induced Cross-Linking of Whey Protein Isolate-Based Films

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Markus Schmid ◽  
Tobias Konrad Prinz ◽  
Kerstin Müller ◽  
Andreas Haas
Keyword(s):  
Whey Protein ◽  
Uv Radiation ◽  
Reference Sample ◽  
Barrier Properties ◽  
Protein Isolate ◽  
Cross Linking ◽  
Protein Films ◽  
Disordered Protein ◽  
Radiation Induced ◽  
The Cross

Casted whey protein films exposed to ultraviolet irradiation were analyzed for their cross-linking properties and mechanical and barrier performance. Expected mechanical and barrier improvements are discussed with regard to quantification of the cross-linking in the UV-treated whey protein films. Swelling tests were used to determine the degree of swelling, degree of cross-linking, and cross-linking density. When the UV radiation dosage was raised, a significant increase of the tensile strength as well as an increase in Young’s modulus was observed. No significant changes in water vapor and oxygen barrier properties between the UV-treated films and an untreated reference sample could be observed. The cross-linking density and the degree of cross-linking significantly increased due to UV radiation. Combined results indicate a disordered protein network in cast films showing locally free volume and therefore only minor mechanical and barrier improvements.

A Hydroxyapatite-Collagen Composite Useful to Make Bioresorbable Scaffolds for Bone Reconstruction

2010 ◽  
Vol 76 ◽  
pp. 133-138 ◽  
Author(s):  
Giulio D. Guerra ◽  
Caterina Cristallini ◽  
Elisabetta Rosellini ◽  
Niccoletta Barbani
Keyword(s):  
Weight Ratio ◽  
Average Diameter ◽  
Cross Linking ◽  
Bone Reconstruction ◽  
Scanning Calorimetry ◽  
Bioresorbable Scaffolds ◽  
Micro Particles ◽  
Ft Ir ◽  
The Cross ◽  
The Stability

Composites between hydroxyapatite (HA) and collagen (Col) may be used to make bioresorbable scaffolds for bone reconstruction. A suspension of micro-particles (average diameter ≅ 30 µm) of HA annealed at 1100°C in Col solution (80:20 HA to Col weight ratio) was manufactured in films by casting, and then some films were cross-linked by glutaraldehyde vapours. Cross-linked sponges were obtained by treating the suspension with transglutaminase, and by lyophilizing the so obtained gel. Characterization by scanning electron microscopy, water sorption test, Col release in water, thermogravimetric analysis and differential scanning calorimetry shows that the cross-linking enhances the stability of the composite. Conversely, neither the interactions between HA and Col, detected by spotlight FT-IR, nor the degradation by collagenase, which is a requirement for the bioresorbibility, are affected by the cross-linking.

scholarly journals Incorporation of Decanethiol-Passivated Gold Nanoparticles into Cross-Linked Poly(Dimethylsiloxane) Films

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Motohiro Tagaya ◽  
Masaru Nakagawa
Keyword(s):  
Composite Film ◽  
Au Nanoparticles ◽  
Au Nanoparticle ◽  
Cross Linking ◽  
Pdms Film ◽  
Dispersion State ◽  
Ft Ir ◽  
Cross Linker ◽  
The Cross ◽  
Vinyl Group

Cross-linking degree of a poly(dimethylsiloxane) (PDMS) film was controlled, and the incorporation of hydrophobic decanethiol-passivated gold (Au) nanoparticles into the film was investigated. FT-IR spectra indicated that the hydrosilylation reaction between a vinyl group and a hydrosilyl group occurred with the cross-linking. The swelling degree of the film in toluene changed with a cross-linker concentration, indicating the control of the cross-linking degree of PDMS film. By EDX analysis, the amount of incorporated Au nanoparticles increased with decreasing a cross-linker concentration, indicating the enlarged free volume of the film. The Au nanoparticle-PDMS composite film containing a cross-linker at 6 wt% showed brown color attributed to plasmon resonance of Au nanoparticles, suggesting the Au nanoparticles in the film at monodispersion state. The UV-visible absorbance of the composite film decreased without spectralshift by swelling with toluene, and the changes were reversible. The aggregation among Au nanoparticles in the composite film after calcination also depended on the cross-linking degree. Thus, the control of cross-linking degree of PDMS film successfully leaded to a simple way of fabricating the Au nanoparticle-PDMS composite film at the mono-dispersion state.

scholarly journals Studies on Novel Methods for Formulating Novel Cross-Linked Hydrogel Films of Hyaluronic Acid

Cosmetics ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 59
Author(s):  
Rashid ◽  
Albayati ◽  
Dodou
Keyword(s):  
Hyaluronic Acid ◽  
Uv Radiation ◽  
High Water ◽  
Hydroxyl Group ◽  
Cross Linking ◽  
Alkaline Conditions ◽  
The Cross ◽  
User Friendly ◽  
Pt Films ◽  
Hydrogel Films

Hyaluronic acid (HA) is a natural polysaccharide with promising applications in modern cosmetic and nutricosmetic products due to its high-water affinity, which is essential for skin hydration, as well as its biocompatibility, biodegradability, non-toxicity, and non-immunogenic nature. In this study, we investigated and optimized the method of crosslinking for formulating novel HA hydrogel films. We used Pentaerythritol Tetra-acrylate (PT) as the cross-linking agent over a range of pH values and used different cross-linking methods (Ultraviolet (UV) radiation, microwaving, and oven heating). The efficacy of the cross-linking reaction was evaluated using swelling studies and Fourier transform infrared (FTIR) spectroscopy for the characterization of the xerogel HA-PT film formulations. We found that HA-PT cross-linked hydrogels are produced under alkaline conditions (pH 11) but not under neutral or acidic conditions. Cross-linked HA-PT xerogel films using UV-irradiation showed excessive swelling indicative of inadequate cross-linking. The oven and microwaving methods produced HA-PT films with high cross-linking density. FTIR data suggest formation of ester bond between the carbonyl of the HA and hydroxyl group of the PT acrylate group. Overall, the oven method was considered better and easier than UV-radiation/microwave methods because it is safer, user-friendly and eco-friendly, and can process larger batches.

CROSS-LINKING REACTIONS OF SILICA-FILLED EPOXIDIZED NATURAL RUBBER WITH FUMARIC ACID

2016 ◽  
Vol 89 (3) ◽  
pp. 465-476 ◽  
Author(s):  
Rohani Abu Bakar ◽  
Rosiyah Yahya ◽  
Seng Neon Gan
Keyword(s):  
Natural Rubber ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Fumaric Acid ◽  
Epoxidized Natural Rubber ◽  
Lower Percentage ◽  
Cross Linking ◽  
Ft Ir ◽  
The Cross ◽  
Solvent Swelling

ABSTRACT The dual functionality of epoxide and unsaturated sites in epoxidized natural rubber (ENR) permits different types of cross-linking reactions. Besides the normal vulcanization via double bonds, alternative cross-linking reactions could take place via ring opening of epoxide groups by dicarboxylic acids and diamines. We investigated the cross-linking reactions of silica-filled ENR50 with fumaric acid. The cross-linking reactions at 160 °C were assessed using a Monsanto rheometer. Supporting evidence of the reactions was provided by Fourier transform infrared spectroscopy (FT-IR), solvent swelling, and differential scanning calorimetry (DSC) analysis. FT-IR showed new absorbance peaks of hydroxyl and ester groups in agreement with the structures expected to form during the reactions between ENR50 and fumaric acid. The increase in cross-links led to a lower percentage of solvent swelling, higher glass transition temperature, and higher torque. Incorporation of silica filler has further increased the torque due to the stiffening effect of the filler. The amorphous silica used in the current work was prepared from rice husk. Leaching of the rice husk with dilute sulfuric acid before the combustion at 600 °C for 2 h led to the production of high-purity amorphous silica (>99% SiO2).

scholarly journals Preparation of Ag NPs and Its Multifunctional Finishing for Cotton Fabric

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1338
Author(s):  
Jionglin Zhu ◽  
Hong Li ◽  
Yu Wang ◽  
Yusu Wang ◽  
Jun Yan
Keyword(s):  
Electron Microscopy ◽  
Cotton Fabric ◽  
Cotton Fabrics ◽  
Cross Linking ◽  
Natural Material ◽  
Ag Nps ◽  
X Ray ◽  
Washing Durability ◽  
Ft Ir ◽  
The Cross

To explore the combination of silver nanoparticles (Ag NPs) prepared in a green manner with cotton fabrics and the washing durability of the fabric after the combination. In this paper, the natural material, honeysuckle extract, was used as a reducing agent to prepare the Ag NPs’ solution. The structure and size of Ag NPs were analyzed using ultraviolet–visible spectrophotometry (UV–vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy characterization. The results showed that Ag+ was successfully reduced to Ag0 by the honeysuckle extract, the particle size was about 10.59 nm, and the potential was −42.9 mV, so it had strong electrostatic repulsion and good stability. Meanwhile, it was found that the synthesized Ag NPs were well coated by the honeysuckle extract, so they would not aggregate. Then, the cotton fabric was finished with Ag NPs’ solution by the dipping method using a complex of polymaleic acid (PMA) and citric acid (CA) as a cross-linking agent to fix Ag NPs on the cotton fabric. The structures of cotton fabrics before and after finishing were characterized using FT-IR, scanning electron microscopy (SEM), XRD, X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis, and the multifunctional properties of the finished cotton fabrics were explored by measuring the antibacterial rate, the wrinkle recovery angle (WRA), and the UV protection factor (UPF) value. The results show that Ag NPs were successfully loaded onto cotton fabric, and the PMA + CA compound was successfully cross-linked to the fabric. The cross-linked Ag NPs’ cotton fiber was rougher than that before cross-linking, and its TG stability improved. The PMA + CA compound fixed Ag NPs on the cotton fabric through chemical bonds, so it still had a 99% antibacterial effect against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after 50 washings. Compared with unfinished cotton fabric, the UPF value and WRA of the cross-linked Ag NPs cotton increased by 34.09 and 98°, respectively, and its color did not change much.

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