scholarly journals Preparation and Characterization of Acrylic Pressure-Sensitive Adhesives Crosslinked with UV Radiation-Influence of Monomer Composition on Adhesive Properties

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 246
Author(s):  
Karolina Mozelewska ◽  
Zbigniew Czech ◽  
Marcin Bartkowiak ◽  
Małgorzata Nowak ◽  
Paulina Bednarczyk ◽  
...  

In this study, syntheses of acrylate copolymers were performed based on the monomers butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA), and acrylic acid (AA) and the second-type unsaturated photoinitiator 4-acryloyloxybenzophenone (ABP). The structure of the obtained copolymers was confirmed via FT-IR spectroscopic analysis, and the viscosity and the content of non-volatile substances were determined. The adhesive films were then coated and cross-linked using ultraviolet radiation in the UV-C range at various doses (5–50 mJ/cm2). Due to the dependence of the self-adhesive properties of the adhesive layer on the basis weight, various basis weights of the layer in the range of 30–120 g/m2 were tested. Finally, the self-adhesive properties were assessed: tack, peel adhesion, shear strength (cohesion) at 20 °C and 70 °C, as well as the SAFT test and shrinkage. The aim of the study was to determine the effect of the type of monomer used, the dose of ultraviolet radiation, and the basis weight on the self-adhesive and usable properties of the obtained self-adhesive tapes.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.


Author(s):  
Rini Hamsidi ◽  
Wahyuni Wahyuni ◽  
Adryan Fristiohady ◽  
Muhammad Hajrul Malaka ◽  
Idin Sahidin ◽  
...  

Carthamus tinctorius Linn, also known as safflower, is a plant with the potential of being used in the production of antimalarial drugs. The purpose of this study was to isolate and identify the steroid compounds in the safflower and determine its antimalarial activity in vitro. The isolation process was conducted through extraction and chromatography methods. Then, the characterization of the isolated compounds was conducted through spectroscopic techniques which include Fourier Transform Infrared Spectroscopy (FT-IR), NMR 1-D (1H and 13C-NMR), and NMR 2-D (HMQC, HMBC, and H-H COZY) as well as comparing data with the existing literatures. In addition, the tests conducted were with variations of isolate concentrations (10, 1, 0.1, 0.01, and 0.001 μg/mL) against 3D7 strain of Plasmodium falciparum. Based on the FT-IR spectroscopic data, the steroid compounds isolated from safflowers might be stigmasterols. In addition, the isolates had -OH functional group in the region of 3431 cm-1, C-O in the region of 1053 cm-1, and Csp3-H in regions of 2960, 2934, and 2865 cm-1. The NMR 1-D data showed presence of 29 carbon atoms, while the protons were 48 in number. Furthermore, the IC50 value of the compound was 34.03 μg/mL with a percentage inhibition of 43.92% against the growth of P. falciparum. Therefore, it was classified as inactive agent in inhibiting the growth of malaria parasites, however, it could be used as a marker compound in C. tinctorius Linn extract.


1998 ◽  
Vol 16 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Fu Hongxiang ◽  
Lu Gongxuan ◽  
Li Shuben

The study of the adsorption of the CrVI ion on to TiO2 not only provides information on the removal of heavy metal ions from polluted aqueous solutions; but is also useful for further investigation of the photocatalytic decontamination of the CrVI ion or of CrVI–organic species which co-exist as pollutants with TiO2 when the latter is used as a stable and highly efficient photocatalyst. It has been found that dark adsorption of the CrVI ion on to TiO2 is mainly dependent on the acidity of the system and the initial concentration of the CrVI ion. As the pH of the system increases, so the extent of adsorption of the CrVI ion decreases. The greatest adsorption was obtained with an initial CrVI ion concentration of ca. 300 μmol/l. The presence of phosphate or acetate ions in the system dramatically decreases the adsorption efficiency of the CrVI ion. In contrast, the addition of formic acid leads to a limited increase in the extent of CrVI ion adsorption. Other organic ions and organic compounds examined showed no interference in CrVI ion adsorption. FT-IR spectroscopic methods were used for the characterization of CrVI ion adsorption on to TiO2.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4413
Author(s):  
Marcin Bartkowiak ◽  
Zbigniew Czech ◽  
Hyun-Joong Kim ◽  
Gyu-Seong Shim ◽  
Małgorzata Nowak ◽  
...  

The use of ultraviolet radiation (UV) technology for the crosslinking of acrylic pressure-sensitive adhesives (PSA) is the one of various crosslinking methods, being the alternative to the conventional crosslinking process of solvent-based acrylic systems. It also requires a photoinitiator to absorb the impinging UV and induce photocrosslinking. As previously mentioned, a photoinitiator is one of the important and necessary components in UV-inducted crosslinking of acrylic pressure-sensitive adhesives. The activity of multifunctional conventional saturated photoinitiators of type I and type II, especially benzophenone-based in the photoreactive UV-crosslinkable acrylic PSA was described. The effect of the multifunctional type-II photoinitiators on the acrylic PSA, such as tack, peel adhesion and shear strength were summarized.


2000 ◽  
Vol 629 ◽  
Author(s):  
Kenneth R. Shull ◽  
Alfred J. Crosby ◽  
Cynthia M. Flanigan

ABSTRACTTriblock copolymers with poly (methyl methacrylate) (PMMA) end blocks and a poly (n-butyl acrylate) (PnBA) midblock have been synthesized as model pressure sensitive adhesives and thermoreversible gels. These materials dissolve in a variety of alcohols at temperatures above 60 °C to form freely flowing liquids. At lower temperatures the PMMA end-blocks associate so that the solutions form ideally elastic solids. In our case the solvent is 2-ethylhexanol, polymer volume fractions vary from 0.05 to 0.3, and the elastic moduli are close to 10,000 Pa. We have conducted three types of experiments to elucidate the origins of adhesion and bulk mechanical properties of these materials: 1) Weakly adhering gels: The adhesive properties of the gels are dominated by the solvent. Very little adhesion hysteresis is observed in this case, although we do observe hysteresis associated with the frictional response of the layers. 2) Strongly adhering gels. By heating the gels in contact with a PMMA surface, it is possible to bond the gels to the surface. Development of adhesion as the PMMA blocks penetrate into the PMMA substrate can be probed in this case. The cohesive strengths of the gels are found to be substantially greater than their elastic moduli, so that these materials can be reversibly extended to very high strains. These properties have enabled us to probe the origins of elastic shape instabilities that play a very important role in the behavior of thin adhesive layers. 3) Dried gels – model pressure sensitive adhesives. By removing the solvent at low temperatures, the underlying structure of the gel is preserved, giving a thin elastic layer with excellent performance as a pressure sensitive adhesive. Resistance to adhesive failure, expressed as a velocity-dependent fracture energy, greatly exceeds the thermodynamic work of adhesion. This energy is further magnified by ‘bulk’ energy dissipation when the stress applied to the adhesive layer exceeds its yield stress.


2012 ◽  
Vol 8 (8) ◽  
pp. 2050 ◽  
Author(s):  
Shota Kudo ◽  
Jose M. M. Caaveiro ◽  
Takamitsu Miyafusa ◽  
Shuichiro Goda ◽  
Keisuke Ishii ◽  
...  

2009 ◽  
Vol 11 (3) ◽  
pp. 1-4
Author(s):  
Zbigniew Czech ◽  
Agnieszka Butwin

Butyl acrylate/4-acryloyloxy benzophenone copolymers as photoreactive UV-crosslinkable pressure-sensitive adhesives It has previously been shown that copolymers of butyl acrylate with 4-acryloyloxy benzophenone can be used as pressure-sensitive adhesives (PSAs). This paper presents the synthesis and application of a solvent-borne polymer system for the preparation of photoreactive UV-crosslinkable acrylic pressure-sensitive adhesives. Butyl acrylate/benzophenone copolymers with molecular mass in the range 180 000 to 480 000 Dalton were prepared by carrying out free-radical solution polymerization. These copolymers were found to be tacky but in some cases to possess insufficient cohesive strength after UV-crosslinking to be useful as PSAs. The other copolymers resulted in materials with the balance of cohesive and adhesive characteristics required of good PSAs. Some of the parameters affecting the pressure-sensitive adhesive properties of the copolymers are the concentration of 4-acryloyloxy benzophenone, the molecular mass of the polymeric components, the UV-reactivity, and properties such as tack, peel adhesion, and cohesion.


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