scholarly journals Adhesive Performance of Acrylic Pressure-Sensitive Adhesives from Different Preparation Processes

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2627
Author(s):  
Irene Márquez ◽  
Núria Paredes ◽  
Felipe Alarcia ◽  
José Ignacio Velasco
Keyword(s):  
Average Particle Size ◽  
Gel Permeation Chromatography ◽  
Shear Resistance ◽  
Deformation Energy ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
Monomeric Composition ◽  
Adhesive Performance

A series of pressure-sensitive adhesives (PSAs) was prepared using a constant monomeric composition and different preparation processes to investigate the best combination to obtain the best balance between peel resistance, tack, and shear resistance. The monomeric composition was a 1:1 combination of two different water-based acrylic polymers—one with a high shear resistance (A) and the other with a high peel resistance and tack (B). Two different strategies were applied to prepare the adhesives: physical blending of polymers A and B and in situ emulsion polymerization of A + B, either in one or two steps; in this last case, by polymerizing A or B first. To characterize the polymer, the average particle size and viscosity were analyzed. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The tetrahydrofuran (THF) insoluble polymer fraction was used to calculate the gel content, and the soluble part was used to determine the average sol molecular weight by means of gel permeation chromatography (GPC). The adhesive performance was assessed by measuring tack as well as peel and shear resistance. The mechanical properties were obtained by calculating the shear modulus and determination of maximum stress and the deformation energy. Moreover, an adhesive performance index (API) was designed to determine which samples are closest to the requirements demanded by the self-adhesive label market.

Synthesis of Emulsion for Water-Based Pigment Ink Jet

2011 ◽  
Vol 380 ◽  
pp. 81-84
Author(s):  
Li Ming Zhang ◽  
Xiu Lan Xin ◽  
Wei Jiang
Keyword(s):  
Particle Size ◽  
Water Resistance ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Reactive Surfactant ◽  
Potential Value ◽  
Ink Jet ◽  
Water Based ◽  
Pigment Ink

The water-based pigment ink jet emulsion whose particle size was less than 100nm was synthesized by the polymerization of methyl methacrylate, butyl acrylate and ethylhexyl acrylate, and anionic reactive surfactant and nonionic surfactant were used as the emulsifiers. The effects of particle size and water resistance were studied. The glass transition temperature was tested by differential scanning calorimetry. The average particle size of emulsion was range from 60nm to70nm, zeta potential value was less than -60mv; viscosity was 3.5mps; water absorption was 5.9%.

scholarly journals FORMULATION AND EVALUATION OF DOXORUBICIN CONTAINING NANOGELS FOR DELIVERY TO CANCER CELLS

2018 ◽  
Vol 8 (5) ◽  
pp. 178-183
Author(s):  
Manish Kumar ◽  
Hemant K. Sharma
Keyword(s):  
Average Particle Size ◽  
Gellan Gum ◽  
Cross Linking ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Green Method ◽  
X Ray ◽  
Oppositely Charged ◽  
Chemical Cross Linking

The objective of this study is to prepare nanogels were prepared via charged gellan gum. It was prepared by in situ cross linking reaction between two oppositely charged materials by green method without use of chemical cross linking agents. The prepared nanogels were characterized by Dynamic light scattering, scanning electron microscopy, differential scanning calorimetry and X- Ray diffractometry. The prepared formulation had average particle size of 226 nm with polydispersity index of 0.3. The doxorubicin loaded nanogel demonstrated sustained release for 20 h. The prepared nanogels were hemocompatible and cyctocompatible as revealed by hemocompatibility and MTT assay respectively. All results confirmed that these nanogels can be used for cancer treatment. Keywords: Nanogel, Chitosan, Gellan gum, Doxorubicin, Cancer.

scholarly journals Structural and Viscoelastic Properties of Thermoplastic Polyurethanes Containing Mixed Soft Segments with Potential Application as Pressure Sensitive Adhesives

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3097
Author(s):  
Mónica Fuensanta ◽  
José Miguel Martín-Martínez
Keyword(s):  
Phase Separation ◽  
Potential Application ◽  
Viscoelastic Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Pressure Sensitive Adhesives ◽  
Thermoplastic Polyurethanes ◽  
Pressure Sensitive ◽  
Soft Segments

Thermoplastic polyurethanes (TPUs) were synthetized with blends of poly(propylene glycol) (PPG) and poly(1,4-butylene adipate) (PAd) polyols, diphenylmethane-4,4′-diisocyanate (MDI) and 1,4-butanediol (BD) chain extender; different NCO/OH ratios were used. The structure and viscoelastic properties of the TPUs were assessed by infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, thermal gravimetric analysis and plate-plate rheology, and their pressure sensitive adhesion properties were assessed by probe tack and 180° peel tests. The incompatibility of the PPG and PAd soft segments and the segregation of the hard and soft segments determined the phase separation and the viscoelastic properties of the TPUs. On the other hand, the increase of the NCO/OH ratio improved the miscibility of the PPG and PAd soft segments and decreased the extent of phase separation. The temperatures of the cool crystallization and melting were lower and their enthalpies were higher in the TPU made with NCO/OH ratio of 1.20. The moduli of the TPUs increased by increasing the NCO/OH ratio, and the tack was higher by decreasing the NCO/OH ratio. In general, a good agreement between the predicted and experimental tack and 180° peel strength values was obtained, and the TPUs synthesized with PPG+PAd soft segments had potential application as pressure sensitive adhesives (PSAs).

scholarly journals Balanced Viscoelastic Properties of Pressure Sensitive Adhesives Made with Thermoplastic Polyurethanes Blends

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1608 ◽  
Author(s):  
Fuensanta ◽  
Vallino-Moyano ◽  
Martín-Martínez
Keyword(s):  
Phase Separation ◽  
Viscoelastic Properties ◽  
Simple Procedure ◽  
Peel Strength ◽  
Similar Degree ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Pressure Sensitive Adhesives ◽  
Thermoplastic Polyurethanes ◽  
Pressure Sensitive

Pressure sensitive adhesives made with blends of thermoplastic polyurethanes (TPUs PSAs) with satisfactory tack, cohesion, and adhesion have been developed. A simple procedure consisting of the physical blending of methyl ethyl ketone (MEK) solutions of two thermoplastic polyurethanes (TPUs) with very different properties—TPU1 and TPU2—was used, and two different blending procedures have been employed. The TPUs were characterized by infra-red spectroscopy in attenuated total reflectance mode (ATR-IR spectroscopy), differential scanning calorimetry, thermal gravimetric analysis, and plate-plate rheology (temperature and frequency sweeps). The TPUs PSAs were characterized by tack measurement, creep test, and the 180° peel test at 25 °C. The procedure for preparing the blends of the TPUs determined differently their viscoelastic properties, and the properties of the TPUs PSAs as well, the blending of separate MEK solutions of the two TPUs imparted higher tack and 180° peel strength than the blending of the two TPUs in MEK. TPU1 + TPU2 blends showed somewhat similar contributions of the free and hydrogen-bonded urethane groups and they had an almost similar degree of phase separation, irrespective of the composition of the blend. Two main thermal decompositions at 308–317 °C due to the urethane hard domains and another at 363–373 °C due to the soft domains could be distinguished in the TPU1 + TPU2 blends, the weight loss of the hard domains increased and the one of the soft domains decreased by increasing the amount of TPU2 in the blends. The storage moduli of the TPU1 + TPU2 blends were similar for temperatures lower than 20 °C and the moduli at the cross over of the moduli were lower than in the parent TPUs. The improved properties of the TPU1 + TPU2 blends derived from the creation of a higher number of hydrogen bonds upon removal of the MEK solvent, which lead to a lower degree of phase separation between the soft and the hard domains than in the parent TPUs. As a consequence, the properties of the TPU1 + TPU2 PSAs were improved because good tack, high 180° peel strength, and sufficient cohesion were obtained, particularly in 70 wt% TPU1 + 30 wt% TPU2 PSA.

scholarly journals Acrylic Pressure-Sensitive Adhesives Containing SiO2 Nanoparticles

2013 ◽  
Vol 15 (1) ◽  
pp. 12-14 ◽  
Author(s):  
Zbigniew Czech ◽  
Agnieszka Kowalczyk ◽  
Joanna Ortyl ◽  
Jolanta Świderska
Keyword(s):  
Shear Strength ◽  
Sio2 Nanoparticles ◽  
Shear Resistance ◽  
Inorganic Filler ◽  
Pressure Sensitive Adhesives ◽  
Medical Products ◽  
Pressure Sensitive ◽  
Protective Films ◽  
Carrier Free ◽  
Peel Adhesion

The use of acrylic pressure-sensitive adhesives (PSAs) is increasing in a variety of industrial fields. They have been applied in the manufacture of mounting tapes, self-adhesive labels, protective films, masking tapes, splicing tapes, carrier-free tapes, sign and marking films, and in diverse medical products, such as pads or self-adhesive bioelectrodes. In this study, the application of SiO2 nanoparticles in acrylic PSA was investigated. The properties of the newly synthesized and modified PSA were evaluated via the tack, peel adhesion, shear-strength and shrinkage. It has been found that the nanotechnologically-reinforced systems consisting of monodisperse non-agglomerated SiO2 nanoparticles and self-crosslinked acrylic PSAs showed a great enhancement in tack, peel adhesion, shear resistance and shrinkage, without showing the disadvantages known to result from the use of other inorganic additives. In this paper we evaluate the performance of SiO2 nanoparticles with a size of about 30 nm as inorganic filler into the synthesized solvent-borne acrylic PSA.

A Calcination Technology for Ultrafine La3NbO7 Powder Prepared by Sol-Gel Process

2011 ◽  
Vol 412 ◽  
pp. 271-274
Author(s):  
Ying Li ◽  
Qiang Xu ◽  
Ling Dai
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Average Particle Size ◽  
Complex Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Acid Complex ◽  
Calcination Process ◽  
Sol Gel Process

In order to prepare ultrafine La3NbO7 powder, a potential material for thermal barrier coatings, the calcination process of La3NbO7 was studied in this paper.The precursor of La3NbO7 was synthesized by using a citric acid complex method. A calcination process had been systematically investigated. The reaction temperature was determined by differential scanning calorimetry (DSC). The phase composition of powders was characterized by X-ray diffraction (XRD), and the morphology was obtained by scanning electron microscope (SEM). The results revealed that the single-phase La3NbO7 powder could be successfully prepared while the calcination temperature exceeded 800°C and a better morphology could be maintained at 800°C for 4 hours. Considering all above, an optimum calcination scheme was adopted at 800°C for 4 hours. The as-prepared La3NbO7 powders had a grain size of about 50nm and an average particle size of about 300nm.

Effect of Hybrid Tackifiers on Viscosity, Peel Strength and Shear Resistance of Natural Rubber and Epoxidized Natural Rubber-Based Pressure Sensitive Adhesives

2015 ◽  
Vol 754-755 ◽  
pp. 49-53 ◽  
Author(s):  
Luqman Musa ◽  
Syed Zhafer Firdaus ◽  
Kamarudin Hussin ◽  
Poh Beng Teik
Keyword(s):  
Shear Strength ◽  
Natural Rubber ◽  
Shear Resistance ◽  
Peel Strength ◽  
Epoxidized Natural Rubber ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
Maximum Value ◽  
Gum Rosin ◽  
Peel Tests

Natural rubber (SMR L grade), epoxidized natural rubber (ENR) 25 and 50 were loaded with hybrid tackifiers consisting of a mixture of coumarone-indene and gum rosin. The coumarone-indene was fixed at 40 parts per hundred of rubber (phr) while the concentration of gum rosin was varied from 20 to 80 phr. The viscosity, peel and shear strength of the adhesives prepared from the elastomers was studied. Results show that peel strength exhibits a maximum value at 60 phr gum rosin for SMR L-based adhesive while for ENR 25 and ENR 50 based adhesives a maximum value is observed at 40 phr gum rosin which was attributed to the occurrence of optimum wettability and compatibility at this tackifier loading. Meanwhile, viscosity and shear strength decreases with increasing gum rosin concentration. SMR L-based adhesive consistently exhibits higher viscosity and shear strength whereas ENR 25-based adhesive steadily shows higher value for all modes of peel tests.

Melting Behavior in Granular Metal Thin Films

1990 ◽  
Vol 195 ◽  
Author(s):  
Karl M. Unruh ◽  
B.M. Patterson ◽  
S.I. Shah
Keyword(s):  
Particle Size ◽  
Melting Temperature ◽  
Average Particle Size ◽  
Melting Behavior ◽  
Multilayer Films ◽  
Relative Reduction ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Metal Thin Films ◽  
Solid Liquid

ABSTRACTGranular metal films consisting of small Sn, Bi, and Pb particles, typically from less than 100 Å to several 1000 Å in size and embedded in a SiO2 matrix, have been fabricated over a range of metal compositions by RF sputter deposition. Two different film geometries have been prepared, homogeneous films and multilayer films consisting of alternating layers of granular metal and SiO2. These films have been characterized by x-ray diffraction and transmission electron microscopy and their melting behavior studied by differential scanning calorimetry. As the concentration of the metal component is decreased, the average particle size decreases and the particle size distribution becomes more narrow. When the solid-liquid transition is studied, the melting temperature has been found to be increasingly depressed as the particle size is reduced. In the smallest particles the relative reduction in the melting temperature is greater than 10 percent. No strong evidence for melting point enhancements, due to pressureeffects arising from the different thermal expansions of the metal particles and the SiO2 matrix, has been observed in either the homogeneous or multilayer films.

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