scholarly journals Adhesion and Energy Characteristics of Rigid-Chain Polymer Surface: Polyamidoimides

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2956
Author(s):  
Anatoly E. Chalykh ◽  
Valentina Yu. Stepanenko ◽  
Ali D. Aliev
Keyword(s):  
Packing Density ◽  
Monomer Unit ◽  
Polymer Surface ◽  
Surface Characteristics ◽  
High Energy ◽  
Contact Angles ◽  
Surface Layers ◽  
Adhesion Properties ◽  
Chain Polymer ◽  
Dispersion Component

The adhesion characteristics and surface energies of two series of polyamidoimides (PAI) with different molecular weights, monomer unit structures, hinge groups in the main chain of the macromolecules, and thermal prehistory were determined via delamination at 180° and test fluids contact angles. We found that PAI are high-energy polymers, the surface energy of which varies in the range from 32 to 45 mJ/m2. In contrast to flexible-chain polymers, the exponent in the McLeod equation is two, which is due to the flat parallel orientation of the macromolecular chains in the surface layers. The main contribution to the change in surface characteristics of these polymers is the change in the packing density of PAI macromolecules, which is reflected mainly in the change in the polymers’ dispersion component. We found that the adhesion properties of PAI with respect to high- and low-energy substrates are determined mainly by the macromolecules packing density in the surface layers with their conformation state unchanged.

scholarly journals The Use of Lasers in Dental Materials: A Review

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3370
Author(s):  
Emmanouil-George C. Tzanakakis ◽  
Evangelos Skoulas ◽  
Eudoxie Pepelassi ◽  
Petros Koidis ◽  
Ioannis G. Tzoutzas
Keyword(s):  
Energy Levels ◽  
Dental Materials ◽  
High Strength ◽  
Surface Characteristics ◽  
High Energy ◽  
Zirconia Ceramics ◽  
Material Management ◽  
Laboratory Procedures ◽  
Laser Devices ◽  
Exact Point

Lasers have been well integrated in clinical dentistry for the last two decades, providing clinical alternatives in the management of both soft and hard tissues with an expanding use in the field of dental materials. One of their main advantages is that they can deliver very low to very high concentrated power at an exact point on any substrate by all possible means. The aim of this review is to thoroughly analyze the use of lasers in the processing of dental materials and to enlighten the new trends in laser technology focused on dental material management. New approaches for the elaboration of dental materials that require high energy levels and delicate processing, such as metals, ceramics, and resins are provided, while time consuming laboratory procedures, such as cutting restorative materials, welding, and sintering are facilitated. In addition, surface characteristics of titanium alloys and high strength ceramics can be altered. Finally, the potential of lasers to increase the adhesion of zirconia ceramics to different substrates has been tested for all laser devices, including a new ultrafast generation of lasers.

scholarly journals The Use of Statistical Functions for the Selection of Laser Texturing Parameters

2020 ◽  
Vol 10 (1) ◽  
pp. 454-461
Author(s):  
Piotr Sęk
Keyword(s):  
Surface Texturing ◽  
Point Of View ◽  
Laser Surface Texturing ◽  
Machining Parameters ◽  
Textured Surfaces ◽  
Surface Layers ◽  
Adhesion Properties ◽  
Machine Elements ◽  
Selection Of ◽  
Statistical Functions

AbstractLaser surface texturing is currently the most developed technique for producing fully reproducible microcavities on the surfaces of machine elements. From the point of view of texture technology, an important aspect is the proper selection of process parameters to obtain texture elements with desirable and repetitive geometries and physicochemical properties. Surface texturing improves mottling and fretting resistance and is also used wherever the adhesion properties of surface layers (printing techniques, bonding materials, biological and chemical activity, coatings, etc.) are important. The article shows the possibility of applying statistical functions to the selection of appropriate machining parameters to obtain microgeometry useful in the application of textured surfaces [1].

Optical coherence tomography image analysis of polymer surface layers in sound-absorbing fibrous composite materials

2017 ◽  
Vol 63 ◽  
pp. 194-203 ◽  
Author(s):  
Eulalia Gliścińska ◽  
Dominik Sankowski ◽  
Izabella Krucińska ◽  
Jarosław Gocławski ◽  
Marina Michalak ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Image Analysis ◽  
Composite Materials ◽  
Fibrous Composite ◽  
Polymer Surface ◽  
Optical Coherence Tomography Image ◽  
Optical Coherence ◽  
Surface Layers ◽  
Tomography Image

scholarly journals Hydrophilicity Improvement of Polymer Surfaces Induced by Simultaneous Nuclear Transmutation and Oxidation Effects Using High-Energy and Low-Fluence Helium Ion Beam Irradiation

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2770
Author(s):  
Jung Woo Kim ◽  
Seung Hwa Yoo ◽  
Young Bae Kong ◽  
Sung Oh Cho ◽  
Eun Je Lee
Keyword(s):  
Surface Texture ◽  
Ion Irradiation ◽  
Ion Beam ◽  
High Energy ◽  
Contact Angles ◽  
Polymer Chains ◽  
Polymer Surfaces ◽  
Water Contact ◽  
Chemical Structures ◽  
Nuclear Transmutation

Two commodity polymers, polystyrene (PS) and high-density polyethylene (HDPE), were irradiated by high-energy He ion beams at low fluence to examine the wettability changes at different fluences. The water contact angles of the PS and HDPE surfaces were reduced from 78.3° to 46.7° and 81.5° to 58.5°, respectively, upon increasing the fluence from 0 to 1 × 1013 He2+/cm2 for irradiation durations ≤4 min. Surface analyses were performed to investigate these wettability changes. Surface texture evaluations via scanning electron and atomic force microscopies indicated non-remarkable changes by irradiation. However, the chemical structures of the irradiated polymer surfaces were notable. The high-energy He ions induced nuclear transmutation of C to N, leading to C–N bond formation in the polymer chains. Further, C–O and C=O bonds were formed during irradiation in air because of polymer oxidation. Finally, amide and ester groups were generated by irradiation. These polar groups improved hydrophilicity by increasing surface energies. Experiments with other polymers can further elucidate the correlation between polymer structure and surface wettability changes due to high-energy low-fluence He ion irradiation. This method can realize simple and effective utilization of commercial cyclotrons to tailor polymer surfaces without compromising surface texture and mechanical integrity.

scholarly journals Functionalization of Neutral Polypropylene by Using Low Pressure Plasma Treatment: Effects on Surface Characteristics and Adhesion Properties

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 202 ◽  
Author(s):  
Chiara Mandolfino ◽  
Enrico Lertora ◽  
Carla Gambaro ◽  
Marco Pizzorni
Keyword(s):  
Surface Morphology ◽  
Photoelectron Spectroscopy ◽  
Polymeric Materials ◽  
Low Pressure ◽  
Contact Angles ◽  
Bonded Joints ◽  
Water Contact ◽  
Adhesion Properties ◽  
Pressure Plasma ◽  
Low Pressure Plasma

Polyolefins are considered among the most difficult polymeric materials to treat because they have poor adhesive properties and high chemical barrier responses. In this paper, an in-depth study is reported for the low pressure plasma (LPP) treatment of neutral polypropylene to improve adhesion properties. Changes in wettability, chemical species, surface morphology and roughness of the polypropylene surfaces were evaluated by water contact angle measurement, X-ray photoelectron spectroscopy and, furthermore, atomic force microscopy (AFM). Finally, the bonded joints were subjected to tensile tests, in order to evaluate the practical effect of changes in adhesion properties. The results indicate that plasma is an effective treatment for the surface preparation of polypropylene for the creation of bonded joints: contact angles decreased significantly depending on the plasma-parameter setup, surface morphology was also found to vary with plasma power, exposure time and working gas.

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