Enhancement Of Adhesion Properties Research Articles

Enhancement of adhesion properties between cement matrices and saturated substrates with asphalt mat by compatibilizing agents

Maintenance of construction elements is a necessary intervention action; preventive and corrective, which directly interferes with durability, lifetime performance. The same goes for reservoirs, where the waterproofing system makes it watertight, guaranteeing the potability of the stored water, an essential situation for the ideal conditions of an enterprise. The old projects have, mainly, waterproofing with asphalt blanket in their reservoirs, when entering the maintenance schedule to revitalize the waterproofing system, the companies adopt the application of cementitious waterproofing agents, such as Polymeric Mortar and Acrylic Polymer Membrane with cement, where they have chemical incompatibility that prevents good adherence to the substrate saturated with asphalt emulsion and asphalt mat traces. This work aims to determine the best method for creating bonding bridges between the standardized substrate covered with asphalt mat and the cementitious composite added with four different types of compatibilization agents applied in cement: sand: additive: water as 1:1:0.5:0 and 1:1:0.25:0.25. The additives are Epoxy primer for wet bases; Styrene-Butadiene emulsion (SBR); Vinyl copolymer and Acrylic-based emulsion. After curing, to guarantee the perforation of all applied layers in an integral and standardized way, three holes with an exact internal diameter were perforated for all the plates, with and without the agents, to perform the adhesive tensile test by a dynamometer. The results show that the adhesive strength of the asphalt mat on the substrate equals 0.2 MPa, limit of the related standard, was met by all plates. All mixtures showed an increase in the adhesion of the cementitious material to the asphalt mat, when the additive concentration is increased. Only plates with Vinyl-0.50, SBR-0.50, Acrylic-0.25 and Acrylic-0.50 registered average strengths greater than 0.50 MPa, the minimum requirement of the related standard, and higher than the REF plate by 36%, 16%, 22% and 56%, respectively. The rest of the plates failed. Therefore, the influence on the performance in the adhesion of the composite to the asphalt mat is directly linked to the type of compatibilizing agent, as well as its concentration.

Novel Hybrid Compound 4-[(E)-2-phenylethenesulfonamido]-N-hydroxybutanamide with Antimetastatic and Cytotoxic Action: Synthesis and Anticancer Screening.

One of the most promising strategies to develop multi-targeted anticancer therapeutics is to introduce to the structure of a potential drug two or more pharmacophores (functional groups or structural fragments), which have antiproliferative, proapoptotic or antimetastatic properties acting via different mechanisms. To design, synthesize and perform screening of a novel hybrid anticancer compound. A novel hybrid compound 4-[(E)-2-phenylethenesulfonamido]-N-hydroxybutanamide, combining butanehydroxamate and styrenesulfonamide moieties, was designed, synthesized and investigated as a potent antimetastatic and antiproliferative agent. The structure and purity of the synthesized compound were confirmed by 1H NMR, 13C NMR, LC/MS spectroscopy and elemental analysis. The compound was screened for the anticancer activity in vitro against HeLa and in vivo against Lewis lung carcinoma tumor, using an antitumor metalloenzyme inhibitor GM6001 (Ilomastat, Galardin) and Pifithrin-μ as control anticancer agents. It was found that the application of our compound resulted in a high fraction of apoptotic cells in the cell population, along with disruption in the cell cycle profile manifested as arrest of proliferative phases. Furthermore, changes of the morphological properties (i.e., an enhancement of adhesive properties and reduction of the nuclear-to-cytoplasm ratio) were found. The in vivo screening revealed that the compound significantly inhibited the metastasizing process that was manifested by a reduction in the number and volume of metastases. The obtained results demonstrate that our compound can serve as a base for further structure optimization in order to design new highly-effective antimetastatic and antitumor agents.

Enhancement of adhesive properties of road asphalts, waste oil processing products

In continuation of studies on the development of low-waste technologies for comprehensive utilization of oil production and refining waste, a method has been proposed for enhancement of the adhesive properties of secondary asphalt binders by introducing into their composition new amidoamine adhesive additives synthesized from soap stock, vegetable oil processing waste.

Coupled self-assembled monolayer for enhancement of Cu diffusion barrier and adhesion properties

In this work, we have demonstrated chemically coupled (3-aminopropyl)trimethoxysilane (APTMS) and 3-mercaptopropionic acid (MPA) self-assembled monolayers (SAMs) to enhance the diffusion barrier properties against copper (Cu) as well as the adhesion properties towards SiO2 and Cu electrode. The coupled-SAM (C-SAM) can attach to both Cu and SiO2 strongly which is expected to enhance both the diffusion barrier and adhesion properties. A carbodiimide-mediated amidation process was used to link NH2 terminated APTMS to COOH terminated MPA. The resulting C-SAM shows a low root-mean-square roughness of 0.44 nm and a thickness of 2 nm. Time-dependent dielectric breakdown (TDDB) tests are used to evaluate APTMS and C-SAM for their ability to block Cu ion diffusion. The average time-to-failure (TTF) is enhanced over 4 times after the MPA attachment, and is even comparable to TaN barriers. Capacitance–voltage (C–V) measurements are also conducted to monitor Cu ion diffusion. Negligible change in the flatband voltage and C–V curve is observed during the constant voltage stress C–V measurement. Enhancement of the adhesion properties are measured using four-point bending tests and shows that the C-SAM has a 33% enhancement in the adhesion properties between SiO2 and Cu compared to APTMS. The C-SAM shows potential as an ultra-thin Cu diffusion barrier which also has good adhesion properties.

Adhesion Between Rubber Compounds Containing Various Adhesion Promoters and Brass-Plated Steel Cords. Part II. Effect of Accelerator Loading in Rubber Compounds

The adhesion property between rubber compounds containing different types of adhesion promoters (resinous adhesion promoter (methylene donor/acceptor), cobalt salt and zinc borate) and loading amounts of accelerator and brass-plated steel cord was investigated to understand the effect of accelerator loading in rubber compounds on their adhesion characteristics to the brass-plated steel cords. The adhesion property of the rubber compounds to brass-plated steel cord was largely dependent on the type of adhesion promoter and the loading amount of accelerator in the rubber compounds. Among the various adhesion promoters incorporated, zinc borate showed the largest enhancement of adhesion properties after cure. For the rubber compounds containing zinc borate, pull-out force increased two times with increasing loading amount of accelerator from 0.4 to 1.6 phr. But for the rubber compounds containing either resinous adhesion promoter or cobalt salt, pull-out force decreased slightly with increasing loading amount of accelerator. For cobalt salt incorporated, interfacial failure between adhesion interphase and rubber compound after humidity aging occurs dominantly, whereas a cohesive failure occurs dominantly in the weak boundary layer closely adjacent to the adhesion interphase for both resinous adhesion promoter and zinc borate. Adhesion property was interpreted in terms of the interphases between the rubber compounds and the brass-plated steel cords studied using Auger electron spectroscopy. Suppression of dezincification was observed for a high loading of the accelerator in the rubber compounds.

Low-Temperature Plasma Treatment as an Effective Method for Surface Modification of Polymeric Materials

The specific features of the plasma modification process and its application area are considered. It is shown that this method is very effective for the enhancement of adhesive properties of a wide range of polymeric materials used in different fields of technology, as well as in the manufacture of membranes for different designations, including membranes for biological and medical purposes.