Organosilicon Polymers Research Articles

High-Temperature Resistant Polyborosilazanes with Tailored Structures.

Boron-containing organosilicon polymers are widely used under harsh environments as preceramic polymers for advanced ceramics fabrication. However, harmful chemicals released during synthesis and the complex synthesis routes have limited their applications. To solve the problems, a two-component route was adopted to synthesize cross-linked boron-containing silicone polymer (CPBCS) via a solventless process. The boron content and CPBCSs’ polymeric structures could be readily tuned through controlling the ratio of multifunctional boron hybrid silazane monomers (BSZ12) and poly[imino(methylsilylene)]. The CPBCSs showed high thermal stability and good mechanical properties. The CPBCS with Si-H/C=C ratio of 10:1 showed 75 wt% char yields at 1000 °C in argon, and the heat release capacity (HRC) and total heat release (THR) are determined to be 37.9 J/g K and 6.2 KJ/g, demonstrating high thermal stability and flame retardancy. The reduced modulus and hardness of CPBCS are 0.30 GPa and 2.32 GPa, respectively. The novel polysilazanes can be potentially used under harsh environments, such as high temperatures or fire hazards.

Синтез, сорбционные и металлохромные свойства кремнийорганических производных 1-ацетилгуанидина

Increased interest in carbofunctional organosilicon monomers (silanes) and polymers (silsesquioxanes) is associated with the fact that these compounds are promising reagents and building blocks, materials for micro-electronics, agriculture and medicine, complexones, catalysts, and efficient sorbents. Thus, functional polysilsesquioxanes surpass mineral and organic sorbents in sorption properties. Moreover, they have the highest chemical and thermal stability. Along with sorption activity carbofunctional organosilicon compounds of both monomeric and polymeric structures can possess metallochromic properties. All this paves the way for the large-scale development of analytical systems for the creation of new complex test methods for the determination, concentration and separation of metals from solutions. In the present study the functional monomer N-[3-(triethoxysilyl)propyl]acetylguanidine 1 was synthesized by the condensation reaction of 1-acetylguanidine and 3-triethoxysilyl-propylamine. Poly-N-[3-silsesquioxanyl) propyl]acetylguanidine 2 was obtained by hydrolytic polycondensation of compound 1. The composition and structure of compounds 1 and 2 were confirmed by IR and 1H NMR spectroscopy, as well as by elemental analysis. Polymer 2 was studied as a sorbent for ions of heavy metals, such as Hg (II), and noble metals Ag (I), Au (III), Rh (II), Pd (II), Pt (IV) from solutions of their salts in hydrochloric or nitric acid. For polymer 2, the values of static sorption capacities have been calculated. The latter depend on the nature of the metal and have values from 78 mg/g (for platinum) to 366 mg/g for rhodium. The graphs of the degree of metal extraction depending on the sorption time and acid concentration have been plotted. A sorption mechanism is proposed, which is realized due to the chelate interaction of the metal cation (M+) with the amide groups of compounds 1 and 2. The interaction of monomer 1, in the form of indicator paper, and polymer 2, in the powder form, with salts of the studied metals is accompanied by intense specific coloration (metallochromy). Color tables of the samples after their contact with the Ag (I), Au (III), Pd (II), Pt (IV), Rh (III), Hg (II) salts are given.

Quality control of parts which were manufactured from polymeric composite materials with hybrid matrix with the application of method of infrared thermography

This article contains the description of different polymer composite materials (PCM) with different types of hybrid matrices. One of the components of PCM’s hybrid matrix is hardened as the other one stays in its viscoelastic condition. The following materials are chosen to serve as viscoelastic components of hybrid matrix: technical wax compound, anaerobic and organosilicone polymer materials. The use of viscoelastic materials allows the enhancement of PCM’s stress-strain properties. This article also contains: the destruction mechanism of polymer composite materials with different types of hybrid matrices; the quality control process of products made of polymer composite materials with different types of hybrid matrices; the localization method of hybrid matrix viscoelastic components by using infrared thermography during product molding process. The results of quality control are shown as thermograms.

Biological evaluation of preceramic organosilicon polymers for various healthcare and biomedical engineering applications: A review.

Preceramic organosilicon materials combining the properties of a polymer and an inorganic ceramic phase are of great interest to scientists working in biomedical sciences. The interdisciplinary nature of organosilicon polymers and their molecular structures, as well as their diversity of applications have resulted in an unprecedented range of devices and synergies cutting across unrelated fields in medicine and engineering. Organosilicon materials, especially the polysiloxanes, have a long history of industrial and medical uses in many versatile aspects as they can be easily fabricated into complex-shaped products using a wide variety of computer-aided or polymer manufacturing techniques. Thus far, intensive research activities have been mainly devoted to the processing of preceramic organosilicon polymers toward magnetic, electronic, structural, optical, and not biological applications. Herein we present innovative research studies and recent developments of preceramic organosilicon polymers at the interface with biological systems, displaying the versatility and multi-functionality of these materials. This article reviews recent research on preceramic organosilicon polymers and corresponding composites for bone tissue regeneration and medical engineering implants, focusing on three particular topics: (a) surface modifications to create tailorable and bioactive surfaces with high corrosion resistance and improved biological properties; (b) biological evaluations for specific applications, such as in glaucoma drainage devices, orthopedic implants, bone tissue regeneration, wound dressing, drug delivery systems, and antibacterial activity; and (c) in vitro and in vivo studies for cytotoxicity, genotoxicity, and cell viability. The interest in organosilicon materials stems from the fact that a vast array of these materials have complementary attributes that, when integrated appropriately with functional fillers and carefully controlled conditions, could be exploited either as polymeric Si-based composites or as organosilicon polymer-derived Si-based ceramic composites to tailor and optimize properties of the Si-based materials for various proposed applications.

Recent progress in using hybrid silicon polymer composites for wastewater treatment

Heavy metal ions, oil and organic pollutants in water does not only cause serious water pollution, but also pose serious threats to ecosystems and human health. To this end, water pollution has gradually gained human attention, and various wastewater treatment methods are emerging. Organosilicon polymer composites are a class of materials that contain organic-inorganic hybrid structures with the characteristics of hydrophobicity, thermal stability and easy modification, which provides a brand new solution for wastewater treatment. In this review, various structural features including amorphous, linear, and cage structure of silicon containing polymer composites and the removal mechanism targeting at heavy metal ions, oil and organic pollutants of silicon containing polymer composites are summarized. The viewpoints and challenges in adsorption and engineering application are discussed, and possible solutions are proposed.

Solvent‐Free Synthesis of Selectively Wetting Multilayer and Janus Membranes

AbstractIn this work, the deposition of hydrophobic coatings onto porous materials is systematically studied for the fabrication of membranes with asymmetric and symmetric wetting properties. Initiated plasma‐enhanced chemical vapor deposition is used to deposit an organosilicon polymer coating onto chromatography paper of different thicknesses. The hydrophobic organosilicon polymer serves as an environmentally friendly alternative to fluorinated polymers and the all‐dry coating process does not use solvents. The deposition time, thickness of the paper, and orientation of the paper relative to the stage are shown to affect the symmetry of the wettability. The chemical functionality of the deposited polymer is characterized via Fourier‐transform infrared spectroscopy and X‐ray photoelectron spectroscopy. The hydrophobicity and wetting behavior of the coated paper are characterized with contact angle goniometry and wicking studies. Scale‐up of the process is also demonstrated by using a roll‐to‐roll module. The ability to systematically tune the wettability of materials allows for the fabrication of multilayer and Janus membranes for potential applications including filtration, smart textiles, flexible sensors, and wound dressings.

Thermal insulation materials based on polyurethane foam modified by the polymethylphenylsiloxane

In this work, the modification process of thermal insulation materials based on polyurethane foam by the organosilicon polymer polymethylphenylsiloxane was studied. The current state of thermal insulation materials based on polyurethanes problem and ways to improve the thermal and operational properties of foamed polyurethanes, such as maintaining the stability of characteristics under the influence of adverse factors, reducing moisture absorption and water absorption, were also analyzed. The influence of polymethylphenylsiloxane on the morphological characteristics and density of the resulting foams was studied. It was found that the introduced modifier affects the density of the resulting foam materials slightly. In this case, the introduction of an organosilicon product regardless of the ratio of the initial components leads to a decrease in water absorption. Studies have shown that the introduction of an organosilicon modifier in an amount of 2.5-5 m. h. leads to an increase in the heat resistance of the material. The heat resistance of modified samples increased by an average of 30-40 °C. Thus, the conducted research showed a real possibility of using the developed modified polyurethane foams for thermal insulation of industrial and civil objects.

Полиорганосилазаны: получение, свойства, применение

A review is given on the class of organosilicon compounds – polysilazanes. The review includes the history of the discovery of silazanes, the main chemical methods for producing silazanes, the main reactions taking place with the participation of silazanes, and the scope of application of silazanes. The review shows the composition of silazanes. The review consists of 40 literature sources. The synthesis of polyorganosilazanes was first described in 1964 by Kruger and Rohov. In the interaction of ammonia with chlorosilanes (ammonolysis), trimeric or tetrameric cyclosilazanes were formed at the beginning and in the subsequent reaction at high temperatures with a catalyst to obtain polymers with a higher molecular weight. Ammonolysis of chlorosilanes is still the most important synthetic route to polysilazanes. The industrial production of chlorosilanes using the Muller-Roch process, first reported in 1940, served as the cornerstone for the development of silazane chemistry. In the 1960s, the first attempts to turn organosilicon polymers into quasi-ceramic materials were described. At this time, suitable (“pre-ceramic”) polymers are heated to 1000 °C. or higher. It was shown that the elimination of organic groups and hydrogen leads to a rearrangement of the molecular network with the formation of amorphous inorganic materials, which show unique chemical and physical properties. Using polymer-derived ceramics, new applications can be discovered, especially in the field of high-strength materials.

Sodium 3-azidopropyldialkoxysilanolate - A versatile route towards new functional 1,2,3–triazole based hyperbranched polyorganoalkoxysiloxanes

A new type of hybrid organosilicone polymer combining the coordination ability of triazole rings with the advantages of the highly branched topological structure of the flexible polysiloxane backbone was synthesized, characterized and exploited for the formation and stabilization of silver nanoparticles.In this study a series of functional 3-azidopropylethoxysiloxanes and poly-1,2,3-triazoleorganoethoxysiloxanes with controlled molecular architectures were synthesized and characterized for the first time using controlled condensation of the new AB2-type sodiumoxo-3-azidopropyldiethoxysilane monomer and the Copper(I)-catalyzed azide-alkyne cycloaddition “Click chemistry” process. The new 1,2,3-triazole-based hybrid polymers with a functional hyperbranched polyethoxysiloxane polymer backbone showed the ability to stabilize ultrasmall silver nanoparticles.The synthesized structures were characterized using 29Si NMR, 1H NMR, FTIR, Mass-spectrometry, and GPC. Polymer nanocomposites with the stabilized silver nanoparticles were characterized by transmission electron microscopy (TEM).

Electrical Resistance of Polymeric Compounds Filled with SHS-Produced TiC–Al2O3 Powders

SHS-produced TiC–Al2O3 powders were used as a filler of organosilicon polymers and ethoxyline resin to prepare electroconducting polymeric compounds. The electrical conductivity of thus prepared polymeric compounds was found to depend on the amount of added ceramic powder, temperature, and type of polymer binder. A threshold effect observed for the temperature dependence of compound resistance can be used in designing temperature sensors and temperature/current-limiting devices. Our polymeric compounds can also be recommended as a material for film heaters with a working temperature of below 300°С.

Thioether‐Facilitated Iridium‐Catalyzed Hydrosilylation of Steric 1,1‐Disubstituted Olefins

One facile and efficient strategy for the hydrosilylation of steric 1,1‐disubstituted terminal alkenes is demonstrated. Investigations on substrate scope and control experiments revealed the necessity of thioether in promoting this process under a simple iridium catalytic system. This convenient and feasible method is expected to be useful in the synthesis of sulfur‐containing organosilicon polymers with different side‐chains.

The Influence of Nanocomposite Composition on Conductive and Hydrophobic Characteristics of Coatings

The influence of composition of nanocomposites composed of a polymer matrix and a functional nanofiller—carbon nanotubes (CNTs)—on the conductive, hydrophobic, water-repellent, and adhesive properties of relevant coatings is studied in this work. Coatings based on organofluorine and organosilicon matrices were produced using native CNTs and CNTs functionalized by the alkyl groups. To elucidate the effect of composition of a coating on its functional properties, both the filler concentration at a constant matrix content and the matrix concentration at a constant amount of CNTs were varied. It is found that the surface resistance of coating with a CNT content of 10 to 20% when using the organofluorine matrix is much higher (from 272.5 to 16.07 Ω kV–1) than for coatings based on the organosilicon polymer (from 17.52 to 11.15 Ω kV–1). Probing the relief and structure of coatings reveals that self-organization of carbon nanotubes in a polymer allows one to achieve the surface roughness at both the macro- and nanoscales, increasing the edge angle of surface wetting by water from 92.5° to 135.8° for samples based on the organofluorine polymer and from 113.5° to 144° for samples with the organosilicon matrix. The water drop roll-off angles of these coatings cover a range from 60.2° to 1°.

КЕРАМИКА НА ОСНОВЕ КРЕМНИЙОРГАНИЧЕСКИХ ПОЛИМЕРОВ-ПРЕКУРСОРОВ: СПОСОБЫ ПОЛУЧЕНИЯ И СВОЙСТВА (обзор)

The main types of preceramic organosilicon polymers, general methods of their synthesis and physical, and chemical properties are considered. Methods of shaping, curing and pyrolysis of polymers and the influence of process parameters on the composition, structure and properties of ceramics are described. Separately, the work considers modifying fillers for preceramic polymers, the goals and methods of their introduction into the polymer, the features of processing the compositions and the properties of the products obtained.

A comprehensive review on synthesis, characterization, and applications of polydimethylsiloxane and copolymers

Polydimethylsiloxane belongs to a polymeric organosilicon compounds that is widely used as silicon-based organic polymer. Polydimethylsiloxane is a basically optically clear, inert, nontoxic and inflammable material which is widely used in medical devices, as an elastomer, antifoaming agent, heat-resistant lubricants, fire retardants, in cosmetics and for other valuable domestic applications. This comprehensive review of polydimethylsiloxane describes synthesis, characterization, surface modifications and formation of vital biodegradable films/membranes that can facilitate improvements in modern research. Polydimethylsiloxane is viscoelastic, hydrophobic, cytocompatible and herbicidal penetrant that provides water-repellent coatings in textile industry. In this study, copolymers of polydimethylsiloxane were thoroughly studied based on polyimides, carboxyesters, hydroxyethyleneoxide, degradation with polystyrene, cross-linking with block copolymers, phosphorus-based, gelatin-based and polyurethanes, which can be used for modern manufacturing purposes in all kinds of industrial world.

A novel film-forming silicone polymer as shale inhibitor for water-based drilling fluids

AbstractA novel shale inhibitor was synthesized by free radical copolymerization in aqueous solution, using acrylic acid (AA), acrylamide (AM), maleic anhydride (MA) KH-570 as reaction monomers and potassium persulfate as initiator. The structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) showed that the thermal decomposition temperature of the copolymer was higher than 226°C, which indicated that the copolymer had good high temperature resistance. At the same time, the inhibition performance of the copolymer was further evaluated by linear expansion, immersion test and rolling recovery. The experimental results show that the inhibition performance of organosilicon polymer is obviously better than that of potassium chloride (KCl) and potassium polyacrylate (KPAM), and it can be used as an inhibitor in shale gas drilling.

A Foreword from the Editor-in-Chief

Accompanying the development of petrochemical industry, great progress has been achieved in the organic polymer materials. It is well known that the conventional polymer materials usually consist of organosilicon polymers, polycarbonates, polyethylene, polyamide, polyurethane, polysulfone, phenolic resin and so on. Although their synthesis and applications have been well developed, the further research on them still has great significance. Moreover, natural polymers such as polysaccharides, tannins, cellulose also occupy an important position in the family of the organic polymer materials.

The effect of crosslinking conditions on the dynamic viscosity of organosilicon polymers

The effect of crosslinking conditions on the dynamic viscosity of organosilicon polymers

The Effect of the Storage Time of Polymeric Composite Ingredients Based on Liquid Organosilicon Polymers Exerted on Vulcanization Kinetics

Formation kinetics is studied for the spatial structure in a low-molecular grafted organosilicon copolymer during vulcanization with the use of an amine-type cold-hardening catalytic system. The structurization of the organosilicon copolymer has been studied depending on the storage time of the catalytic system and that of the polymer. Methodological approaches to the interpretation of the vulcanization kinetic curves for organosilicon copolymer are presented. It is established that the storage time of the catalytic system determines the choice of the catalyst content required for achieving a preset structurization level of polymeric composites.

Plasma CVD/etching of Poly(methyl methacrylate) surface: optical and structural characterizations

Poly (methyl methacrylate) (PMMA) optical polymer surface has been treated in a RF remote plasma system, in three different plasma environments. Firstly, its surface has been coated with a plasma polymerized organosilicon precursor (Hexamethyldisilazane: HMDSN), secondly, PMMA surface has been exposed to oxygen plasma, and thirdly SF6 plasma has been used to treatment PMMA surface. The impact of plasma treatment on PMMA surface properties has been monitored using different characterizations techniques: optical reflectance, wettability by using water contact angle measurement, surface morphology using atomic force microscopy (AFM) and chemical structure using attenuated total reflectance of Fourier transformer infrared spectroscopy (ATR-FTIR). The correlations between the different properties have been discussed. The results revealed the possibility of tuning the optical and wetting PMMA surface properties by plasma surface treatment, according to the induced changes in surface morphology and chemical structure after plasma treatment. Particular interesting results are lowest reflectance after PMMA surface O2 plasma exposure and high hydrophobic surface obtained after SF6 plasma surface treatment.

Microrobot‐in‐glass for dynamic motion analysis and wider in vitro applications

Microrobots could become a key enabler in life science and medicine research as well as industrial applications. Although they provide high-performance tools for a wide range of applications, their environment and particularly surface forces induce significant challenge for their control. This work introduces an originally integrated microrobot in a permanently sealed glass microfluidic chip. Compared to conventional polymer chips, the glass substrate offers a smooth, stable, and inert surface. It also avoids the typical contamination and fast degradation of organosilicon polymers. In this environment, they demonstrate high-frequency hydrodynamics analysis and control. This strategy offers a high precision platform to study microrobot design and hydrodynamics as well as a transducer module for mapping surfaces and sensing interaction with physical environments.