Film materials with controlled release of biologically active substances

The properties of spun composites containing polyvinyl alcohol, a proteolytic enzyme (protease C or Terrilytin) and the high-molecular-weight antimicrobial polyhexamethyleneguanidine hydrochloride were investigated. The effect of the composition of the spinning compositions and spinning temperature on the properties of the film materials — the activity, stability, and rate of release of biologically active substances — was investigated. The possibility of obtaining polyvinyl alcohol films with controlled release of biologically active substances was demonstrated. Translated from Khimicheskie Volokna, pp. 44–48, September–October, 1998.     

Fabrication of modified fibre materials containing biologically active substances

The effect of the composition of a polymer composite used for treating unmodified textile material and the structure of the fibre matrix on the properties of the material obtained, which contains the proteolytic enzyme protease C and low-molecular-weight antimicrobial substances, was investigated. The factors that affect the biological activity and stability of biologically active fibre materials and the kinetics of separation of biologically active substance from them were established. The composition of the polymer composites which makes it possible to obtain fibre materials with long-lasting complex biological activity resistant to sterilization with γ-irradiation was determined. Translated from Khimicheskie Volokna, No. 6, pp. 15–21, November–December, 1997.     

Fabrication of Biologically Active Fibre Materials with Predetermined Properties

A method was developed for fabrication of fibre materials having a proteolytic and antimicrobial action with controlled drug release. A correlation was established between the composition of the polymer composite and the type of polymer matrix and the properties of the materials (activity, stability, kinetics of drug release). Moscow State Textile University. Translated fromKhimicheskie Volokna, No. 6, pp. 21–24, November–December, 2000.     

Development of cellulose textile materials containing chitosan and crab hepatopancreas proteolytic complex and study of their properties

The properties of unmodified crab hepatopancreas proteolytic complex and the complex immobilized on chitosan-containing cellulose substrates were investigated. The kinetics of immobilization and storage of dried preparations was investigated. Three stages ofinactivation of the immobilized sample were established: in immobilization, during drying and storage. It was shown that immobilization of the complex on a textile substrate protects enzymes from thermal inactivation in model buffer solutions at different pH. __________ Translated from Khimicheskie Volokna, No. 4, pp. 3–6, July–August, 2007.     

Synthesis and characterization of novel amphiphiles containing amino acid and carbohydrate

Amphiphiles composed of two different natural renewable raw materials, amino acid and carbohydrate (chitin), were synthesized, and their colloidal properties were studied. N-Higher acylated glutamic and aspartic acid were used as amino acid raw materials. Chitin monomer (N-acetyl glucosamine) and dimer (N,N′-diacetylchitobiose) were employed as the carbohydrate hydrophilic moiety in the amphiphiles. These surfactants showed a surface tension in the range of 30–36 mN/m at their critical micelle concentration. In the study of colloidal properties, such as surface tension, emulsification, and foaming, the surfactants containing the monosaccharide hydrophilic group showed much better results than those with disaccharide. Biodegradation measurements showed that the tested surfactants are biodegraded by environmental microorganisms to 57–73% of the initial levels in 14 d. Their biodegradation extent depended on neither the saccharide structure nor the kind of amino acid.     

Synthesis and characterization of novel comb-type amphiphilic graft copolymers containing polypropylene and polyethylene glycol

Amphiphilic comb-type graft copolymers containing polypropylene (PP) and polyethylene glycol (PEG) have been prepared. Polypropylene-g-polyethylene glycol comb-type thermoplastic amphiphilic copolymers were synthesized by the reaction between chlorinated polypropylene and polyethylene glycol in the presence of a base via a “grafting to” technique. A series of graft copolymers containing PEGs with molecular weights of 600 and 2,000 Da in the range of 4–34 mol% PEG were obtained. The amphiphilic graft copolymers with PEG segments in range between 20 and 30 mol% PEG displayed good film properties with elongation at break 275–440%. The hydrophilicity of the amphiphilic copolymers increases with the increasing PEG content in the copolymer while the mechanical properties decrease. Therefore, PP-g-PEG2000 with PEG contents in the range of 20–30 mol% PEG should be useful for medical and industrial applications where good film properties are needed.     

Fabrication of textile materials with a combined biological effect

Formation of a protease C—polyhexamethyleneguanidine hydrochloride polyelectrolyte complex was demonstrated by nephelometry and an analysis of the activity, stability, and physicochemical properties of immobilized protease C. The effect of the composition of the polymer composite used for modification of fibre polymer supports on the properties of the materials obtained was investigated. It was shown that cellulose and polyester fibre materials fabricated by the method developed and containing immobilized protease C and the high-molecular-weight antimicrobial polyhexamethyleneguanidine hydrochloride have prolonged enzyme and antimicrobial activity. Moscow State Textile Academy. Translated fromKhimicheskie Volokna, No. 2, pp. 8–11, March–April, 1999.     

Spinning of oxide fibres made of natural cellulose materials

The possibility of obtaining high-melting fibre materials from plant fibres and textile production wastes containing 40–60 wt. % cellulose was demonstrated. The optimum conditions of preliminary chemical treatment of natural raw material to increase the sorption capacity of the materials were determined. The conditions of heat treatment of salt-containing natural fibre materials which would allow regulating the crystal and pore structure of oxide fibres were established. Translated from Khimicheskie Volokna, No. 5, pp. 27–31, September–October, 1997.     

Structure and properties of orption-active nanocomposites from ultrahigh-molecular-weight polyethylene

The pore structure of filled films of ultrahigh-molecular-weight polyethylene fabricated by gel technology was investigated by IR spectroscopy and optical microscopy. The sorption capacity of films containing nanoparticles of zeolite and montmorillonite with respect to alkali and alkaline-earth metals was determined as a function of the degree of filling. __________ Translated from Khimicheskie Volokna, No. 2, pp. 33–37, March–April, 2007.     

Combustion synthesis of porous Ti-Co alloys for orthopedic applications

A mechanoactivation of Ti-Co mixtures was used to perform the SHS of Ti-Co alloys without preheating and heat-generating additives. The SHS of Ti-Co alloys from non-activated Ti + Co green mixtures containing an admixture of B₄C as a heat-generating agent without preliminary heating was carried out for the first time. The phase composition, structure, and mechanical properties of synthesized materials were explored upon variation in [B₄C] within the range 2–10 wt %. The desired structure/properties of combustion products were attained at [B₄C] = 2–4 wt %. The materials synthesized under the above optimal conditions exhibited a developed and uniformly distributed system of pores (largely open) with a size of 150–400 μm, at a wall thickness of 70–100 μm. By their properties (interconnected pores in the range 200–500 μm, compression strength 40–65 MPa), the synthesized materials can be recommended for use as metallic scaffolds intended for bone tissue ingrowths.      

Effect of the composition of flame retardant systems on the properties of viscose fibres

The possibility of modifying viscose fibre with hybrid systems containing flame retardants was demonstrated. The effect of the flame retardants on the physicomechanical properties of the fibres was determined. Bath compositions and modification parameters that ensure the sorption-diffusion reaction of the flame retardant and fibre and production of material with a high oxygen index (greater than 70%) were developed. Translated from Khimicheskie Volokna, No. 6, pp. 19–21, November–December, 2008.     

Synthesis and properties of water-soluble derivatives of chitin. A review

Concepts were formulated concerning the correlation of the structure and properties of an important class of biopolymers—aminopolysaccharides in aquatic organisms. Improved methods of obtaining water-soluble derivatives of chitin were developed, and their structure, physicochemical, and functional properties were characterized, including in the form of drugs, SF-PEC, and films. Moscow State Textile Academy. Translated fromKhimicheskie Volokna. No. 4, pp. 25–29, July–August, 1999.     

Step-Growth Polymerization of Poly(phenylcarbosilane) and Its Structural and Physical Properties

The polymerization and molecular weight distribution of poly(phenylcarbosilane) (PPCS) depend on the temperature and pressure conditions under which it is synthesized using the Kumada rearrangement reaction. Its degree of polymerization is related not only to its physical properties such as solubility and boiling point but also to its chemical structure. In this study, soluble PPCS having a weight-average molecular weight (Mw) in the range of 2,500–3,000 was selectively isolated through distillation or fractional precipitation, and its chemical structure and physical properties were studied via FT-IR, NMR, GPC, and thermal analysis. The analytical data indicate that the Si–CH₂–Si backbone and Si–Si bond are formed through step-growth polymerization and are clearly detected after purification. The differences in the thermal behavior of PPCS in air and in nitrogen were also investigated.     

Physicochemical properties of heterogeneous cellulose—solvent systems

The effect of low-molecular-weight liquids on the physicochemical properties of cellulose was investigated, the mechanical and chemical effects on the structure of cellulose were compared, and the reactivity of cellulose was investigated. The determining role of the system of hydrogen bonds and its structure in the reactivity of cellulose, which can be varied with chemical or mechanical effects, was demonstrated. __________ Translated from Khimicheskie Volokna, No. 4, pp. 49–59, July–August, 2006.     

Electrical studies of nanocomposites consisting of MWNTs and polystyrene

Multi-wall carbon nanotubes (MWNTs)/polystyrene (PS) nanocomposites containing different concentrations of MWNTs were prepared by the solution evaporation method. Dispersion of MWNTs in PS was achieved by using ultrasonic energy. The structure of nanocomposites was investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The dielectric constant (ε′), dielectric loss (ε″), and ac conductivity (σ _ac) were measured from room temperature to 100 °C over the frequency range 10³ Hz–1.2 MHz. The results show that the dielectric properties depend on both frequency and temperature and they are enhanced by increasing the MWNTs content.     

Characterization of polydimethylsiloxane–polyurethanes synthesized by graft or block copolymerizations

We synthesized polydimethylsiloxane–polyurethane dispersions modified with graft copolymerization (PDMS-G-PUDs) and polydimethylsiloxane–polyurethane dispersions modified with block copolymerization (PDMS-B-PUDs). We systematically investigated the effects of PDMS’s structure, content, and molecular weight on properties of copolymer including viscosity, particle size, and stability of dispersions as well as the properties of the film formed by dispersions including gloss, contact angle, water resistance, oil resistance, and mechanical properties. The results demonstrated that the viscosity, particle size, water resistance increased but gloss decreased with the increase of PDMS content and molecular weight. In addition, we compared the properties of PDMS-B-PUD films and PDMS-G-PUD films with the same amount of PDMS and similar molecular weight. PDMS-G-PUD films showed higher water and oil resistance, but lower gloss and poorer mechanical properties. Scanning electron microscopy–energy dispersive spectroscopy analysis (SEM–EDS) indicated that the films of PDMS-G-PUD had better microphase separation and PDMS surface enrichment.     

Study of the possibility of obtaining viscose fibre with biologically active properties by a continuous method

The effect of the composition of the polymer composite (type of polyhexamethyleneguanidine (PHMG) salt, content of components) on the structure of the composite formed and level of desorption of the biologically active substance (BAS) was established as a result of studying the kinetics of desorption of BAS from viscose fibres containing PHMG salt and polyalkylene oxide. The possibility of obtaining viscose fibres containing a biologically active substance of the polymer type with a continuous process scheme was demonstrated. __________ Translated from Khimicheskie Volokna, No. 4, pp. 44–47, July–August, 2007.     

Extrusion molding of kaolin sorbents

The properties of kaolin molding pastes containing modifying additives with different acid-basic properties were investigated. Addition of liquid glass significantly improves the structural-mechanical properties of the systems and increases the mechanical strength of the finished granulated sorbent. Preliminary modification of liquid glass with carbamides negatively affects the moldability of the kaolin pastes. Treatment of kaolin with acetic acid followed by dissolution of the paste with liquid glass decreases the extrudability; on the other hand, the volume of the open pores in the absorbent increases from 0.15–0.22 to 0.27–0.40 cm³/g. __________ Translated from Steklo i Keramika, No. 8, pp. 29–32, August, 2007.     

Development of technology for high-strength nonwoven materials

It was found that chemical fibres modified with organosilicon compounds have better physicomechanical properties than the initial fibres. The effect of the chemical structure and properties of the organosilicon compounds on the modification process and physicomechanical properties of the modified fibres was investigated. The optimum process parameters for manufacture of thermobonded nonwovens with elevated physicomechanical properties were determined. It was shown that treatment of the fibre web with a catalyst — hydrogen peroxide — allows eliminating the stage of heat treatment of the webs after application of the modifier which reduces the power consumed for production of nonwovens. __________ Translated from Khimicheskie Volokna, No. 2, pp. 21–23, March–April, 2006.     

Fibre materials based on ultrahigh-molecular-weight polyethylene and montmorillonite nanoparticles

The effect of the thermodynamic quality of the solvent on the properties of polymer solutions was determined. Thermal annealing affects formation of the structure and the mechanical properties of UHMPE. Fourier transform IR spectroscopy revealed the effect of the filler on the structure of the polymer matrix. The morphology of filled UHMPE fibres was characterized by optical microscopy; the fibres have a longitudinally oriented structure and the filler aggregates in particles up to 50 μm in size, which does not allow classifying the materials obtained as nanocomposites. Translated from Khimicheskie Volokna, No. 3, pp. 4–8, May–June, 2008.