Biodegradable Polyurethane Materials of Different Origin Based on Natural Components

Research Article

Austin J Biomed Eng. 2015; 2(1): 1030.

Biodegradable Polyurethane Materials of Different Origin Based on Natural Components

Savelyev YuV1, Travinskaya TV1*, Robota LP1, Markovskaya LA1, Akhranovich ER1, Brykova AN1, Savelyeva OA1, Furmanov YuA2 and Savitskaya IM2

1Department of Chemistry of Hetero chain Polymers and Interpenetrating Networks, Institute of Macromolecular Chemistry, Ukraine

2Department of Experimental Surgery, National Institute of Surgery and Transplantation named after A. Shalimov, Ukraine

*Corresponding author: Travinskaya TV, Department of Chemistry of Hetero chain Polymers and Interpenetrating Networks, Institute of Macromolecular Chemistry, NAS of Ukraine, Kharkovskoe shosse, 48, 02160, Kiev, Ukraine

Received: November 15, 2015; Accepted: December 30, 2015; Published: December 31, 2015


The “sustainable development” of environmentally efficient and harmless polymer materials is one of the most important tasks of the modern polymer chemistry. With an aim to develop environmentally friendly materials of wide range of applications, including (bio) medicine, we synthesized biodegradable polyurethanes of different nature: Ionic Polyurethanes (IPU) and Polyurethane Foams (PUF) based on renewable components of biotechnological exopolysaccharide Xanthan (Xa) and vegetable Castor Oil (CO). The comprehensive study of the “structure - properties - ability to (bio) degradation” relationship of structurally modified polymeric materials allows to make the conclusion, that due to incorporation of natural components into the polymer chain, the material acquires the property of biodegradation under environmental factors. The structure of the synthesized polymers has been proved by wideand small-angle X-rays scattering, infrared- and pyrolytic mass spectrometry. The biodegradability of synthesized polyurethane materials was confirmed by studies of the adhesion of microorganisms to their surface, by degree of hydrolysis in acid and alkali media and composting into a soil. Histological study of developed laboratory sample of composite material based on Xa containing PUF carried out on white mice has shown the complete resorption of the polyurethane component in the absence of injury and inflammation of the surrounding soft tissues.

Keywords: Ionic polyurethane; Polyurethane foam; Biodegradation; Natural components; Histological study


IPU: Ionic Polyurethane; PUF: Polyurethane Foam; Xa: Xanthan; CO: Castor Oil; POPG: Polyoxypropylene Glycol; ???G: Oligooxytetramethyleneglycol; P-503: Polyester, the condensation product of diethylene glycol, adipic acid and glycerol; TDI: Toluene Diisocyanate; HMDI: Hexamethylenediisocyanate; DMPA: Dimethylolpropionic Acid; TEA: Triethylamine; TO: Tin Octoate; UP-606/2: Tris-(dimethylamino-methyl)phenol; KEP-2: Blockcopolymer of polydimethylsiloxane and alkylene oxides; VO: Vaseline Oil; PP: Polypropylene; PTFE: Polytetrafluoroethylene; SAXS: Small- Angle X-ray Diffraction Scattering; WAXS: Wide- Angle X-ray Diffraction Scattering; PMS: Pyrolytic Mass Spectrometry; FTIR: Fourier Transform Infrared Spectroscopy; BS: Bacillus subtilis; MO: Microorganisms


One of the most important tasks of the modern international scientific community is the “sustainable development” of production of environmentally efficient and harmless materials today for the maintenance of “sustainable and green” tomorrow. One of the ways of this problem’s solution is the employment of renewable resources instead of fossil fuels, the use of clean technologies and the degradation of the materials after the end of their operation life. The concept revolves around the focal point of “green chemistry” or “chemistry of eco-friendly substances.” The materials used in biomedical purposes must be biocompatible and products of their degradation should not have a toxic effect on human body. This idea has already made its world debut in the form of environmentally friendly technologies, precluding the use of organic solvents, the use of water-based monomers/polymers, obtained from renewable resources. Vegetable oils, in particular, constitute the most rich, cost-effective, non-toxic biological resource of the nature [1,2]. For several years, they have traditionally been used as starting materials in the production of environmentally friendly biodegradable polymeric materials [3]. Today, the successes of biotechnology have provided widespread use of microbial polysaccharides (exopolysaccharides), which are often referred to as biopolymers. They are widely used in various fields of human activity. Some microbial polysaccharides are similar or even identical to plant or animal polysaccharides, but most of them have a unique structure, specific only for this type [4]. The most popularity has accrued the bacterial cellulose and Xanthan based products, extracellular polysaccharide of Xanthomonas Campestris bacterium. Microorganisms are cultivated in special bioreactors, which provide for them all the necessary conditions (nutrient medium, aeration or anaerobic conditions), temperature, pH, removal of metabolic products). The main chain of Xanthan is constructed similarly to cellulose (1-4-β-glycopyranosa) and in the branches there is trisaccharide consisting of β-D-mannose, β-D-glucuronic acid and a-D-mannose. Residues of glucuronic acid and acid pyruvic groups provide the xanthan molecules an anionic nature. Xanthan molecules are susceptible to self–association in aqueous solutions, and with an increase in ionic strength of solution or polysaccharide concentration the gel is formed which is a three-dimensional network formed from Xanthan double helices associated with intermolecular hydrogen bonds [5]. One of the areas of exopolysaccharides and vegetable oils use in the macromolecular chemistry is the development of (bio) degradable polymer materials of biomedical application on the basis of known synthetic polymers. Previously we have created polymers on the basis of the ionomeric polyurethanes and natural (poly) saccharides (alginate, starch, lactose, glucose, etc.), that degrade under the environmental factors, and comprehensively studied their structure and the effect of the natural component on the properties and propensity to (bio) degradation of polyurethane [6-9]. It has been proved that it is a chemical bond between synthetic and natural components plays a crucial role in giving to polymeric materials the ability to (bio) degradation in whole, unlike the mechanical mixtures, where with the lapse of time the only a natural component has degraded. The purpose of this work is the development of methods of synthesis and comprehensive study of the “structure - properties - ability to (bio) degradation” relationship of structurally modified polymeric materials based on different type of polyurethanes and renewable components of biotechnological (Xanthan) and vegetable (castor oil) nature and ability of their (bio) medical application.

Materials and Methods


Polyoxypropylene glycol POPG 5003 (MM 5000) - polyether on the basis of polyatomic alcohols and a copolymer of propylene and ethylene oxide. Hydroxyl number is about 32.0–36.0mg KOH/g. Acid number is not more than 0.10mg KOH/g (“Macro Oligooxytetramethyleneglycol; mer Ltd”, Russia). Oligooxytetramethyleneglycol ?? 1030 (???G-1000) (“Macromer Ltd”, Russia).

Polyester: P-503 (MM 500) is the condensation product of diethylene glycol, adipic acid and glycerol. Hydroxyl number is 280.0–330.0mg K??/g. The acid number is not more than 2.0 mg K??/g (“Corundum Ltd”, Russia).

Diisocyanate: Toluene Diisocyanate (TDI) is the mixture of 2,4 and 2,6-isomers (“Okakhim”, Russia), cleaned by vacuum distillation. Hexamethylenediisocyanate (HMDI) (“Okakhim”, Russia).

Dimethylolpropionic acid (DMPA) and Triethylamine (TEA) were purchased from Aldrich and used as received; Acetone (Fluka).

Catalysts: Tin Octoate (TO) (“Baltic manufacture”, Russia); tris-(dimethylamino-methyl) phenol (UP-606/2) (“Khimeks Ltd”, Russia).

Foam stabilizers: KEP-2 block-copolymer of polydimethylsiloxane and alkylene oxides (“Orgsintez”, Russia). Vaseline Oil (VO) (“Medkhim”, Russia).

Xanthan: (Xa) dry powder (Sigma, Xanthomonas camprestris pv camprestris (MM 2000000 - 50000000)).

Castor Oil: (CO) – triglyceride of ricinoleic acid (90%), linoleic and oleic acid (10%), hydroxyl number is about 150, Fluka, India.

Synthesis of polyurethane foam, sample of comparison (PUF-matrix)

Distilled water (0.42–3.00 wt.%), TO (0.53–2.07 wt.%), VO (0.11–0.4 wt.%), KEP-2 (0.73–1.53 wt.%), and UP-606/2 (0.37–1.53 wt.%) were charged at room temperature into the wide-necked flask equipped with a mechanical stirrer and all ingredients were mixed until a homogeneous mixture was formed. Then POPG-5003 (18.75– 52.65 wt.%) and ?-503 (4.18–19.1 wt.%) were added to the reaction mass under the stirring. After mixing and obtaining the homogeneous product (component I) the TDI (14.62–39.5) (component II) was added to the reaction mixture. The content of the flask was stirred until foam appearance (2–3 min), thereafter it was poured into the molds. Foam forming has occurred due to the release of carbon dioxide during the decomposition of unstable carbamic acid- the product of interaction of isocyanate groups with water.

Synthesis of CO/Xa based polyurethane foam

PUF, containing Xa / (50 % wt), PUF/Xa50; PUF, containing Xa (50 % wt), and CO (50 % wt), PUF/CO50/Xa50, where Xa was used in the native state (ns) and as a 15 % water gel (gel) have been prepared according to [10-12].

Polypropylene (PP) based mesh materials for hernioplasty with increased Xa content (70 % wt) PP/PUF/Xa70 were prepared as follows: PUF was obtained by mixing at room temperature (up to foaming - 60-100 sec.) of polyether component that is a mixture of POPG 5003 and P-503, catalysts TO and UP-606/2, foam stabilizers KEP-2 and VO and Xa – in native state with the isocyanate component TDI. The reaction mixture was poured on the PTFE form, rolled out in a thin layer and rolled on with polypropylene mesh.

Synthesis of ionic water dispersion, sample of comparison (IPU-matrix)

Preparation of IPU-matrix in the form of aqueous dispersion was achieved by the reaction of OTMG and HMDI based isocyanate precursor (component ratio 1:2, reaction time 2hours) with TEA neutralized DMPA, in acetone solution, followed by extension of anionic oligourethane prepolymer with water, dispersion and acetone removal.

Xa based ionomeric polyurethane dispersion (IPU/Xa) was produced analogously to IPU-matrix, except for Xa introduced into a precursor in the form of a dry powder in a stage of chain extension (content of Xanthan amounts 20% calculated with reference on dry substance) [13].

CO based ionomeric polyurethane dispersion (IPU/CO) was prepared by reaction of isocyanate precursor based on a mixture of OTMG, CO (wherein CO was added in an amount 20%) and HMDI in a molar ratio of 1:2, respectively (reaction time - 2hours, temperature – 80o C) with DMPA.

CO/Xa based ionomeric polyurethane dispersion (IPU/CO/ Xa)

In this case Xa was added as a dry powder to polyurethane precursor based on CO on the stage of chain extension sequentially after DMPA adding. Neutralization of the carboxyl groups of DMPA fragments was performed using TEA.

The general scheme of obtaining is as follows: