**Acknowledgment**

The financial support of European Social Fund – "Cristofor I. Simionescu" Posdoctoral Fellowship Programme (ID POSTDRU/89/1.5/S/55216), Sectoral Operational Programme Human Resources Development 2007 – 2013 is acknowledged.

#### **5. References**

220 Polyurethane

device performance for this PU sample.

**Author details** 

**Acknowledgment** 

**4. Conclusions and further perspectives** 

The absence of GC and rich granulomatous tissue ingrowth through large material pores was observed for PU-PTHF/HPC sample (Fig.12, B-B2 images). Morphological aspect for PU-PTHF/HPC implant suggests a material-tissue integration and regenerative remodelling. Moreover, the fibroblast-rich tissue ingrowth only from one side of the membrane highlights the bifacial behavior of the implanted sample, with potentially tubular or cavity-like device performances. Thus, considering PU-PTHF/HPC increased haemocompatibility, oxidative and other biocompatibility advantages discussed above, we presume a cardiovascular-

Polyester and polyether urethane structures with improved bulk and surface characteristics by blending with small amount of biocompatible cellulose derivative, HPC, are screened for long-time functional integration. The stability of the pH value of biological media and the ratio of adsorbed albumin and fibrinogen from blood plasma were found to be the most valuable screening criteria to evaluate the blood-interface functionality, but not only. These criteria could provide information on material capacity to keep stability of the main body balances (oxidant/antioxidant, haemostasis/haemolysis) that are responsible for material acceptance in the early phase, followed by structural and functional integration in the later stages. These characteristics together with other important material properties as surface neutral charge and desired porous structure are keys points for good results expectance as was demonstrated. Another PU characteristic highlighted in our study was washability for potentially proinflammatory compounds removal. Due to interconnected mechanisms of thrombosis and inflammation, even haemocompatible PU, but with chronic prolonged inflammatory capacity (through itself or some released compound) will certainly get to fail its haemocompatibility *in vivo*. From this point of view we demonstrate an acceptable stability of some PU membrane by autoclaving and long-time watering in biological buffers. Further studies are necessary on extended classes of polyurethanes in the aim to prepare

and keep ready to use pre-equilibrated and safe PUs for medical applications.

Maria Butnaru, Ovidiu Bredetean, Cristina Daniela Dimitriu and Laura Knieling

The financial support of European Social Fund – "Cristofor I. Simionescu" Posdoctoral Fellowship Programme (ID POSTDRU/89/1.5/S/55216), Sectoral Operational Programme

Maria Butnaru, Doina Macocinsch and Valeria Harabagiu *"Petru Poni" Institute of Macromolecular Chemistry, Iasi, Romania* 

*"Grigore T. Popa " University of Medicine and Pharmacy, Iasi, Romania* 

Human Resources Development 2007 – 2013 is acknowledged.


Callahan, T.D. 4th, & Natale, A. (2008). Catheter Ablation of Atrial Fibrillation. *The Medical Clinics of North America,* Vol. 92, No.1, (Janury 2008), pp.179–201, ISSN 0025-7125

Biocompatibility and Biological Performance

of the Improved Polyurethane Membranes for Medical Applications 223

Gettens, R.T., Bai, Z., & Gilbert, J.L. (2005). Quantification of The Kinetics and Thermodynamics of Protein Adsorption Using Atomic Force Microscopy. *Journal of Biomedical Materials Research. Part A,* Vol. 72, No.3, (March 2005), pp. 246-257, ISSN 1549-

Gisselfa, K., Edberg, B., & Flodin, P. (2002). Synthesis and Properties of Degradable Poly(urethane urea)s To Be Used for Ligament Reconstructions. *Biomacromolecules,* Vol.

Gong, F., Lu, Y., Guo, H., Cheng, S., & Gao, Y. (2010). Hyaluronan Immobilized Polyurethane as a Blood Contacting Material. *International Journal of Polymer Science*,

Göpferich, A. (1996). Polymer Degradation and Erosion: Mechanisms and Applications. *European Journal of Pharmaceutics and Biopharmaceutics,* Vol. 42, No. 1, (1996), pp. 1–11,

Gray, J.J. (2004). The Interaction of Proteins With Solid Surfaces. *Current Opinion in Structural Biology*, Vol. 14, No.1, (February 2004), pp. 110–115, ISSN 0959-440X Guelcher, S., Srinivasan, A., Hafeman, A., Gallagher, K., Doctor, J., Khetan, S., Mcbride, S., & Hollinger, J. (2007). Synthesis, In Vitro Degradation, and Mechanical Properties of Two-Component Poly(Ester Urethane)Urea Scaffolds: Effects of Water and Polyol Composition. *Tissue Engineering*, Vol.13, No. 9, (September 2007), pp. 2321-2333, ISSN

Guelcher, S.A. (2008). Biodegradable Poliurethanes: Syntesis and Applications in Regenerative Medicine. *Tissue Engineering,* Vol. 14, No.1, (March 2008), pp. 3-17, ISSN

Gutowska, A., Jeong, B., & Jasionowski, M. (2001). Injectable Gels for Tissue Engineering. *The Anatomical Record,* Vol. 263, No.4, (August 2001), pp. 342–349, ISSN 0003-276X Hsu, H.S., Kao, Y.C., & Lin, Y.C. (2004). Enhanced Biocompatibility in Biostable Poly(carbonate)urethane. *Macromolecular Bioscience*, Vol.4, No. 4, (April 2004), pp. 464–

Huang, J., & Xu, W. (2010). Zwitterionic Monomer Graft Copolymerization Onto Polyurethane Surface Through a PEG Spacer. *Applied Surface Science,* Vol. 256, No. 12,

Hwang, S., & Meyerhoff, M.E. (2008). Polyurethane With Tethered Copper(II)ecyclen Complex: Preparation, Characterization and Catalytic Generation of Nitric Oxide from S-nitrosothiols. *Biomaterials,* Vol. 29, No. 16, (June 2008), pp. 2443-2452, ISSN 1552-4973 Jelinek, M., Kocourek, T., Remsa, J., Mikšovský, J., Zemek, J., Smetana, K. Jr., Dvořánková, B., & Luxbacher, T. (2010). Diamond/Graphite Content and Biocompatibility of DLC Films Fabricated by PLD. *Applied Physics A, Materials Science & Processing*, Vol. 110,

Jiang, W.W., Su, S.H., Eberhart, R.C., & Tang, L. (2007). Phagocyte Responses to Degradable Polymers. *Journal of Biomedical Materials Research. Part A,* Vol. 82, No. 2, (August 2007),

Jordan, S.W. & Chaikof, E.L. (2007). Novel Thromboresistant Materials. *Journal of Vascular* 

*Surgery*, Vol. 45, Suppl A, (June 2007), pp. 104A-115A, ISSN 0741-5214

3, No. 5, (September-October 2002), pp. 951-958, ISSN 1525-7797

Vol. 2010, Article ID 807935, (March 2010), pp.1-8, ISSN 1687-9422

3296

ISSN 0939-6411

1076-3279

2152-4947

470, ISSN 1616-5187

(April 2010), pp. 3921–3927, ISSN 0169-4332

No.4, (June 2010), pp.579-583, ISSN 0947-8396

pp. 492–497, ISSN 1549-3296


Gettens, R.T., Bai, Z., & Gilbert, J.L. (2005). Quantification of The Kinetics and Thermodynamics of Protein Adsorption Using Atomic Force Microscopy. *Journal of Biomedical Materials Research. Part A,* Vol. 72, No.3, (March 2005), pp. 246-257, ISSN 1549- 3296

222 Polyurethane

2010), pp. 157–168, ISSN 0003-9861

2004), pp. 245–255, ISSN 0021-9304

(June 2008), pp. 338-349, ISSN 1743-4297

382, ISSN 0160-564X

32657-X, Berlin, Germany

8305.

Vol. 45, (1994), pp.155–203, ISSN 0065-3233

Callahan, T.D. 4th, & Natale, A. (2008). Catheter Ablation of Atrial Fibrillation. *The Medical Clinics of North America,* Vol. 92, No.1, (Janury 2008), pp.179–201, ISSN 0025-7125 Cardinali, B., Profumo, A., Aprile, A., Byron, O., Morris, G., Harding, S.E., Stafford, W.F., & Rocco, M. (2010). Hydrodynamic and Mass Spectrometry Analysis of Nearly-Intact Human Fibrinogen, Chicken Fibrinogen, and of a Substantially Monodisperse Human Fibrinogen Fragment X. *Archives of Biochemistry and Biophysics,* Vol. 493, No. 2, (January

Carter, D.C. & Ho, J.X. (1994). Structure of Serum Albumin. *Advances in Protein Chemistry*

Chen, D., & Sun, B. (2000). New Tissue Engineering Material Copolymers of Derivatives of Cellulose and Lactide: Their Synthesis and Characterization. *Materials Science and* 

Chen, R., Huang, C., Ke, Q., He, C., Wang, H., & Mo, X. (2010). Preparation and Characterization of Coaxial Electrospun Thermoplastic Polyurethane/Collagen Compound Nanofibers for Tissue Engineering Applications. *Colloids and Surfaces B:* 

Christenson, E.M., Anderson, J.M., & Hiltner A. (2004). Oxidative Mechanisms of Poly(carbonate urethane) and Poly(ether urethane) Biodegradation: In Vivo and In Vitro Correlations. *Journal of Biomedical Materials Research*, Vol. 70A, No. 2, (August

Colman, R.W., & Schmaier, A.H. (1997). Contact System: A Vascular Biology Modulator With Anticoagulant, Profibrinolytic, Antiadhesive, and Proinflammatory Attributes.

Eberhart, R.C., Munro, M.S., Wiliams, G.B., Kulkarni, P.V., Shannon, W.A., Brink, B.E., & Fry, W.J. (1987). Albumin Adsorption and Retention on C18-alkyl-derivatized Polyurethane Vascular Grafts. *Artificial Organs,* Vol. 11, No. 5, (October 1987), pp. 375-

Edmunds, L.H.Jr . (1998). Inflammatory Response to Cardiopulmonary Bypass. *The Annals of* 

Förstermann, I. (2008). Oxidative Stress in Vascular Disease: Causes, Defense Mechanisms and Potential Therapies. *Nature Clinical Practice. Cardiovascular Medicine,* Vol. 5, No. 6,

Freeman, N. (2006). Analysis of the Structure at the Interface*,* In*: Proteins at Liquid – Solid Interfaces (Principle and practice)*, P. Dejardin, (Ed.), pp. 75-104, Springer, ISBN-10 3-540-

Fujimoto, K.L., Guan, J., Oshima, H., Sakai, T., & Wagner, W.R. (2007). In Vivo Evaluation of a Porous, Elastic, Biodegradable Patch for Reconstructive Cardiac Procedures. *The Annals of Thoracic Surgery*, Vol. 83, No. 2, (February 2007), pp. 648 –54, ISSN 0003-4975 Furie, B., & Furie, B.C. (2008). Mechanisms of Thrombus Formation. *The New England Journal* 

Gary, T. & Howard, G.T. (2002). Biodegradation of Polyurethane: A Review. *International Biodeterioration & Biodegradation,* Vol. 49, No. 4 (June 2002), pp. 245 – 252, ISSN 0964-

*of Medicine*, Vol. 359, (August 2008), pp. 938-949, ISSN 0028-4793

*Thoracic Surgery*, Vol. 66, No. 5, (November 1998), pp.12-16, ISSN 0003-4975

*Engineering: C*, Vol. 11, No. 1, (June 2000), pp. 57-60, ISSN 0928-4931

*Biointerfaces,* Vol. 79, No. 2, (September 2010), pp. 315–325, ISSN 0927-7765

*Blood*, Vol. 90, No. 10, (November 1997), pp 3819-3843, ISSN 0006-4971


Jun, H.W., Taite, L.J., & West, J.L. (2005). Nitric Oxide-Producing Polyurethanes. *Biomacromolecules*, Vol. 6, No. 2, (March-April 2005), pp. 838-844, ISSN 1525-7797

Biocompatibility and Biological Performance

of the Improved Polyurethane Membranes for Medical Applications 225

Lelah, M.D., & Cooper, J.L. (1987) *Polyurethanes in Medicine*, CRC Press, ISBN 0849363071,

Luxbacher, T. (2006). Electrokinetic Characterization of Flat Sheet Membranes by Streaming Current Measurement. *Desalination*, Vol. 199, (March 2006), pp. 376–377, ISSN 0011-9164 Macocinschi, D., Filip, D., Vlad, S., Cristea, M., & Butnaru, M. (2009). Segmented Biopolyurethanes for Medical Applications. *Journal of Materials Science: Materials in* 

Makala, U., Wood, L., Ohmanb, D.E., & Wynnea, K.J. (2006). Polyurethane Biocidal Polymeric Surface Modifiers. *Biomaterials*, Vol. 27, No. 8, (March 2006), pp. 1316–1326,

Marconi, W., Galloppa, A., Martellini, A., & Piozzi, A. (1996). New Polyurethane Compositions Able to Bond High Amounts of Both Albumin and Heparin. II: Copolymers and Polymer Blends. *Biomaterials*, Vol. 17, No. 18, (September 1996),

Marnett, L.J. (2002). Oxy radicals, Lipid Peroxidation and DNA Damage. *Toxicology*, Vol.

Michelsen, A.E., Santi, C., Holme, R., Lord, S.T., Simpson-Haidaris, P.J., Solum, N.O., Pedersen, T.M., & Brosstad, F. (2000). The Charge-Heterogeneity of Human Fibrinogen as Investigated by 2D Electrophoresis. *Thrombosis Research,* Vol. 100, No.6, (December

Morais, J.M., Papadimitrakopoulos, F., & Burgess, D.J. (2010). Biomaterials/Tissue Interactions: Possible Solutions to Overcome Foreign Body Response, *The AAPS Journal*,

Noinville, S., & Revault, M. (2006). Conformations of Proteins Adsorbed at Liquid–Solid Interfaces. In *Proteins at Liquid – Solid Interfaces (Principle and Practice),* P. Dejardin, (Ed.),

Oral, E., Rowella, S.L., & Muratoglu, O.K. (2006). The effect of α-Tocopherol on The Oxidation and Free Radical Decay in Irradiated UHMWPE. *Biomaterials*, Vol. 27, No. 32,

Ostuni, E., Chapman, R.G., Holmlin, R.E., Takayama, S., & Whitesides, G.M. (2001). A Survey of Structure –Property Relationships of Surfaces that Resist the Adsorption of Protein. *Langmuir: the ACS Journal of Surfaces and Colloids,* Vol. 17, No. 18, (September

Paradis, V., Kollinger, M., Fabre, M., Holstege, A., Poynard, T., & Bedossa, P. (1997). In Situ Detection of Lipid Peroxidation by-Products in Chronic Liver Diseases. *Hepatology,* Vol.

Parveen, N., Khan, A.A., Baskar, S., Habeeb, M.A., Babu, R., Abraham, S., Yoshioka, H., Mori, Y., & Mohammed, H.C. (2008). Intraperitoneal Transplantation of Hepatocytes Embedded in Thermoreversible Gelation Polymer (Mebiol Gel) in Acute Liver Failure

Rat Model. *Hepatitis Monthly,* Vol. 8, No.4, (2008), pp. 275-280, ISSN 1735-143X Pompe, T., Renner, L., & Werner, C. (2006). Fibronectin at Polymer Surfaces with Graduated Characteristics. In *Proteins at Liquid – Solid Interfaces (Principle and Practice),* P. Dejardin,

(Ed), pp. 175-198, Springer, ISBN-10 3-540-32657-X, Berlin, Germany

*Medicine*, Vol. 20, No. 8, (August 2009), pp. 1659–1668, ISSN 0957-4530

181-182, (December 2002), pp. 219-222, ISSN 0300-483X

June, Vol. 12, No. 2, (June 2010), pp. 188-196, ISSN 1550-7416

pp. 119-150, Springer, ISBN-10 3-540-32657-X, Berlin, Germany

(November 2006), pp. 5580–5587, ISSN 0142-9612

26, No. 1, (July 1997), pp. 135–142, ISSN 0270-9139

2001), pp. 5605–5620, ISSN 0743-7463

Boca Raton, Florida, U.S.A.

pp.1795-1802, ISSN 0142-9612

2000), pp. 529-535, ISSN 0049-3848

ISSN 1552-4973


Lelah, M.D., & Cooper, J.L. (1987) *Polyurethanes in Medicine*, CRC Press, ISBN 0849363071, Boca Raton, Florida, U.S.A.

224 Polyurethane

1742-7061

ISSN 0927-7765

0014-827X

0570-6963

0971-1198

pp. 247–259, ISSN 1549-3296

pp. 75–84, ISSN 0954-4119

Jun, H.W., Taite, L.J., & West, J.L. (2005). Nitric Oxide-Producing Polyurethanes. *Biomacromolecules*, Vol. 6, No. 2, (March-April 2005), pp. 838-844, ISSN 1525-7797 Kang, S., Hoek, E.M.V., Choi, H., & Shin, H. (2006). Effect of Membrane Surface Properties During the Fast Evaluation of Cell Attachment. *Separation Science and Technology*, Vol.

Kavlock, K.D., Pechar, T.W., Hollinger, J.O., Guelcher, S.A., & Goldstein, A.S. (2007). Synthesis and Characterization of Segmented Poly(esterurethane urea) Elastomers for Bone Tissue Engineering. *Acta Biomaterialia,* Vol. 3, No.4, (July 2007), pp. 475–484, ISSN

Keselowsky, B.G., Collard, D.M., & García, A.J. (2003). Surface Chemistry Modulates Fibronectin Conformation and Directs Integrin Binding and Specificity to Control Cell Adhesion. *Journal of Biomedical Materials Research Part A*, Vol. 66A, No. 2, (August 2003),

Khorasani, M.T., MoemenBellah, S., Mirzadeh, H., & Sadatnia, B. (2006). Effect of Surface Charge and Hydrophobicity of Polyurethanes and Silicone Rubbers on L929 Cells Response. *Colloids and Surfaces B: Biointerfaces,* Vol. 51, No. 2, (August 2006), pp.112–119,

Kirkpatrick, C.J., Bittinger, F., Wagner, M., Köhler, H., van Kooten, T.G., Klein, C.L., & Otto, M. (1998). Current trends in Biocompatibility Testing. *Proceedings of The Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine*, Vol. 212, No. 2, (1998),

Kouoh, F., Gressier, B., Luyckx, M., Brunet, C., Dine T., Cazin M., & Cazin, J.C. (1999). Antioxidant Properties of Albumin: Effect on Oxidative Metabolism of Human Neutrophil Granulocytes. *II Farmaco,* Vol. 54, No. 10, (October 1999), pp. 695-699, ISSN

Krieter, D.H., Steinke, J., Kerkhoff, M., Fink, E., Lemke, H.D., Zingler, C., Müller, G.A., & Schuff-Werner, P. (2005). Contact Activation in Low-Density Lipoprotein Apheresis Systems. *Artificial Organs*, Vol. 29, No.1, (January 2005), pp. 47-52, ISSN 0160-564X Kurrat, R., Prenosil, J. E., & Ramsden, J. J. (1997). Kinetics of Human and Bovine Serum Albumin Adsorption at Silica–Titania Surfaces. *Journal of Colloid and Interface science*,

Latour, R.A.Jr. (2008) Biomaterials: Protein–Surface Interactions. In: Encyclopedia of Biomaterials and Biomedical Engineering, Vol. 1, Wnek G.E., Bowlin G.L. (Ed.), pp. 270-

Lee, H., Cha, M.K., Kim, I.H. (2000). Activation of Thiol-Dependent Antioxidant Activity of Human Serum Albumin by Alkaline pH is Due to the B-like Conformational Change. *Archives of Biochemistry and Biophysics,* Vol. 380, No. 2, (August 2000), pp. 309-318, ISSN

Lee, J.S., Cho, Y.S, Lee, J.W, Kim, H.J., Pyun, D.J., Park, M.H., Yoon, T.R., Lee, H.J. & Kuroyanagy, Y., (2001). Preparation of Wound Dressing Using Hydrogel Polyurethane Foam. *Trends in Biomaterials & Artificial Organs,* Vol. 15, No. 1, (July 2001), pp. 4-6, ISSN

Vol. 185, No. 1 (January 1997), pp. 1-8, ISSN 0021-9797

285, Informa Healthcare, ISBN-10 1-4200-7953-0, New York, USA.

41, No. 7, (2006), pp. 1475–1487, ISSN 0149-6395


Rahman, I., van Schadewijk, A.A.M., Crowther, A.J., Hiemstra, P.S., Stolk, J., MacNee, W., & De Boer, W.I. (2002). 4-Hydroxy-2-Nonenal, a Specific Lipid Peroxidation Product, Is Elevated in Lungs of Patients with Chronic Obstructive Pulmonary Disease. American Journal of Respiratory and Critical Care Medicine*,* Vol. 166, No. 4, (August 2002), pp. 490-495, ISSN 1073-449X

Biocompatibility and Biological Performance

of the Improved Polyurethane Membranes for Medical Applications 227

Myocardial Repair. *Artificial Organs,* Vol. 31, No.6, (June 2007), pp. 425–433, ISSN 0160-

Song, M., Xia, H.S., Yao, K.J., & Hourston, D.J. (2005). A Study on Phase Morphology and Surface Properties of Polyurethane/Organoclay Nanocomposite. *European Polymer* 

Stachelek, S.J., Alferiev, I., Choi, H., Chan, C.W., Zubiate, B., Sacks, Composto, M.R., Chen, I.W., & Levy, R.J. (2006). Prevention of Oxidative Degradation of Polyurethane by Covalent Attachment of Di-Tert*-B*utylphenol Residues. *Journal of Biomedical Materials* 

Tribble, D.L., Aw, T.Y., & Jones, D.P. (1987). The Pathophysiological Significance of Lipid Peroxidation in Oxidative Cell Injury. *Hepatology,* Vol. 7, No. 2, (March-April 1987), pp.

Tsapikouni, T.S., & Missirlis, Y.F. (2007). pH and Ionic Strength Effect on Single Fibrinogen Molecule Adsorption on Mica Studied With AFM. *Colloids and Surfaces B: Biointerfaces,* 

Valenta, C., Auner, B.G. (2004). The Use of Polymers for Dermal and Transdermal Delivery. *European Journal of Pharmaceutics and Biopharmaceutics*,Vol. 58, No. 2, (September 2004),

Van Tassel, P.R. (2006). Protein Adsorption Kinetics: Influence of Substrate Electric Potential. In *Proteins at Liquid – Solid Interfaces (Principle and Practice),* P. Dejardin, (Ed.),

Verma, S., & Marsden, P.A. (2005). Nitric Oxide-Eluting Polyurethanes -- Vascular Grafts of the Future? *The New England Journal of Medicine,* Vol. 353, No. 7, (August 2005), pp. 730-

Vlad, S., Butnaru, M., Filip, D., Macocinschi, D., Nistor, A., Gradinaru L.M., & Ciobanu, C. (2010). Polyetherurethane Membranes Modified with Renewable Resource as a Potential Candidate for Biomedical Applications. *Digest Journal of Nanomaterials and Biostructures*, Vol. 5, No. 4, (October-December 2010), pp. 1089-1100, ISSN 1842 - 3582 Wahl, S.M., Wong, H., & McCartney-Francis, N. (1989). Role of Growth Factors in Inflammation and Repair. *Journal of Cellular Biochemistry,* Vol. 40, No. 2, (June 1989), pp.

Wan, L.S., Xu, Z.K., & Huang, X.J. (2006). Approaches to Protein Resistance on The Polyacrylonitrile-Based Membrane Surface: An Overview. In: *Proteins at Liquid – Solid Interfaces (Principle and Practice),* P. Dejardin, (Ed.), pp. 245-270, Springer, ISBN-10 3-540-

Wattamwar, P.P., Mo, Y., Wan, W., Palli, R., Zhang, Q., & Dziubla, T.D. (2010). Antioxidant Activity of Degradable Polymer Poly(trolox ester) to Suppress Oxidative Stress Injury in The Cells. *Advanced Functional Materials*, Vol. 20, No.1, (January 2010), pp. 147–154, ISSN

*Research. Part A*, Vol. 78, No. 4, (September 2006), pp. 653-661, ISSN 1549-3296 Sutherland, K., Mahoney, J.R., Coury, A.J, & Eatonil, J.W. (1993). Degradation of Biomaterials by Phagocyte-Derived Oxidants. *The Journal of Clinical Investigation*, Vol.

*Journal,* Vol. 41, No. 2, (April 2005), pp. 259–266, ISSN 0014-3057

92, No.5, (November 1993), pp. 2360-2367, ISSN 0021-9738

Vol. 57, No. 1, (May 2007), pp. 89–96, ISSN 0927-7765

pp. 1-22 , Springer, ISBN-10 3-540-32657-X, Berlin, Germany

564X

377–386, ISSN 0270-9139

pp. 279-289, ISSN 0939-6411

731, ISSN 0028-4793

193–199, ISSN 0730-2312

32657-X, Berlin, Germany

1616-301X


Myocardial Repair. *Artificial Organs,* Vol. 31, No.6, (June 2007), pp. 425–433, ISSN 0160- 564X

Song, M., Xia, H.S., Yao, K.J., & Hourston, D.J. (2005). A Study on Phase Morphology and Surface Properties of Polyurethane/Organoclay Nanocomposite. *European Polymer Journal,* Vol. 41, No. 2, (April 2005), pp. 259–266, ISSN 0014-3057

226 Polyurethane

490-495, ISSN 1073-449X

ISSN 0959-8103

2097, ISSN 0022-3042

ISSN 1389-2010

9304

2007), pp. 3904–3917, ISSN 0142-9612

Vol. 15, No. 4, (1994), pp. 287-292, ISSN 0267-6605

(July 2005), pp. 4351–4357, ISSN 0142-9612

Rahman, I., van Schadewijk, A.A.M., Crowther, A.J., Hiemstra, P.S., Stolk, J., MacNee, W., & De Boer, W.I. (2002). 4-Hydroxy-2-Nonenal, a Specific Lipid Peroxidation Product, Is Elevated in Lungs of Patients with Chronic Obstructive Pulmonary Disease. American Journal of Respiratory and Critical Care Medicine*,* Vol. 166, No. 4, (August 2002), pp.

Randrasana, S., Baquey, C.H., Delmond, B., Daudé, G., & Filliatre, C. (1994). Polyurethanes Grafted by Pendent Groups With Different Sizes and Functionality. *Clinical Materials,* 

Raschip, I.E., Vasile, C., & Macocinschi, D. (2009). Compatibility and Biocompatibility Study of New HPC/PU Blends. *Polymers International*, Vol. 58, No.1, (January 2009), pp. 4–16,

Ratner, B.D., & Bryant, S.J. (2004). Biomaterials: Where We Have Been and Where We Are Going. *AnnualReview of Biomedical Engineering,* Vol. 6, (2004), pp. 41–75, ISSN 1523-9829 Rezwan, K., Meiera, L.P., & Gauckler, L.J. (2005). Lysozyme and Bovine Serum Albumin Adsorption on Uncoated Silica and AlOOH-Coated Silica Particles: The Influence of Positively and Negatively Charged Oxide Surface Coatings. *Biomaterials*, Vol. 26, No. 21

Sanders, J.E., Lamont, S.E., Karchin, A., Golledge, S.L., & Ratner, B.D. (2005). Fibro-Porous Meshes Made From Polyurethane Micro-Fibers: Effects of Surface Charge on Tissue

Response. *Biomaterials*, Vol. 26, No. 7, (March 2005), pp. 813–818, ISSN 0142-9612 Sartori, S., Rechichi, A., Vozzi, G., D'Acunto, M., Heine, E., Giusti, P., & Ciardelli, G. (2008). Surface Modification of A Synthetic Polyurethane By Plasma Glow Discharge: Preparation and Characterization of Bioactive Monolayers. *Reactive & Functional* 

Sayre, L.M., Zelasko, D.A., Harris, P.L., Perry, G., Alomon, R.G., & Smith, M.A. (1997). 4- Hydroxynonenal-Derived Advanced Lipid Peroxidation End Products Are Increased in Alzheimer's Disease. *Journal of Neurochemistry,* Vol. 68, No. 5, (May 1997), pp. 2092–

Scott, E.A., & Elbert, D.L. (2007). Mass Spectrometric Mapping of Fibrinogen Conformations at Poly(Ethylene Terephthalate) Interfaces. *Biomaterials,* Vol. 28, No. 27, (September

Shastri, V.P. (2003). Non-Degradable Biocompatible Polymers In Medicine: Past, Present and Future. *Current Pharmaceutical Biotechnology*, Vol. 4, No. 5, (October 2003), pp. 331–337,

Shen, M., & Horbett, T.A. (2001). The Effects of Surface Chemistry and Adsorbed Proteins on Monocyte /Macrophage Adhesion to Chemically Modified Polystyrene Surfaces. *Journal of Biomedical Materials Research,* Vol. 57, No. 3, (December 2001), pp. 336–345, ISSN 0021-

Sieminski, A.L., & Gooch, K.J. (2000). Biomaterial–Microvasculature Interactions. *Biomaterials,* Vol. 21, No. 22, (November 2000), pp. 2232–2241, ISSN 0142-9612 Siepe, M., Giraud, M.N., Liljensten, E., Nydegger, U., Menasche, P., Carrel, T., & Tevaearai, HT. (2007). Construction of Skeletal Myoblast-Based Polyurethane Scaffolds for

*Polymers,* Vol. 68, No. 3 (March 2008), pp. 809–821, ISSN 1381-5148


Wertz, C.F., & Santore, M.M. (2001). Effect of Surface Hydrophobicity on Adsorption and Relaxation Kinetics of Albumin and Fibrinogen: Single-Species and Competitive Behavior. *Langmuir: The ACS Journal of Surfaces and Colloids,* Vol. 17, No. 10, (2001), pp. 3006-3016, ISSN 0743-7463

**Chapter 11** 

© 2012 Mahanta and Pathak, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Mahanta and Pathak, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

**HTPB-Polyurethane: A Versatile** 

Abhay K. Mahanta and Devendra D. Pathak

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/47995

**1. Introduction** 

**Fuel Binder for Composite Solid Propellant** 

One of the most promising applications of polyurethane (PU) polymers is as fuel-*cum*binder material in composite solid propellant. Since the last two decades, PU filled with oxidizer and metallic fuel is being widely used for rockets propulsion. Ariane boosters, shuttles Apogee motors, Peacekeeper (also called the MX-Missile Experimental) missile, Indian Augmented Satellite Launch Vehicle(ASLV) and Polar Satellite Launch Vehicle (PSLV) boosters are some of the motors that are fuelled by PU propellant. PU composite propellant (PCP) is a heterogeneous mixture of polymeric binder, inorganic oxidizer and metallic fuel as the major ingredients. It can be classified as a highly filled PU system in which the three dimensional elastomeric matrix binds the oxidizer and metallic fuel to form a rubbery material. It imparts necessary mechanical properties to the propellant grain to maintain its structural integrity. A PU propellant grain should have sufficient tensile strength and elongation to withstand various types of stresses experienced during handling and transportation, thermal cycling, sudden pressurization on ignition, and acceleration load during flight of the rocket motor. A tensile strength of approximately 7-8 kgf/cm2, an elongation of 40-50 % and initial modulus of 40-50 kgf/cm2 are reasonable for a typical case bonded rocket motor (Manjari et al., 1993). The PU binder accounts to 10-15 % of the composite propellant, and usually consists of three components: (1) a prepolymer (polyol), (2) an isocyanate curator, and (3) a chain extender (butan-1,4-diol) and cross-linking agent (trimethylol propane). The most commonly used polyol in recent time is the Hydroxyl Terminated Polybutadiene (HTPB). This liquid prepolymer has excellent physical properties such as low glass transition temperature, high tensile and tear strength, and good chemical resistance (Eroglu, 1998). The hydrocarbon nature of HTPB (98.6%) along with low viscosity (5000 mPas at 30 °C) and low specific gravity (0.90 g/cm3), makes it a promising fuel binder for PU propellant. It is capable of taking solid loading up to 86-88% without sacrificing the ease of processibility (Muthiah et al., 1992). In addition, it is also a major reducing agent and

