Hydroxyapatite/epoxy polymer composite for arthoplasty
I. C. F. Vaz1, F. González Garcia1,2, M. E. Leyva 2, A.A.A. de Queiroz2 and A. Z. Simões1,3
1
Labarotório de Química, Universidade Federal de Itajubá, Campus Itabira, MG, Brazil
2
Instituto de Ciências Exatas, Universidade Federal de Itajubá - UNIFEI, MG, Brazil
3
Departamento de Materiais e Tecnologia, Faculdade de Engenharia, Universidade Estadual
Paulista "Júlio de Mesquita Filho" Campus de Guaratingetá, UNESP , SP, Brazil
Total joint replacement (arthroplasty) is a common and very successful surgery for people
with degenerative arthritis (osteoarthritis) of the knee. Contemporary prosthesis for total hip
arthroplasty includes the use of high performance metallic prosthesis and a cement to promote
direct adhesion between the prosthesis and bone. Epoxy polymers have a wide range of
excellent physical, chemical and biological properties, which makes them essential for the
development of new technologies in biomaterials science. Depending on the chemical
structure of curing agents, it is possible to obtain toughness, chemical resistance, adhesive
strength properties ranging from extreme flexibility to high strength and hardness interesting
to the development of new adhesive formulations for use in arthroplasty. The high initial
adhesion properties of epoxy polymers to metallic surfaces make these materials interesting to
the development of bone cements for arthroplasty. The objective of this work was to evaluate
the adhesive strength of titanium/epoxy system /bone joints using different concentrations of
hydroxyapatite (HA) in the epoxy system. The epoxy system based on diglycidyl ether of
bisphenol-A (DGEBA; DER 331 from Dow Chemicals, Brazil), with an epoxide equivalent
weight equal to 187 g eq.-1 determined by chemical titration. It was carefully dehydrated
before use. The aliphatic amine epoxide hardener diethylenotriamine (DETA; from SigmaAldrich, 99 %, do Brazil S.A.), with amine hydrogen equivalent weight equal to 20,6 g eq-1
determined by potentiometric titration. The formulation was prepared by carefully weighing
the epoxy resin and aliphatic amine epoxide hardener at the stoichiometric amount (ratio
amino-hydrogen to epoxy, a/e = 1). The mixture was stirred for 1 minute at room temperature
to ensure hardener dissolution. Several samples were prepared with different concentration of
hydroxyapatite. All formulations were cured at room temperature for 24 h and after postcured at 130 °C for 2h. The influence of the hydroxyapatite concentrations in the epoxy
system on the adhesive strength titanium/epoxy system/bone joints was studied. Our work
resulted in a new cement with good adhesive strength suitable for the arthroplasty and it is
easy to manufacture and low cost compared with materials already used.
Key words: arthoplasty, hydroxyapatite, composites, adhesive strength, epoxy polymer.
Work supported.
[1] F. González Garcia et al./ J Appl Polym Sci 112, 1225 (2009).
[2] F. González Garcia et al./ Polímeros: Ciência e Tecnologia, 19, 177 (2009).
[3] F. González Garcia et al./ J Appl Polym Sci 106, 2047 (2007).
[4] F. González Garcia et al./ Polym Test 26, 95 (2007).
e-mail: [email protected] (I. C. F. Vaz)
Address: Rua São Paulo 377, Amazonas, CEP: 35900-373, Itabira – MG, Brazil