SYNTHESIS OF AMINE-CONTAINING SURFACES IN POLY(TETRAFLUOROETHYLENE) BY GAMMA RADIATION

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1 SYNTHESIS OF AMINE-CONTAINING SURFACES IN POLY(TETRAFLUOROETHYLENE) BY GAMMA RADIATION Guillermina Burillo, Adan Hezael, Juan Carlos Ruiz B. Evelyne Kasparek, Alejandra Ortega, Lorena Garcia- Uriostegui and Pierre-Luc Girard-Lauriau. Instituto de Ciencias Nucleares UNAM

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3 Introduction Cell Attachment on surfaces and cell adhesion are critical for biomedical and biotechnological applications like the development of biomaterials for tissue engineering. Primary amine grafting polymers can be useful surfaces for cell colonization, they are usually prepared by plasma polymerization of alkyl amine monomers. But in a plasma reaction, there is considerable fragmentation of the original compound and a wide range of different functional groups are incorporated in the system, and the entrapment of radicals into plasma polymers leads to the reactive incorporation of oxygen on subsequent exposure to air. Primary amine groups decrease with time.

4 Objectives -The synthesis of a new system of PTFE modified to obtain high amount of primary amines in the surface by gamma radiation. The synthesis include the grafting of acryloylchloride (AC) onto PTFE, their amination with ethylenediamine (ED) and their characterization by XPS in derivatized samples, SEM, FTIR, TGA and contact angle. - The study of the decay of amine primary groups. - The study of adhesion cellular with

5 Synthesis Amine containing surfaces in poly(tetrafluoroethylene) (PTFE) was obtained in two steps. First step. Grafting of acryloylchloride by gamma radiation a) grafting by radiation direct method. b) preirradiation peroxidation grafting method Second step. Reaction with diethyldiamine. The effects of the monomer concentration, absorbed dose, and reaction time.

6 scheme

7 Results Grafting percentage of AC esterified with methanol, as as a function of dose: monomer concentration: 5 %; 3 % Grafting percentage of AC esterified with methanol, as a function of the monomer concentration. Dose 2 kgy.

8 Characterization TGTGA of a) PTFE; b) PTFE-g-AC esterified witwith MeOH; c) PTFE-g-AC reacted with diamine; d) derivatized with TFBA FTIR of a) PTFE; ; b) PTFE-g-AC esterified with MeOH; c) reacted with amine; d) derivatized with TFBA

9 a b c d e f SEM micrographs of: a) and d) surface and edge of PTFE films; b) and (e) PTFE-g-AC esterified with MeOH; c) and f) PTFE-g- AC reacted with ED.

10 No. Theta(M)[ deg] Theta(L)[ deg] Theta(R)[ deg] ± ± ± average No Theta(M)[d eg] Theta(L)[d eg] Theta(R)[d eg] 11.1 ± ± ± ± average PTFE PTFE-g-ED (3%)

11 Cl2p Si2p Si2p N1s Ca2p C1s N1s Ca2p C1s C1s O1s Na1s F1s F1s Si2p C1s O1s F1s B) * F C F C n * F H CH 2 C m * C O O CH C H 1 C) * F C F F C n * CH 2 CH H 2 C m p * C O C O O NH CH 3 CH 2 CH 2 2 D) * F C F H F C CH 2 C CH H m 2 C p * n * C O C O O NH CH 3 CH 2 CH 2 N C H CF 3 8 NH

12 Elemental quantification of samples by XPS. Elemental Composition (at. %) C1s F1s O1s N1s Si2p Ca2p Na1s a) PTFE 32.6 ± ± ± b) PTFE-g-MA 39.9 ± ± ± ± c) PTFE-g-EAAm 37.9 ± ± ± ± ± d) PTFE-g-EAAm +TFBA 48.3 ± ± ± ± ± ± ±.1

13 a) C-C b b) C-OR c) C=O d) CH 2 -CF 2 e)cf 2 -CF 2 e A) C1s A) F1s A) O1s d c b a a) C-C b) -COOC,C-NH 2 c) C-OR d) C=O, O=C-N e)coor f) CF 2 -CF 2 c b a C) C1s C) F1s 45 a) O=C b) O-C b a C) O1s 1 f e d a) C-C D) C1s a b) b-cooc,c-nh 2 b 6 c) C-OR d) C=O, O=C-N e) COOR 5 f) CF C) F1s 1 a) O=C b) O-C C) O1s 4 g) CF g f e d c

14 Conclusions Modification of PTFE surface to have primary amines was obtained in two steps, irradiation grafting of AC and further reaction with ethylendiamine. Surface characterization was performed with different techniques like FTIR; DSC; TGA, SEM and quantitative amount of primary amines was realized by derivatization with TFBA and characterization with XPS. A grafting percentage of AC was choosing between 2-3%, because only a modification surface was necessary for adhesion cellular. But grafting in bulk was obtained at this range of grafting percentage, as can be seen by SEM characterization. Aminated-PTFE films with grafting of 26 %, presented a primary amine concentration of 3.5 at. %, studied by XPS chemical derivatization, which make them suitable surfaces for different biomedical application.

15 Acknowledgements The authors thanks to Luz Maria Moya, Luis Miguel Valdez and Francisco Martinez for technical assistance and to PAPIIT UNAM, project IN2116 for financial support.

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17 Thanks for your attention