A research work done by Dr. Hesham El-Maghraby, hf_elmaghraby@yahoo.com

1. A Study on Constitution and Properties of Gypsum-Polymer Composites Author: Hesham Abdel Rehim, MSc. Supervisor: Assoc. Prof., RNDr. Ondrej Gedeon, Ph.D.

3. Dehydration: CaSO 4 .2H 2 O + Energy -> CaSO 4 .½H 2 O + 1½ H 2 O CaSO 4 .½H 2 O + Energy ->  -CaSO 4 + ½H 2 O Gypsum Technology Rehydration: CaSO 4 .½ H 2 O+ 1½H 2 O -> CaSO 4 .2H 2 O + Energy

6. Vinyl-based polymers PVA P(VA-co-VAc-co-It) P(VC-co-VAc-co-VA) [ CH 2 CH ] n OH CH 2 COOH [ CH 2 CH ] x [ CH 2 CH ] y [ CH 2 C ] z OH COOCH 3 COOH [ CH 2 CH ] x [ CH 2 CH ] y [ CH 2 CH ] z Cl COOCH 3 OH

7. 1. Assessment of the starting materials (Plaster & polymers). 2. Formation of different polymer/plaster composites. 3. Measuring of the mechanical properties. 4. Correlation with the microstructure. 5. Studying of the bioactivity of gypsum and gypsum- polymer composites. Experimental Work

9. PVA/plaster composites Mechanical properties --- --- --- 19.5 ± 0.7 16.1 ± 0.3 7.6 ± 0.3 4.0 --- --- --- 22.0 ± 0.6 17.5 ± 0.4 8.6 ± 0.6 3.0 11.9 ± 0.4 10.4 ± 0.2 4.1 ± 0.1 22.8 ± 0.7 19.6 ± 1.2 9.2 ± 0.6 2.0 14.5 ± 0.2 13.1 ± 0.2 4.9 ± 0.1 28.5 ± 0.1 28.4 ± 0.4 12.9 ± 0.4 1.0 11.3 ± 0.2 10.8 ± 0.2 4.5 ± 0.1 25.0 ± 0.3 23.2 ± 1.0 10.9 ± 0.5 0.5 --- --- --- 22.2 ± 0.7 18.7 ± 0.8 10.8 ± 0.6 0.25 8.7 ± 0.2 6.7 ± 0.2 2.3 ± 0.2 18.2 ± 0.2 17.7 ± 0.2 8.5 ± 0.2 0.00 7 Days 3 Days One Day 7 Days 3 Days One Day Bending Strength (MPa) Compressive Strength (MPa) Polymer/plaster wt. %

10. PVA/plaster composites 1- Compressive strength with aging time 2- Compressive strength with polymer concentration

11. PVA/plaster composites Microstructure

12. P(VA-co-VAc-co-It)/plaster composites Mechanical properties --- --- --- 19.1 ± 0.11 17.9 ± 0.07 8.0 ± 0.05 2.0 --- --- --- 20.9 ± 0.06 19.9 ± 0.08 9.1 ± 0.05 1.6 8.7 ± 0.11 6.7 ± 0.06 2.9 ± 0.09 21.4 ± 0.11 20.4 ± 0.13 9.3 ± 0.06 1.4 9.2 ± 0.08 7.1 ± 0.05 3.1 ± 0.09 23.2 ± 0.25 23.1 ± 0.00 10.4 ± 0.07 1.2 8.6 ± 0.11 6.4 ± 0.08 2.4 ± 0.05 22.3 ± 0.11 21.6 ± 0.09 10.1 ± 0.06 1.0 --- --- --- 21.7 ± 0.05 20.7 ± 0.11 9.9 ± 0.07 0.8 --- --- --- 21.5 ± 0.09 20.2 ± 0.05 9.5 ± 0.16 0.6 --- --- --- 20.8 ± 0.08 19.9 ± 0.15 9.2 ± 0.11 0.4 --- --- --- 19.7 ± 0.10 19.2 ± 0.14 8.8 ± 0.05 0.2 8.7 ± 0.23 6.7 ± 0.19 2.3 ± 0.16 18.2 ± 0.16 17.7 ± 0.18 8.5 ± 0.21 0.0 7 Days 3 Days One Day 7 Days 3 Days One Day Bending Strength (MPa) Compressive Strength (MPa) Polymer wt. %

13. P(VA-co-VAc-co-It)/plaster composites 1- Compressive strength with aging time 2- Compressive strength with polymer concentration

14. P(VA-co-VAc-co-It)/plaster composites Microstructure Neat plaster 2.0 wt. % 1.2 wt. %

15. P(VC-co-VAc-co-VA)/plaster composites Mechanical properties --- --- --- 17.7 ± 0.09 17.3 ± 0.12 8.3 ± 0.06 8.0 6.8 ± 0.07 6.4 ± 0.12 2.9 ± 0.05 17.9 ± 0.05 17.8 ± 0.13 9.9 ± 0.08 6.0 8.9 ± 0.13 8.0 ± 0.19 2.9 ± 0.09 21.0 ± 0.16 19.9 ± 0.08 13.2 ± 0.05 4.0 8.1 ± 0.07 7.8 ± 0.11 2.6 ± 0.05 20.1 ± 0.06 19.2 ± 0.08 12.6 ± 0.09 3.0 --- --- --- 19.3 ± 0.05 18.8 ± 0.07 12.1 ± 0.06 2.0 --- --- --- 18.9 ± 0.08 18.0 ± 0.05 11.0 ± 0.12 1.0 8.7 ± 0.23 6.7 ± 0.19 2.3 ± 0.16 18.2 ± 0.16 17.7 ± 0.18 8.5 ± 0.21 0.0 7 Days 3 Days One Day 7 Days 3 Days One Day Bending Strength (MPa) Compressive Strength (MPa) Polymer wt. %

16. 1- Compressive strength with aging time P(VC-co-VAc-co-VA)/plaster composites 2- Compressive strength with polymer concentration

17. Microstructure P(VC-co-VAc-co-VA)/plaster composites 1 wt. % 2 wt. % 3 wt. % 8 wt. % 4 wt. % 6 wt. %

18. Microstructure P(VC-co-VAc-co-VA)/plaster composites

19. X- Ray diffraction P(VC-co-VAc-co-VA)/plaster composites 1 wt. % 8 wt. % (a) (b)

20. Neat plaster PVA/plaster 1.0 wt. % P(VA- co -VAc- co -It)/plaster 1.2 wt. % P(VC- co -VAc- co -VA)/plaster 4.0 wt. % 28.5 MPa (56 %) 23.2 MPa (27 %) 21.0 MPa (15 %) 18.2 MPa

21. Bioactivity of Gypsum and Gypsum-Polymer Composites Ca and P concentrations

22. Bioactivity of Gypsum and Gypsum-Polymer Composites Variations in the pH of SBF solutions

23. Bioactivity of Gypsum and Gypsum-Polymer Composites Neat plaster Gypsum after treatment in SBF followed by 1.5 SBF for a week (Low Magnification) Gypsum after treatment in SBF followed by 1.5 SBF for a week ( High Magnification ) Energy-dispersive x-ray analysis of the spot marked by X in micrograph (c).

30. - Onderj Gedeon Doc.RNDr., Ph.D. - Ale š Helebrant Doc. Ing., CSc. - Jana Andertová Ing., CSc. - Jan Macháček Ing., Ph.D. - Dana Rohanová Dr. Ing. Acknowledgement

31. Thank you for your attention