1. 1 Water Soluble Polymers for Paper Strength Li Zhu Department of Chemical Engineering McMaster University, Hamilton, Ontario, Canada

2. 2 Outline u Introduction u Dry strength resins u Wet strength resins

3. 3 Cellulose Structure REF. Pulp and Paper. Chemistry and chemical Technology Vol. I

4. 4 Hydrogen Bonds

5. 5 Dry Strength Resin--- Starch u Glucose units

6. 6 Cationic Starch

7. 7 Cationic PAM

8. 8 Conclusion---I u Dry strength resin should contain: D Cationic charges D H-bonding potential.

9. 9 Homo-crosslinking

10. 10 Wet--- Urea Formaldehyde Resin

11. 11 Melanine Formaldehyde Resin

12. 12 Co-crosslinking

13. 13 Wet Strength Enhancing Ref. Charles E. Farley, wet-strength resin and application, Chapter 3

14. 14 Cationic Aldehyde Starch

15. 15 Conclusion---II u Wet strength resin should be able to: D Homo-crosslinking D Covalent bonding with fibers

16. 16 Http://www.papersci.mcmaster.ca