Skip to main content

Synthesis and swelling behavior of pH- and temperature-sensitive poly[2-(dimethylamino)ethyl methacrylate-co-2-acrylamido-2-methylpropane-1-sulfonic acid] hydrogels


Poly[2-(dimethylamino)ethyl methacrylate-co-2-acrylamido-2-methylpropane-1-sulfonic acid], poly(DMAEMA-co-AMPS), hydrogels were prepared by chain polymerization in water at 60 °C in the presence of tetraethyleneglycol diacrylate (TEGDA) as crosslinking agent. Ammonium persulfate (APS) and N,N,N’,N’-tetramethylethylenediamine (TEMED) were used as initiator and accelerator, respectively. Hydrogels with different feed compositions were prepared by keeping the total monomer concentration constant at 1 or 0.5 M. The concentration of TEGDA in the feed was adjusted so that it made for 3 or 2 mol % of the total monomer content while it was 1% for APS. In order to observe the effects of pH and ionic strength of the medium on swelling, the equilibrium swelling behavior of these hydrogels were investigated both in distilled water at various temperatures between 30 and 90 °C and in different buffer solutions with pH of 2.8, 5.3, 7.0, 10.0, and 12.4 at constant ionic strength (I=0.08 mol/l) at room temperature. The effects of temperature and co-monomer AMPS content on the swelling behavior of poly(DMAEMA-co-AMPS) in distilled water were also investigated.

The copolymers with equimolar contents of DMAEMA and AMPS displayed minimum swelling both in distilled water and in buffer solutions due to ionic complex formation. Their swelling values in distilled water between 30 and 90 °C were constant. While equilibrium swelling values of copolymers in buffer solutions with pH between 2.8 and 7 were almost constant, they increased with increasing pH. The increase in the AMPS content and decrease in initial monomer concentration increased the equilibrium swelling values of copolymers.

This is a preview of subscription content, access via your institution.


  1. Ni C, Zhu XX (2004) Eur Polym J 40:1075

    Google Scholar 

  2. Qiu Y, Park K (2001) Adv Drug Delivery Rev 53:321

    Google Scholar 

  3. Yanfeng C, Min Y (2001) Radiat Phys and Chem 61:65

    Google Scholar 

  4. Maolin Z, Yanfeng C, Min Y, Hongfei H (2004) Polym Int 53:33

  5. Kim EJ, Cho SH, Yuk SH (2001) Biomaterials 22:2495

    Google Scholar 

  6. Travas-Sejdic J, Easteal AJ (2000) Polymer 41:7451

    Google Scholar 

  7. Han MH, Kim JW, Kim J, Ko JY, Magda JJ, Han IS (2003) Polymer 44:4541

  8. Yıldız B, Işık B, Kış M, Birgül Ö (2003) J Appl Polym Sci 88:2028

    Google Scholar 

  9. Heijl JMD, Du Perez FE (2004) Polymer 45:6771

    Google Scholar 

  10. Yıldız B, Işık B, Kış M (2001) Polymer 42:2521

    Google Scholar 

  11. Yı YD, Bae YC (1998) J App Polym Sci 67:2087

    Google Scholar 

  12. Kakinoki S, Kaetsu I, Nakayama M, Sutani K, Uchida K, Yukutake K (2003) Radiat Phys and Chem 67:685

    Google Scholar 

  13. Sutani K, Kaetsu I, Uchida K, Matsubara Y (2002) Radiat Phys and Chem 64:331

    Google Scholar 

  14. Perrin DD, Dempsey B. Buffers for pH and Metal Ion Control. Canberra: Academic, 1973

  15. Zhai M, Chen Y, Yi M, Ha H (2004) Polym Int 53:33

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Gülten Gürdağ.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Çavuş, S., Gürdağ, G. Synthesis and swelling behavior of pH- and temperature-sensitive poly[2-(dimethylamino)ethyl methacrylate-co-2-acrylamido-2-methylpropane-1-sulfonic acid] hydrogels. Polym. Bull. 58, 235–242 (2007).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Lower Critical Solution Temperature
  • Monomer Concentration
  • Feed Composition
  • Constant Ionic Strength