Rheology and porosity control of poly(2-hydroxyethyl methacrylate) hydrogels

Abstract Swelling and dynamic mechanical behavior in a broad frequency range of homogeneous and porous poly(2-hydroxyethyl methacrylate) gels were studied in relation to their matrix structure, gel morphology and nature of the swelling medium. Very lightly cross-linked gels showed up relatively large mechanical losses caused by slow relaxation of hydrophobic physical associates still proceeding at frequency 10−3 Hz. The macroporous gels of fused-spheres type morphology contained many dangling aggregates not bearing the stress which caused concentration of the stresses in the load bearing paths through the matrix. This is the reason for the sudden drop of storage modulus. In the α-relaxation region, the loss factors for homogeneous and porous gels merged into a single master curve. Reswelling of gels in a poor solvent caused a decrease of the swelling degree and shifted their α-relaxation to lower frequencies; reswelling in good solvent shifted the maximum of α-relaxation to higher frequencies.

[1]  F. Švec.  Porous polymer monoliths: amazingly wide variety of techniques enabling their preparation. , 2010, Journal of chromatography. A.

[2]  W. Pechhold,et al.  Piezoelectric Rotary Vibrator (PRV) – a new oscillating rheometer for linear viscoelasticity , 2002 .

[3]  K. Dušek,et al.  Effect of diluents on the microsyneresis in poly(2-hydroxyethyl methacrylate) gels induced by temperature changes , 1971 .

[4]  G. Kavanagh,et al.  Rheological characterisation of polymer gels , 1998 .

[5]  A. Mikos,et al.  Preparation of macroporous poly(2-hydroxyethyl methacrylate) hydrogels by enhanced phase separation. , 2000, Biomaterials.

[6]  D. Hukins,et al.  Rheological properties of poly(2-hydroxyethyl methacrylate) (pHEMA) as a function of water content and deformation frequency , 2003, Journal of materials science. Materials in medicine.

[7]  Miroslava Dušková-Smrčková,et al.  Network structure formation during crosslinking of organic coating systems , 2000 .

[8]  K. Matyjaszewski,et al.  Design and preparation of porous polymers. , 2012, Chemical reviews.

[9]  S. Kasapis,et al.  The use of Arrhenius and WLF kinetics to rationalise the mechanical spectrum in high sugar gellan systems , 1998 .

[10]  R. Landel,et al.  The Temperature Dependence of Relaxation Mechanisms in Amorphous Polymers and Other Glass-Forming Liquids , 1955 .

[11]  K. Dušek,et al.  Solubilization of poly(2-hydroxyethyl methacrylate) with aqueous salt solutions; Swelling of gels , 1977 .

[12]  Charles Tanford,et al.  The hydrophobic effect , 1980 .

[13]  D. J. Montgomery,et al.  The physics of rubber elasticity , 1949 .

[14]  Daniel Chappard,et al.  2-Hydroxyethyl Methacrylate (HEMA): Chemical Properties and Applications in Biomedical Fields , 1992 .

[15]  Torsten Remmler,et al.  Rheological properties of homogeneous and heterogeneous poly(2-hydroxyethyl methacrylate) hydrogels , 2012 .

[16]  M. Antonietti,et al.  Porous polymers and resins for biotechnological and biomedical applications. , 2002, Journal of biotechnology.

[17]  K. Dušek,et al.  Phase separation in poly(2-hydroxyethyl methacrylate) gels in the presence of water , 1971 .

[18]  I J Constable,et al.  Poly(2-hydroxyethyl methacrylate) sponges as implant materials: in vivo and in vitro evaluation of cellular invasion. , 1993, Biomaterials.

[19]  R. Prud’homme,et al.  Rheology of Guar and HPG Cross-Linked by Borate , 1992 .

[20]  S. Kasapis,et al.  The glass transition zone in high solids pectin and gellan preparations , 1997 .

[21]  C. A. Dreiss,et al.  Enzymatically cross-linked tilapia gelatin hydrogels: physical, chemical, and hybrid networks. , 2011, Biomacromolecules.

[22]  J. Kopeček,et al.  Effect of the structure of poly(glycol monomethacrylate) gel on the calcification of implants , 2005, Calcified Tissue Research.