Poly photo-cross-linking

Keywords Hydrogel Photo cross-linking Poly(A-isopropy 1-acrylamide) Surface plasmon resonance spectroscopy... 

Photo-Cross-Linking and Imidization of Poly(amic add) Methacrylate Esters... 

Reiser and E. Ktts, Cbaracteristic curve of crossUnking photoresists, Photogr. Sci. Eng. 20, 225 (1976) J. Pinter, Z. Haniotis, K. Meier, and H. Zweifel, A numerical method for calculation of gel point exposure energies from experimental gel curves Photo cross linking of unsensitized poly[vinyl 3 (3,4 dihydro 1,2 naphthalene dicarboxylic acid imidyl) proprionate], J. Imaging Sci. 30, 259 (1986). 

PET reactions of benzylic silanes with polycyano-aromatic compounds have been applied to photoresist and electron-beam resist technologies. "" The photoreaction of poly(4-trimethylsilyl-methylstyrene) in benzene-acetonitrile with DCB affords insoluble polymer via photo-cross-linking, which contains 4-cyanophenyl-methyl groups. In the case of 1,2,4,5-tetracyanobenzene, soluble 2,4,5-tricyanophenylmethyl-substituted polystyrene is produced. But,... 

Elisseeff, J. et al.. Synthesis and characterization of photo-cross-linked polymers based on poly(D-lactic acidaspartic acid). Macromolecules, 30, 2182,1997. 

Scheme 7.7 shows, as a typical example, the photo-cross-linking of a co-poly-peptide [30]. 

Alternatively, bisazides, i.e. low molar mass compounds containing two azide groups, can be added to the polymer. Several commercially used bisazides are presented in Table 7.2. Many linear polymers can be photo-cross-linked with the aid of bisazides [17]. Of note in this context is poly(cis-isoprene), which contains some cyclized structures (Chart 7.7). It has been frequently applied as a resist material in photolithography applications. 

A water-soluble bisazide (see Chart 7.8) is applicable for the photo-cross-linking of water-processable polymeric systems containing polyacrylamide or poly(vi-nyl pyrrolidone). 

Typical of this type of photo-cross-linking is the case of poly(4-hydroxystyrene) (see Chart 7.10) [34]. 

The earhest photoresists used in integrated circuit manufacture consisted of polymers that were rendered insoluble by photo-cross-linking and thus operated in the negative tone mode. For instance, partially cycUzed poly(cis-isoprene) containing a bisazide as additive served for a long time as the workhorse resist material in photohthography applications [15]. This system has already been described in Section 7.2.3. Subsequently, Novolak-based positively functioning sys-... 

Polyol monomer like xylitol was also used to compose biodegradable polymer poly(xylitol citrate) (PXC) with citric acid by a simple thermal polycondensation. The abundant pendent hydroxyl groups on PXC, mostly introduced by xylitol, were used to react with methacrylic anhydride to obtain double bond functional PXC (PXCma), which can be formed into a bioelastomer network by photo-cross-linking [96]. 

Chapanian, R., Tse, M.Y., Pang, S.C., and Amsden, B.G. (2010) Long term in vivo degradation and tissue response to photo-cross-linked elastomers prepared from star-shaped prepolymers of poly(epsilon-caprolactone-co-D,L-lactide). /. Biomed. Mater. Res. Part A, 92A (3), 830-842. 

Wang, S., Kempen, D.H., Simha, N.X., Lewis, J.L., Windebank, A.J., Yaszemski, M.J. et al. (2008) Photo-cross-linked hybrid polymer networks consisting of poly(propylene fumarate) and poly(caprolactone fumarate) controlled physical properties and regulated bone and nerve cell responses. Biomacromolecules, 9 (4), 1229—1241. 

Chen, X.-S., and Wang, J. (2007) Synthesis and characterization of photo-cross-linked hydrogels based on biodegradable polyphosphoesters and poly(ethylene glycol) copolymers. Biomacromolecules, 8 (11), 3375—3381. 

Beuerman, R.W. (2007) Synthesis, characterization, and in vitro degradation of a biodegradable photo-cross-linked film from liquid poly(epsilon-caprolactone-co-lactide-co-glycolide) diacrylate. Biomacromolecules, 8 (2), 376-385. 

LB coatings have been used as photoresists. In the area of ultrathin (single molecule) photoresists, spin-coated polymers tend to lack the consistency in structure and thickness necessary for these applications. However, preformed polymer LB films or polymerized monomeric LB films are extremely uniform, and can be used in these apphcations. Photo-cross-linking of poly(p-phenylene) and photopolymerization of ft>-tricosenoic acid and methacrylic acid LB films have been investigated (20,21). Etching resulted in patterns that had resolutions of ca 60 nm. (see Lithographic Resists)... 

Fig. 6. The photo-cross-linking of poly[( 4-ethylphenoxy)(phenoxy)phosphazene] with benzophenone photoinitiator.

Pitarresi G, Pierro P, Palumbo FS, Tripodo G, Giommana G. Photo-cross-linked hydrogels with polysaccharide-poly (amino acid) structure new biomaterials for pharmaceutical applications. Biomacromolecules. 2006 7 1302-10. 

J.R Fisher, T.A. Holland, D. Dean, PS. Engel, and A.G. Mikos, Synthesis and properties of photo cross-linked poly(propylene fumarate) scaffolds,/. Biomater. Sci. Polym. Ed., 12 (6),... 

Figure 6 Photo-cross-link kinetics observed for an anthracene-labeled poly(ethyl acrylate) (PEA-A) under various light intensities observed at 25 °C [45].

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