Benzoylated polystyrene (BPS) was subjected to UV radiation in solution in the presence of isopropanol where upon, it was observed to undergo essentially quantitative crosslinking to form polystyrene resin with tertiary hydroxyl functionality. The crosslinking kinetics was followed by IR spectroscopy. The desired degree of crosslinking was accomplished by controlling the extent of benzoylation of the polymer. Following crosslinking, the gels were freeze-dried and suitably characterized by solid state NMR and IR spectroscopic techniques. Scanning electron microscopic studies reveal the formation of porous network. Some of the crosslinked resins, dried suitably, exhibit high surface area as confirmed by BET adsorption isotherm studies.

R. Dhamodharan

Department Of Chemistry

Beena George

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Photochemical synthesis and characterization of hypercrosslinked polystyrene, a novel porous organic material†

Journal of Macromolecular Science - Pure and Applied Chemistry

Several synthetic approaches are available to make photoresist polymers for deep UV (DUV) lithography. Two approaches were widely used in semiconductor manufacturing: i) direct polymerization of corresponding monomers by (controlled) radical, (living) ionic polymerization ii) thermal or chemical catalyzed deprotection or protection of the macromolecules. The latter approach which is also called polymer modification chemistry (PMC) or polymer analogous chemistry offers several advantageous over the direct polymerization approach. In this presentation, we will provide an overview on the preparation and basic lithographically important characterization of new polymers based on poly(4-(1-hydroxyalkyl)styrene-co-styrene) [Poly(4-HAS-co-S)]. These polymers were synthesized for the first time by PMC and this methodology is an simple alternative for the synthesis of poly(4-HAS-co-S) than conventionally used synthetically challenging free radical or low temperature anionic polymerization of the protected monomer. We have synthesized high and low molecular weight (Mn) polymers with mole fraction of functional group ranging from partial to complete functionalization. Several formulations based on poly(4-HAS-co-S) were developed and tested for negative tone imaging at DUV lithography. Lithographic performance of these polymers at DUV lithography will be compared with their molecular weight and mole fraction of functional groups.

Proceedings of SPIE - The International Society for Optical Engineering

Poly4-(1-hydroxyalkyl)styrene based photoresist materials: Design, synthesis and their lithographic performance

The amine functionality is introduced onto a glass surface by using 3-(aminopropyl)-triethoxysilane (3-APTS)-a silane coupling agent-as well as by the adsorption of poly(L-lysine). The amine functionality is introduced onto the hydroxyl-functionalized polychlorotrifluoroethylene surface (PCTFE-OH) using 3-APTS as well. The amine-functionalized surfaces were thoroughly characterized by X-ray photoelectron spectroscopy (XPS). Selected polysaccharides, involved in fouling processes, such as alginic acid and chondroitin sulfate-A were allowed to adsorb onto amine-functionalized surfaces. It is shown that alginic acid adsorbs from calcium-free artificial seawater onto amine-functionalized glass surface prepared by the adsorption of poly(L-lysine) and onto amine-functionalized polychlorotrifluoroethylene surfaces (PCTFE-NH2). The adsorption of alginic acid to PCTFE-NH2 is very rapid, resulting in high-affinity isotherms and approx. 5 angstrom thick dry overlayer of the polysaccharide. In addition, we observe that the adsorbed alginic acid protects the PCTFE-NH2 surface from hydrolysis by phosphate buffer 2 and from hydrolysis/oxidation by copper(II) acetate monohydrate solution. It is also shown that chondroitin sulfate-A adsorbs from potassium hydrogen phthalate buffer to the amine-functionalized glass surface prepared by the reaction between silanol groups on glass and 3-APTS. It is observed that alginic acid and chondroitin sulfate-A do not adsorb to the unmodified glass surface, which is polar and negatively charged, and the PCTFE surface, which is nonpolar, from aqueous solutions under various solution conditions. This study clearly indicates the importance of surface functional groups on the adsorption of polysaccharides, an important preliminary step in the biofouling of surfaces.

Macromolecules

Adsorption of alginic acid and chondroitin sulfate-A to amine functionality introduced on polychlorotrifluoroethylene and glass surfaces

Polymer

The rigid amorphous fraction of isotactic polystyrene prepared by freeze-drying from dilute solutions

Structure of freeze-dried atactic polystyrene from dilute solutions

MRS Proceedings

Tailoring the Pore Size of Hypercrosslinked Polymer Foams

Reactive Polymers

Sorption of organic compounds from aqueous media by hypercrosslinked polystyrene sorbents ‘Styrosorbrs

Photochemical synthesis and characterization of hypercrosslinked polystyrene, a novel porous organic material

Journal	Journal of Macromolecular Science - Pure and Applied Chemistry
Publisher	Marcel Dekker Inc.
ISSN	10601325
Open Access	No