Synthesis and radiation degradation of vinyl polymers with fluorine: search for improved lithographic resists. [Gamma rays]

Journal Article · Mon Dec 01 00:00:00 EST 1980 · J. Polym. Sci., Polym. Chem. Ed.; (United States)

DOI:https://doi.org/10.1002/pol.1980.170181208· OSTI ID:6674649

Pittman, Jr, C U ^[1]; Chen, C Y; Ueda, M; Helbert, J N; Kwiatkowski, J H

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1. Univ. of Alabama, University

Homopolymers of methyl ..cap alpha..-fluoroacrylate (MFA), trifluoroethyl methacrylate (TFEM), and hexafluoroisopropyl methacrylate (HFIM) were prepared, as were their methyl methacrylate (MMA) copolymers. Copolymers of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) with MMA were also prepared. The radiation susceptibilities of these polymers were measured by the /sup 60/Co ..gamma..-irradiation method, in which molecular weights were measured by membrane osmometry and gel permeation chromatography (GPC). All the copolymers degraded by predominant chain scission except poly(methyl ..cap alpha..-fluoroacrylate), (PMFA), which crosslinks even at low doses (ca. 1 Mrad). The G/sub s/-G/sub x/ and G/sub s/ values of the chain scissioning polymers and copolymers are higher than those of poly(methyl methacrylate) PMMA reference. The high susceptibility of PMFA homopolymer to crosslinking is in contrast to that of poly(methyl ..cap alpha..-chloroacrylate), as we reported earlier. This effect is interpreted as resulting from extensive hydrogen fluoride and polyenyl radical formation, which leads to facile crosslinking. However, incorporation of the MFA monomer unit causes the (22/78) MFA/MMA copolymer to degrade with a larger value of G/sub s/ that PMMA. Apparently a second-order process leads to crosslinking in PMFA and this is retarded in the copolymer. In the homopolymers of HFIM and TFEM and in the HFIM-MMA and TFEM-MMA copolymers the HFIM and TFEM components facilitate degradation with negligible crosslinking. The increased degradation susceptibility of VDF and CTFE copolymers with MMA over that of PMMA is attributed to processes at the VDF or CTFE components (present in smaller concentrations (3 to 5 mole %) than the threshold levels (25 to 50% necessary for significant crosslinking).

• OSTI ID: 6674649
• Journal Information: J. Polym. Sci., Polym. Chem. Ed.; (United States), Vol. 18:12
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
ACRYLIC ACID ESTERS
CHEMICAL RADIATION EFFECTS
CHLORINATED ALIPHATIC HYDROCARBONS
FLUORINATED ALIPHATIC HYDROCARBONS
METHACRYLIC ACID ESTERS
METHYL METHACRYLATE
VINYL MONOMERS
ALKENES
CHEMICAL PREPARATION
COPOLYMERIZATION
CROSS-LINKING
G VALUE
GAMMA RADIATION
HYDROFLUORIC ACID
MOLECULAR WEIGHT
NMR SPECTRA
POLYMERIZATION
RADICALS
VISCOSITY
X-RAY DIFFRACTION
CARBOXYLIC ACID ESTERS
CHEMICAL REACTIONS
CHEMISTRY
COHERENT SCATTERING
DIFFRACTION
ELECTROMAGNETIC RADIATION
ESTERS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IONIZING RADIATIONS
MONOMERS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
SCATTERING
SPECTRA
SYNTHESIS
400600* - Radiation Chemistry