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

Journal Article · Sun Nov 30 23:00:00 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), Journal Name: J. Polym. Sci., Polym. Chem. Ed.; (United States) Vol. 18:12; ISSN JPLCA
• Country of Publication: United States
• Language: English

Related Subjects

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