Vibrational spectroscopic study and structure calculation for model compounds and polyurethanes

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5719398

Wang, Q

Vibrational spectroscopy has been applied to the study of a small ring molecule, three model urethane compounds and Poly[4,4[prime]-bis(6-hydroxyhexyloxy)biphenyl-co-2,4-toluenediisocyanate] (2,4-TDI polyurethane) systems. The computer program POLYGRAF was used to estimate the stability of some conformers of the three model compounds. Grazing angle microscopy was used to study the surface structure of thin films of polyurethane. The synthesis, far infrared spectra, temperature dependent mid-infrared spectra and the Fourier transform Raman spectra are reported for polycrystalline samples of three model urethanes, 1,3-phenyl di(methyl carbamate) (1,3-PDI based urethane), 2,6-toluene di(methyl carbamate) (2,6-TDI based urethane), and 2,4-toluene di(methyl carbamate) (2,4-TDI based urethane). Geometry optimization is reported for phenyl methyl carbamate by ab initio and molecular mechanics methods, and of the three model urethanes by molecular mechanics methods using the Dreiding I force field. The results suggest that in isotropic surroundings only a very small number of the many possible conformers of the urethane groups in these molecules contribute appreciably to the structure. The intermolecular interaction, morphology and microstructure of 2,4-TDI polyurethane are studied. A molecular interpretation of hydrogen bonding behavior is given. The temperature dependence of infrared spectra of the 2,4-TDI polyurethane films are reported together with some kinetic data. A very thin film was prepared to study the surface behavior of 2,4-TDI polyurethane. An infrared spectrum was obtained by grazing angle reflection-absorption. The results suggest that 2,4-TDI polyurethane has a layered structure and that most of the NH groups and carbonyl groups are free on the surface. The infrared spectra of 1,4-cyclohexadiene and 1,4-cyclohexadiene-3,3,6,6-d4 were recorded in the gas phase at room temperature.

• Research Organization: Massachusetts Univ., Amherst, MA (United States)
• OSTI ID: 5719398
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
74 ATOMIC AND MOLECULAR PHYSICS
POLYURETHANES
STRUCTURAL CHEMICAL ANALYSIS
VIBRATIONAL STATES
BIPHENYL
INFRARED SPECTRA
INTERMOLECULAR FORCES
MICROSTRUCTURE
MORPHOLOGY
P CODES
RAMAN SPECTRA
TEMPERATURE DEPENDENCE
THIN FILMS
TOLUENE
ALKYLATED AROMATICS
AROMATICS
COMPUTER CODES
ENERGY LEVELS
EXCITED STATES
FILMS
HYDROCARBONS
MATERIALS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYAMIDES
POLYMERS
SPECTRA
SYNTHETIC MATERIALS
400201* - Chemical & Physicochemical Properties
360602 - Other Materials- Structure & Phase Studies
664000 - Atomic & Molecular Physics- (1992-)