Properties and degradation of castor oil-based fluoridated biopolyurethanes with different lengths of fluorinated segments.

To develop a durable, biodegradable polymer, this study successfully synthesized a castor-oil-based prepolymer by using methylene diphenyl diisocyanate as a hard segment, polycaprolactone as a soft segment, and castor oil as a functional monomer. We added perfluorinated alkyl segments with varying chain lengths into the castor-oil-based polymer to synthesize castor-oil-based fluoridated biopolyurethanes (FCOPUs) with different fluorinated segment lengths. The castor-oil-based polyurethanes with different fluorinated segment lengths had similar molecular weights, which enabled accurate analysis of the effect of the lengths of fluorinated segments on FCOPUs. Nuclear magnetic resonance (NMR) was used to perform 1H NMR, 19F NMR, 19F-19F COSY, 1H-19F COSY, and HMBC analyses on the FCOPU structures. The results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy curve fitting verified the interaction between C-F⋯H-N and C-F⋯C[double bond, length as m-dash]O. This interaction increased as the fluorinated segments became longer. Regarding the thermal properties of the FCOPUs, the thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis results revealed that long fluorinated segments were associated with increased thermal stability in the FCOPUs. The atomic force microscopy and tensile strength test suggested that long fluorinated segments contained in the FCOPUs increased the degree of phase separation and tensile strength in FCOPUs. Finally, we dipped the FCOPUs in a 3 wt% NaOH solution, calculated the weight loss of the FCOPUs, and observed their surface structure by using scanning electron microscopy.

Synthesis and Properties of Novel Polyurethanes Containing Long-Segment Fluorinated Chain Extenders.

In this study, novel biodegradable long-segment fluorine-containing polyurethane (PU) was synthesized using 4,4'-diphenylmethane diisocyanate (MDI) and 1H,1H,10H,10H-perfluor-1,10-decanediol (PFD) as hard segment, and polycaprolactone diol (PCL) as a biodegradable soft segment. Nuclear magnetic resonance (NMR) was used to perform ¹H NMR, 19F NMR, 19F⁻19F COSY, ¹H⁻19F COSY, and HMBC analyses on the PFD/PU structures. The results, together with those from Fourier transform infrared spectroscopy (FTIR), verified that the PFD/PUs had been successfully synthesized. Additionally, the soft segment and PFD were changed, after which FTIR and XPS peak-differentiation-imitating analyses were employed to examine the relationship of the hydrogen bonding reaction between the PFD chain extender and PU. Subsequently, atomic force microscopy was used to investigate the changes in the microphase structure between the PFD chain extender and PU, after which the effects of the thermal properties between them were investigated through thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. Finally, the effects of the PFD chain extender on the mechanical properties of the PU were investigated through a tensile strength test.

Tetra-kis[µ-1,3-bis-(4,5-dihydro-1,3-oxazol-2-yl)benzene-κ(2)N:N']tris-ilver(I) tris-(hexa-fluoridophosphate).

In the title compound, [Ag(3)(C(12)H(12)N(2)O(2))(4)](PF(6))(3), one Ag(I) ion, lying on a twofold rotation axis, is coordinated by four N atoms from four 1,3-bis-(4,5-dihydro-1,3-oxazol-2-yl)benzene (L) ligands in a distorted tetra-hedral geometry and the other Ag(I) ion is coordinated by two N atoms from two L ligands in a bent arrangement [N-Ag-N = 169.03 (17)°]. Two L ligands adopt a syn conformation, while the other two adopt an anti conformation. They bridge adjacent Ag(I) ions, forming a trinuclear complex. One of the PF(6) (-) anions is half-occupied, with the P atom located on a twofold rotation axis. The PF(6) (-) anions link the complex mol-ecules via Ag⋯F inter-actions [2.80 (2) and 2.85 (2) Å] into a polymeric chain along [100].

Poly[[µ(2)-1,4-bis-(4,5-dihydro-1,3-oxazol-2-yl)benzene-κN:N']di-µ(2)-chlorido-cadmium].

In the title coordination polymer, [CdCl(2)(C(12)H(12)N(2)O(2))](n), the Cd(II) ion, situated on an inversion center, is coordinated by four bridging Cl atoms and two N atoms from two 1,4-bis-(4,5-dihydro-1,3--oxazol-2-yl)benzene (L) ligands in a distorted octa-hedral geometry. Each L ligand also lies across an inversion center and bridges two Cd(II) ions, forming infinite two-dimensional recta-ngular layers running parallel to (010).