1D nano- and microbelts self-assembled from the organic-inorganic hybrid molecules: oxadiazole-containing cyclotriphosphazene.

A new oxadiazole-containing cyclotriphosphazene, namely, hexakis-(4-(5-phenyl-1,3,4-oxazodiazol-2-yl)-phenoxy)-cyclotriphosphazene (HPCP) was synthesized. Single-crystal nano- and microbelts of HPCP were self-assembly via two simple solution methods. The shapes of the as-prepared nano- and microstructures can be readily controlled by varying the solvent and aging time in the self-assembly process. A growth mechanism was proposed for the formation of the 1D morphological structures. Crystal structure analysis demonstrated that the overlap between the aryl units attached to the cyclotriphosphazene backbone forms effective intermolecular π-π linking for crystal growth. Electronic and optical properties of the as-prepared nano- and microstructures are investigated.

Phosphorus-containing polymers from THPS. IV: Synthesis and properties of phosphorus-containing polybenzoxazines as a green route for recycling toxic phosphine (PH3) tail gas.

A convenient route to convert the highly toxic phosphine (PH3) tail gas into high-performance polybenzoxazines was first described in this paper. Two aliphatic polyamines, namely tris(aminomethyl)phosphine oxide and bis(aminomethyl)phenylphosphine oxide, were synthesized from tetrakis(hydroxymethyl)phosphonium sulfate (THPS), a green derivative of PH3 tail gas. And then two novel phosphorus-containing benzoxazine monomers, tris(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl)phosphine oxide (TBOz) and benzylbis(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl) phosphine oxide (BBOz) were prepared by three-steps procedure. FT-IR and DSC technologies were adopted to study the thermal-initiated polymerization behaviors of two benzoxazine monomers. Thermal properties of these crosslinked polymers were studied by TGA and DMA. The results display that the polybenzoxazines (PTBOz and PBBOz) exhibite good thermal stabilities and high glass transition temperatures. The char yield of polybanzoxazine is high as 47% and indiactes that phosphorus-containing polybenzoxazines show high fire-retardancy. The surface free energies of the PTBOz and PBBOz are 37.1 and 40.4mJm-2 by Owens two-liquid method. The dielectric properties of the PTBOz and PBBOz remaine near constant in the experimental frequency range.

Crosslinking property of an oligomeric unsaturated phosphoester used as a potential injectable biomaterial.

An unsaturated polyphosphoester (UPPE) that has double bonds in repeatable units could crosslink with a vinyl monomer. A study of how the crosslinking temperature, setting time and mechanical properties are affected by the UPPE molecular weight, N-vinyl pyrrolidinone (NVP)/UPPE ratio and benzoyl peroxide (BPO)/UPPE ratio was conducted. The results of the study indicated that the maximum crosslinking temperature is between 41.1 degrees C and 82.3 degrees C, which is lower than the 97 degrees C of poly(methyl methacrylate) bone cement. The BPO concentration strongly affected the maximum temperature and setting time. High concentration of BPO gives a rapid polymerization rate, causing reaction heat to be released immediately. The compressive strength and compressive modulus will be enhanced with an increase in the NVP/UPPE ratio, the UPPE molecular weight and the BPO concentration. For all formulations, the compressive strength values are between 3.3 MPa and 11.0 MPa and the compressive modulus values are between 4.9 MPa and 101.9 MPa. These initial studies suggest that UPPE is one kind of potential injectable bone tissue engineering scaffold material.