On the presence of polytetrahydrofuran in the polyspiro-phosphazenes [NP(O2C12H8)]n prepared from [NPCl2]n and 2,2?-dihydroxybiphenyl in THF as solvent

Abstract

Polydichlorophosphazene [NPCl 2 ] n reacts with the diphenol 2,2Ј-(HO)C 6 H 4 -C 6 H 4 (OH) in THF in the presence of K 2 CO 3 to give the polymers [NP(O 2 C 12 H 8 ) ⅐ x(OC 4 H 8 )] n (1) that contain variable ammouts of polytetrahydrofuran (PTHF) with x ranging from 0.05 to 0.8. This PTHF content (x) depends on the method followed to prepare the THF solutions of [NPCl 2 ] n used for the reactions with the biphenol and can be made negligibly small, forming these solutions in the presence of K 2 CO 3 . This reveals the presence in the [NPCl 2 ] n of acidic species capable of catalyzing the ring opening polymerization of THF. Polyphosphazene [NP(O 2 C 12 H 8 )] n (2) was prepared completely free of PTHF using dioxane as solvent. A comparison of the thermal behavior and morphological data of the polymers 1, 2, PTHF (5), and mixtures of [NP(O 2 C 12 H 8 )] n ϩ x(OC 4 H 8 ) m (4) revealed that the products 1 are strongly interacting polymer blends and ruled out the possibility of block copolymers.

Molecular Dynamics (MD) Simulations and Large‐Angle X‐ray Scattering (LAXS) Studies of the Solid‐State Structure and Assembly of Isotactic (R)‐Poly(2,2′‐dioxy‐1,1′‐binaphthyl‐)phosphazene in the Bulk State and in the Cast Film

“…Samples : The polymer ( R )‐[NP(O 2 C 20 H 12 )] n , a very pale yellow powder, was prepared by the previously described method,6 but with some modifications. The reaction was carried out in tetrahydrofuran (THF) instead of 1,4‐dioxane, the starting [NPCl 2 ] n was obtained by the method of Magill,19 but its solution in THF was made in the presence of solid K 2 CO 3 , to avoid the formation of poly‐THF,20, 21 and, in order to prevent the presence of solvents in the final polymer (these are very easily retained and difficult to remove6), the purification was carried out by three consecutive precipitations from THF/water (instead of THF/isopropanol and THF/hexanes) and the product was dried over phosphorous pentoxide in a desiccator at low pressure. Elemental analysis calcd (%) for final product:C 73.0, H 3.67, N 4.25; found: C 71.3, H 3.74, N 4.41.…”

Experimental and Theoretical Study of the Hydrolytical Stability of Isolable Poly(2,2‘-dioxy-1,1‘-biphenoxyphosphazene)s with [NPCl2] Units

“…Although the interplanar distances could not be measured accurately, they were clearly between 10 and 11 Å, i.e., lower than that of the homopolymer [NP(O 2 C 12 H 8 )] n (12.1 Å). 11 It is known that the presence of composition defects in the phosphazene chains originated by incomplete macromolecular substitution of chlorines may prevent the appearance of mesophases, 12 but the limiting residual chlorine might depend on the type of phosphazene units present in the polymer, which explains the thermotropic behavior of 1a and 1b (x ) 0.12 and 0.28) and the absence of mesophases in 1c (x ) 0.43).…”

“…Thus, the thermogram of a polymer [NP(O 2 C 12 H 8 )] n having only 1.3% chorine (i.e., 1 with x ) 0.05) showed only a sharp weight loss (-49%) between 320 and 660°C (centered at 507°C), approaching that of the chlorine-free biphenoxyphosphazene homopolymer with only ppm of residual Cl. 11 In the case of 1a (x ) 0.12), however, the thermogram showed a first decomposition (5%) from 210 to 430°C, which was partially overlapped with the main loss (-35%) centered at 525°C. In the cases of 1b and 1c, various overlapped decomposition processes were evident, resulting in an almost continuous loss (-52% for 1b and -32% for 1c) from ca.…”

Rheological Features of a Novel Poly(spiro phosphazene)

“…The synthesis of 1 (almost free of polytetrahydrofuran) was carried out by scaling the procedure originally published [4] as described below. The starting poly(dichlorophosphazene) Full Paper: A study of the rheology of a new poly (2,29-dioxybiphenyl)phosphazene is presented.…”

“…[1] They are usually prepared by the chlorine substitution reactions of the parent poly(dichlorophosphazene) [NPCl 2 ] n , that can be obtained in many different routes. [1,2] Previously [3,4] we have reported the preparation of the poly(2,29-dioxybiphenyl)phosphazene [NP(O 2 C 12 H 8 )] n (1), that has a refraction index of 1.64 and may be used in optical waveguiding. [5] The molecular structure of Figure 1 is supported by 1 H NMR spectra.…”