Synthesis and Characterization of Aminoorganosiloxane-Bearing Polyphosphazenes:  New Properties by the Elimination of Hydrogen Bonding

Abstract

The synthesis of new hybrid polyphosphazene−siloxane polymers is described. These polymers contain a polyphosphazene backbone and [(N-methylamino)propyl]siloxane side groups, −N(Me)(CH2)3SiMe2OSiMe3 or −N(Me)(CH2)3SiMe2OSiMe2OSiMe3, in ratios of 1:1 and 1:3 with trifluoroethoxy, 2-(2-methoxyethoxy)ethoxy, or p-methylphenoxy cosubstituents. The synthetic method utilized allows the polymer properties to be tuned by variations in the cosubstituent ratios. The polymers were characterized by 31P, 13C, and 1H NMR, differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and elemental analysis. The percent loading of siloxane-containing side groups and the nature of the cosubstituents were correlated to the glass transition temperatures. The glass transition temperatures ranged from −83 to −22 °C. The longer, trisiloxane-containing units generated lower glass transition temperatures than did the analogous polymers with disiloxane-containing side groups. Several polymers were further characterized by dynamic mechanical analysis (DMA). In addition to glass transition temperatures, other transitions attributed to the siloxane side groups were detected at approximately −124 °C.

Synthesis and Characterization of Trifluoroethoxy Polyphosphazenes Containing Polyhedral Oligomeric Silsesquioxane (POSS) Side Groups

“…For example, an elemental analysis of polymer 5 shows that 1.12% unreacted chlorine remained. However, the remaining chlorine atoms in polymers 2 – 11 were not sensitive to water and could represent hydrogen chloride molecules coordinated to the polymers. , Furthermore, as discussed below, the sensitivity of this system to high dilutions in acidic media and to depolymerization during the synthesis process is an aspect that needs to be taken into account.…”

“…In terms of different side groups and architectures, poly­(organo­phosphazenes) are the largest class of inorganic–organic macromolecules, followed by silicon-containing polymers. Intriguing possibilities exist for combining polyphosphazene structures with organosilicon side groups. , In this paper we examine the property changes that result from the linkage of polyhedral oligomeric silsesquioxane (POSS) side units to a polyphosphazene chain, making use of the macromolecular substitution approach in which both fluoro-organic and organosilicon side groups are linked to the polymer skeleton via chlorine replacement reactions: …”

“…In this study we have examined the use of POSS and trifluoroethoxy cosubstituents to determine the influence of the organosilicon moieties on the properties of a well-characterized poly­(fluoro­alkoxy­phosphazene). The unusual shape, stability, and dimensions of POSS side groups provide an opportunity to obtain more information about the properties of hybrid phosphazene–organosiloxane polymers, a class that has received only minimal attention up to this point. , In a recent related study, Park et al reported a system in which two POSS cages were assembled by corner-capping around organic substituents linked to a polyphosphazene chain. These polymers are different in concept and properties from the new species to be discussed here and require a more complex and challenging synthesis sequence.…”

Synthesis and Characterization of Organometallic Polyphosphazenes and Their Applications in Nanonoscience

“…The difficulty of preparing polyphosphazene containing anchored silicon groups has been pointed out by Allcock et al [49][50][51][52][53][54][55]. Previous attempts [55].…”

Reaction of N-[chloro(diorganyl)silyl]anilines with isopropanol and isopropylamine

“…N-Silylamines have found wide application in organic synthesis as synthons [1][2][3][4][5] and silylating agents [6][7][8][9] as well as in the material science as precursors for preparation and modification of polymer materials [10][11][12][13], protecting films [14,15], and advanced materials based on silicon nitride and oxynitride [16][17][18][19][20]. The first reports on synthesis of polyfunctional silanes of the general formula R 1 R 2 Si· (Cl)NR 1 R 2 (R 1 , R 2 = H, Alk, or Ar) date back to the second half of the XX century [20][21][22][23][24][25], and some data on their chemical properties have been published [26,27].…”