Sulfur-nitrogen-phosphorus-containing polymers

Handbook of Ring-Opening Polymerization. Edited by P. Dubois, O. Coulembier, and J.-M. Raquez 

Copyright 2009 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-31953-4 

Mechanism and Methods in Ring-Opening Polymerization (ROP) of Halc enated Cyclotriphosphazenes 

Contemporary to this review were studies examining the mechanism of the polymerization performed both, with and without, added catalysts. The reaction 

An additional interesting observation was the observed fivefold increase in reaction rate observed in bulk polymerizations, as opposed to solution. Taking into consideration the densities of the respective systems, and considering the catalyst loading on a volumetric basis instead of a weight basis, gives an only two- to threefold increase in the rate of the bulk system. From this, the authors proposed that an aprotic benzene solvent played no significant role in the polymerization mechanism. 

---

Part 2 includes chapters on specific classes of cyclic monomers and their polymerization mechanisms and kinetics, their main (co)polymer architectures and related products, as well as current and future applications. Hence, siloxane-con-taining and sulfur-nitrogen-phosphorus-containing polymers are described in Chapters 3 and 4, respectively, while the polymerization of cyclic depsipeptides, ureas and urethanes, of polyethers and polyoxazolines, and of polyamides are detailed in Chapters 5, 6 and 7, respectively. Chapters 9, 10, 11 and 12 include details of polyesters prepared from either P-lactones, from dilactones, from larger lactones and from polycarbonates, while the polymerization of cycloalkanes is described in Chapter 13. It should be noted that, slightly out of place . Chapter 8 covers the subject of ring-opening metathesis polymerizahon. 

The previous example illustrates that quantification on entirely polymeric systems is difficult to achieve and often requires elaborate post-modification steps. XPS analysis, however, can provide straightforward information on the presence of hetero-atoms from the graft polymer (e.g., phosphorus, nitrogen, and sulfur) if the substrate polymer does not contain these elements. Moreover, complexation of metal cations such as Fe ", Ni ", and Cu " can also be investigated. XPS is therefore complementary to other analysis techniques, such as UV spectroscopy and ATR-IR spectroscopy. 

HPLC is one of the most universal methods for determining the enantiomeric composition of substances and mixtures in a short time frame. Its application is not restricted to molecules in which chirality is based on a quaternary carbon atom with four different substituents it can also be employed for compounds containing a chiral silicon, nitrogen, sulfur, or phosphorus atom. Likewise, asymmetric sulfoxides or aziridines, the chirality of which is based on a lone electron pair, can be separated. Chirality can also be traced back to helical structures, as in the case of polymers and proteins to the existence of atropiso-merism, the hindered rotation about a single bond, as observed, for example, in the case of binaphthol, or to spiro compounds. 

Cyclic monomers that have been polymerized via ring-opening encompass a variety of structures, such as alkanes, alkenes, compounds containing heteroatoms in the ring oxygen [ethers, acetals, esters (lactones, lactides, and carbonates), and anhydrides], sulfur (polysulfur, sulfides and polysulfides), nitrogen [amines, amides (lactames), imides, N-carboxyanhydrides and 1,3-oxaza derivatives], phosphorus (phosphates, phosphonates, phosphites, phosphines and phosphazenes), or silicon (siloxanes, silaethers, carbosilanes and silanes). For the majority of these monomers, convenient polymerization conditions have been elaborated, that result in the controlled synthesis of the corresponding polymers [1-13]. 

---