Mechanistic Aspects of 1,3,5-Trioxane Polymerization Pertinent to Polymer Synthesis

5 Mechanistic Aspects of 1,3,5-Trioxane Polymerization Pertinent to Polymer Synthesis 

In spite of hundreds of papers describing the phenomenology of TXN homopolymerization and TXN-DXL copolymerization (rates, Mn) on polymerization variables (cf. for example Refs. 24 48-58)), little is known as to the elementary reactions involved. Progress was hampered by the insolubility of the polymer and crystallization that occurs during polymerization. Another difficulty is the complexity of thermodynamics of TXN polymerization. 

This section is. not an exhaustive review of all of the papers published instead we will try to present a coherent view of cationic TXN polymerization needed to comprehend phenomena taking place during polymer synthesis. 

Boron trifluoride in form of its complexes is commonly used as the initiator of TXN polymerization. The existing hypotheses concerning the initiation mechanism may be divided into two categories a) direct initiation  

Kern and Jaacks, who first studied this problem thoroughly, expressed the opinion that the polymerization of TXN can be initiated by BF3 even in the absence of pro-togenic compounds 54). Later, on the basis of new observations, they weakened their position and concluded that it was impossible to decide whether initiation can occur in the absence of coinitiator 55). 

---