Ether chain type crosslinks

Table 1 shows the relative concentration of the possible acetal moieties of the PHSVC reaction with various vinyl ethers. Besides the acetal protected OH groups B and C (scheme 3), two different structural units D and E were identified by C-NMR analysis (42), The structural unit E is only observed with t-butyl vinyl ether. However, no aromatic to aromatic intra and inter chain crosslinking (F in scheme 3) was observed in either the PHS or PHSVC system, unless high catalyst concentration or high temperature was used. Not only the type of vinyl ether units influenced the molecular weight but also the amoimt of die vinylcyclohexanol comonomer ratio in PHSCV. 

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