The main reactions, described hereinafter, are polyaddition of vinyl groups
, radical reactions of methyl and vinyl groups
, hydrosilylation, dehydrogenations and transamination.
This resulted in a surface containing vinyl groups
. The vinyl-coated nanocomposite particles were further modified with acrylic acid via an inverse emulsion polymerization resulting in polymer-magnetic support material (Scheme 2).
The silane agent adopted in this study has a reactive vinyl group
and a hydrolyzed trialkoxysilane.
Using proton nuclear magnetic spectroscopy [(.sup.1)] H NMR), it was determined that 100% of the vinyl groups
were converted to epoxy groups.
The increase of particle size (Table 5) was primarily due to branching caused by grafting of vinyl group
of ATBS onto polyester backbone of MOD 1.
At 99% MA conversion, the final molecular weight in SET-LRP polymerization ([M.sub.w.MALLS] = 86,400 g [mol.sup.-1]) was much larger than that in ATRP ([M.sub.w MALLS] = 61,400 g [mol.sup.-1]) due to higher focal vinyl group
The polymer D has an active vinyl group
at every side chain.
PDMS (vinyl group
content of 10 mol% and a number-average molecular weight of 500,000 g/mol) and a chloroplatinic acid solution (as a catalyst) were obtained from the Research Center of Organic Silicone of Chengdu, China.
Solid state [.sup.13]C NMR showed two resonance at [delta] 131 ppm and [delta] 138 ppm attributed to the vinyl group
(--CH=C[H.sub.2]--) of VTMS and solid-state [.sup.29]Si-NMR revealed the resonance at [delta]--110 ppm and [delta]--100 ppm corresponding to the Si[(OSi).sub.4] ([Q.sup.4]) and Si[(OSi).sub.3]0H ([Q.sup.3]) environments in colloidal silica, respectively (32), (33).
When compared with the original HTV SR gum (A), there is hardly any change in the typical peaks of the vinyl group
between the two samples, indicating that the initiators definitely did not initiate the curing reaction of the HTV SR/BP2000 composite.
For the ETOS and VTOS, their sizes are similar, but the vinyl group
is more polarized than the ethyl.
It was also found that hydrosilane reacts more rapidly with a vinyl group
than with a hydroxy group.