[vadevalor]

non-ionic detergents can be made by reaction of epoxyethane,in an excess,with a C11 alcohol.

A possible mechanism involves homolytic fission of a C-O bond in epoxyethane giving rise to a double ended free radical that initiates a chain reaction.The first propagation step is as follows:

.CH2-CH2-O  +epoxyethane  (H2C-CH2-O where this O is linked backed to CH2)   --> .CH2-CH2-O-CH2-CH2-O.
(Where . represents a free radical)

After termination of the reaction with alcohol,what is a possible formula of such a non-ionic reagent?
A. (CH3(CH2)10 O)10 CH2CH2OH
B. CH3(CH2)10 O (OCH2CH2)10 OH
C.CH3(CH2)10 O (CH2CH2O)10 H
D. CH3(CH2)10 O (CH2CH2O)10 OH

Please explain this mechanism to me! i know alkanes undergo free radical substitution,but after looking at this i dont know which acts like the halogen in free radical substitution.
Also,if it is substitution then why does the propagation step given seem like an addition reaction? (nothing is kicked out in that sense)
If an answer is correct,why are the others wrong?

[orgopete]

The propagation reaction is not like the halogenation reaction. In halogenation, a hydrogen atom is transferred and in this reaction that does not happen.

In order to write a mechanism, it might be easier to form the initiating radical with the C11-alcohol. In this case, it may be easier to abstract a hydrogen atom. Then initiation and termination would be related. The polymerization reaction should be a repeating step.

[vadevalor]

so this is a polymerisation reaction? i'm confused. if the double ended radical is supposed to react with the C11 alcohol then why does the propagation step shown state that it react with epoxyethane? I tried to add the C11 alcohol with the double ended radical,but the answers all have more than 20 Carbons how do they add to that much carbons?

[orgopete]

Rather than reacting a diradical, assume the C11 alcohol forms RO• + H•. React the RO• with the ethylene oxide. This should give a new R'O•. If this continues to react with ethylene oxide, it will be a polymerization propagation step. Now, if this radical should react with the H•, it will be a termination step. If the R'O• reacts with ROH, it will terminate one chain and begin another.

I do not know this chemistry. I don't know what initiator was used for this reaction. I would guess it is an oxidant to catalyze a reaction as this: (I couldn't put the O in brackets.)
2ROH + "O"  ROOR + H2O

Then the initiation reaction would be
ROOR + heat/light  2RO•

If someone knows these reactions, please correct me.