Fractional distillation of a product differs from the components listed in the SDS. What am I doing wrong?
Best Answer is this:
Your observations are consistent with the SDS for the reasons below. 

A couple of issues see below.


Fractional distillation is much more complicated than you suppose. You have no way to control reflux ratio, (amount of distillate vs reflux) which right away will limit your separation. The column is not insulated or temperature controlled. 
Vigreux columns are good for distilling one component from non-volatiles, but are not made for fractional distillations. You will need a much more efficient column, the cheapest choice being a vacuum jacketed Hempel column with some sort of packing, ie Raschig rings. 
With the equipment you are using, a range of 10 C between ideal boiling points would be considered normal, you will not see the sharp cut offs you are expecting. 
The first component is likely methanol, and the boiling point range you are seeing is due to the above reasons. 
Ethylene glycol does not boil to almost 200 C, when you end the distillation, is there any liquid left in the distilling flask? 
As far as I could quickly check, methanol and ethylene glycol do not form an azeotrope, but the tables I checked were on Wikipedia and not thorough, you might want to check that. The formation of an azeotrope definitely explains the observations especially if it boils in the range of 98C +/- 20 C
Not sure on the exact conditions or if the MSDS is wrong, but it is conceivable dimethoxyethane (dimethyl glycol) formed or was the original constituent, this has a boiling point of 85 C, it could have even formed in the distilling flask depending on conditions. 
Note the MSDS or SDSs are they are now called are not complete, and there are usually other minor constituents that might appear and could possible catalyze the formation of dimethoxyethane, assuming the SDS was correct in the first place. 
Distillation is not the appropriate method here, GC-MS would be the way to go. 


Hope that helps! I suggest you purchase Handbook of Laboratory Distillation, it is the fundamental text for distillation in theory and practice, the price is well worth it. 

In conclusion your observations could be explained by: azeotrope formation, incorrect SDS, formation of dimethoxyethane, and incorrect set up.