Efficient way to synthesize poly(alkyl)amine

I am trying to synthesize poly(ethylene-propylene)amine, i.e.:


[![enter image description here](https://i.stack.imgur.com/CawVj.png)](https://i.stack.imgur.com/CawVj.png)


I've read that [Reductive Amination](https://www.masterorganicchemistry.com/2017/09/01/reductive-amination/) is efficient regarding the reaction yield. However, it needs aldehydes to start the reaction. To make the aldehydes I can use [this way](https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Aldehydes_and_Ketones/Synthesis_of_Aldehydes_and_Ketones/Preparation_of_Aldehydes_and_Ketones) and start from the hydroxyl-terminated polymer compound. I reach to a dilemma here where my experience is not enough to decide which way to go. I can start with a aldehyde-terminated polymer at first so I don't have to make it from an OH-terminated polymer. 


Which way do you suggest? A reference on how to do the one you recommend is also appreciated.




Before I offer an answer understand that I am a general synthetic chemist used to working in solution phase, and I have not worked with polymers. Absent an answer from someone who has here is how I would tackle this using OH-terminated polymer.


1 -reaction with methanesulfonyl chloride/triethylamine to activate the -OH for displacement. This is known as mesylation [more here](http://commonorganicchemistry.com/Rxn_Pages/Alcohol_to_Sulfonic_Ester/Mesylate/Mesylate_Index.htm) and [here](https://www.masterorganicchemistry.com/2015/03/10/tosylates-and-mesylates/)


2- reaction with sodium azide in DMF or DMSO to give the alkyl azide


3- reduction of the alkyl azide to the amine with triphenyl phosphine [Staudinger reduction](https://www.sciencedirect.com/topics/chemistry/staudinger-azide-reduction)


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