Seeking advice promissory note

[Lawrence Barnes]

Hello Biggerpockets family!

I have two investor friends that have acquired an 18-unit apartment complex under sub-to the existing mortgage. The property is in the name of an LLC. They need 10k to pay off property taxes owed on property.

If I give them the 10k, I will have a 1/3 interest in the apartment complex. Of course I will have a business agreement in place stating this.

I want to lend the 10k on terms and would like to receive monthly payments until the complex is performing at a certain standard. 

Here are my questions:

Can I legally have a promissory note with the LLC that has a promise to pay a certain amount monthly and still be a member of the same LLC?

If so, would anyone have a base template of a promissory note that would be good to use?

Thank you in advance BP family, any advice is greatly appreciated.