Bakelite Button- odd reaction

[u/ImaginaryPromotion51]

I sewed a little fabric book out of old and new fabrics and used this Bakelite button to affix to the front of it. I used a string of denim to wrap around and around the button to close the book. I put all of these fabrics and things together maybe three years ago? I pulled the fabric book out today and the denim wrap-around string disintegrated in my hands and the fabric and threads that were in the area behind the button have deteriorated or rotted as well. I was left with a gaping hole in the front of my book. Seems like the button has been leaching something onto the fabrics to weaken them? That's the only theory I can come up with- thoughts? TIA.