Can our bodies create antibodies against synthetic materials

Absolutely. A really good example of this is polyethylene glycol (PEG). PEG is used for a vast number of aesthetic and drug compounds. Many people now have anti-PEG antibodies in their bodies, whereas a few decades ago, we did not. Also, drug manufacturers create antibody drugs for a myriad of applications. Our bodies even generate antibodies against these antibodies, which are called anti-drug antibodies (ADAs).