Going from a PVC Sched 40 1-1/2" PIPE to a 1/2" Poly Combination Elbow
They make the same type of bushing that you used before, but in PVC. It would be called an 1 1/2" x 1/2" slip x FIP bushing. "FIP" means female iron pipe.



This picture is actually 1" FIP, which will be easier to find than 1/2", and also easy to "bush" down to smaller sizes using threaded brass bushings: