Chain Branching 厘 H 日日H middle of a polyethylene chain growing end of a chain chain with 2 free radical terminated chain (I free radical) in the middle HC=CH2 growing branch CH2-CH, HH H new chain growing original chain at the branch point Copyright2010 Pearson Prentice Hall,Inc. Chain branching occurs when the growing end of a chain abstracts a hydrogen atom from the middle of a chain.A new branch grows off the chain at that point. Chain branching makes the polymer soft. Chapter 26 7Chapter 26 7 Chain Branching ▪ Chain branching occurs when the growing end of a chain abstracts a hydrogen atom from the middle of a chain. A new branch grows off the chain at that point. ▪ Chain branching makes the polymer soft