Examine the forces keeping Holden in childhood. Please help me with quotes and chapters. Many thanks.

The primary force keeping Holden in childhood is fear of growing up to become a phony like many of the adults he knows. He sees a certain amount of purity and innocence in childhood that he wishes to preserve. Here are a few examples:
The phoniness of adults:

Chapter 1. To Holden, his brother D.B. is a "prostitute" for going to Hollywood to make money writing movies when he could have stayed a short story writer.

Chapter 1. While meeting with Old Spencer, Holden becomes angry when his former teacher calls him out on his lack of effort in class and reads Holden's test out loud. He says he doesn't think he'll "ever forgive him for reading . . . that crap out loud." In addition, he says Spencer's use of the word "grand" is "a phony" and could make Holden "puke every time I hear it."

Chapter 24. Holden goes to stay with Mr. Antolini because Holden feels that his old English teacher could understand him, particularly his dislike of D.B. going to Hollywood to work in the movies. However, his trust in Antolini disappears when he wakes up to find his old English teacher rubbing his head in a "perverty" way.
The preservation of innocence:

Chapter 16. This chapter is probably the most important in the novel thematically. The museum, one of the primary symbols of the novel, stands for Holden's desire to preserve childhood. While thinking about looking for his sister Phoebe in the Museum of Natural History, Holden thinks about what he likes about the place. He says that "[t]he best thing . . . in that museum was that everything always stayed right where it was. . . . The only thing that would be different is you."

Chapter 22. In this chapter, Holden explains the novel's title. He says he would want to be "the catcher in the rye" from the Robert Burns poem by the same name. He says he keeps "picturing all these little kids playing some game in this big field of rye and all. . . . What I have to do, I have to catch everybody if they start to go over the cliff." Ironically, Burns's poem is about lovers meeting in a field of rye to have sex, one of the actions Holden sees as a true sign of adulthood and phoniness.