In general, not only the inherent brittleness, but also low thermal resistance are limitations in PLA applications. In the current study, PLA was chemically bonded in situ with highly crystalline PBS chains through SA condensa- tion, to enhance the thermal dimensional stability of PLA. The percentage of thermal shrinkage was simply determined by changing the film dimensions along MD and TD after annealing at high temperatures, as shown in Table 2.The PLA film shrank slightly (around 5%) in both MD and TD after annealing at 60C for 60 min. This sug- gested that some free amorphous PLA chains deformed and were rearranged into higher-order structures near Tg. The shrinkage of the PLA film was extreme with $10% in MD and $20% in TD when annealed at 100C (Tcc)