4. Conclusion
By studying the hydrolytic degradation of PLA and PLA/NR blends in deionized water at 58 C, and measuring the contact angle and water absorption, the average molecular weight and mass, as well as the morphology and thermal property of the samples, the effect of NR on the hydrolysis of PLA has been revealed. Though NR can enhance the hydrophobility of the surface of PLA, it does not cause a decrease in water absorption in the bulk of PLA probably because of the bigger intermolecular distance of NR than PLA. Both neat PLA and PLA/NR blends process hydrolysis by bulk erosion mechanism and the hydrolysis rate of PLA is not affected by NR, having no observable effect of NR on the hydrolysis of PLA. The
results will be beneficial for keeping the biodegradability of PLA when toughened by NR and hence for applying the PLA/NR materials in practical fields.