1. Introduction 2. Terminology and dimensions of sustainability, life cycle assessment, and characteristics of sustainable polymer materials 3. Science and technology of polylactide 4. Synthesis, properties, advantages, and challenges of bio-based and biodegradable polymers used for the preparation of blends with polylactide 5. Fundamentals of polymer blend technology 6. Processing technologies for polylactide-based blends 7. Techniques for structural and morphological characterization of polymer blends 8. Mechanical models for polymer blends 9. Polylactide stereocomplex 10. Polylactide/natural rubber blends 11. Polylactide/starch blends 12. Polylactide/chitosan blends 13. Polylactide/poly(hydroxyalkanoate) blends 14. Polylactide/lignin blends 15. Polylactide/natural oil blends 16. Polylactide/poly(butylene succinate) blends 17. Polylactide/poly[(butylene succinate)-co-adipate] blends 18. Polylactide/poly(e-caprolactone) blends 19. Polylactide/poly(butylene adipate terephthalate) blends 20. Market, current and future applications 21. Conclusions, challenges, and future outlook