Preparation and characterization of polylactide-block-poly(butylene adipate) polyurethane thermoplastic elastomer

• Published in: Polymer engineering and science Vol. 51; no. 5; pp. 908 - 916
• Main Authors: Zhong, Qian, Ren, Jie, Wang, Qinfeng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.05.2011; Wiley; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Blocking; Chemical properties; Composition; Crystallinity; Diols; Elastomers; Exact sciences and technology; High temperature; Identification and classification; Mechanical properties; Molecular structure; Molecular weight; Organic polymers; Phase separation; Physicochemistry of polymers; Polycondensation; Polymerization; Polyurethane; Polyurethanes; Preparation, kinetics, thermodynamics, mechanism and catalysts; Production processes; Thermoplastic elastomers; Thermoplastics; China; Lactone copolymer; Lactic acid copolymer; Mechanical properties; Thermoplastic rubber; Crystallinity; Experimental study; Polyaddition; Tensile strength; Polyurethane elastomer; Thermal properties; Ester copolymer; Esterurethane polymer; Multiblock copolymer; Preparation; Property structure relationship; Adipate copolymer
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.21911

Polylactide‐block‐poly(butylene adipate) poly(ester‐urethane) (PLAEU) thermoplastic elastomer was obtained by melt chain extending reaction with polylactide‐block‐poly(butylene adipate)‐block‐polylactide (PBLA) and hexamethylene diisocyanate (HDI). PBLA was previously prepared with L‐lactide and poly(butylene adipate) diol (PBA diol). Experimental parameters including feed ratio, polymerization temperature, and time were optimized. The weight average molecular weight (Mw) of PLAEU surpassed 105 g/mol. In contrast to corresponding PBLA, the crystallinity and melt temperature (Tm) of PLAEU decreased, whereas its glass transition (Tg) shifted to high temperature due to the “pseudoextension” structure of polylactide (PLA) block. Additionally, the crystallinity and Tm of PLAEU were subject to crystallization method and molecular weight. The tensile strength of PLAEU varied from 6.61 to 24.41 MPa and elongation from 190% to 780%. Therefore, the mechanical properties of PLAEU can be regulated by altering the length ratio of PLA to PBA block. The high elasticity of PLAEU can be explained with phase separation mechanism. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers