Synthesis and Melt Processing of Sustainable Poly(蔚-decalactone)-block-Poly(lactide) Multiblock Thermoplastic Elastomers

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• 作者：Mark T. Martello ; Deborah K. Schneiderman ; Marc A. Hillmyer
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2014
• 出版时间：November 3, 2014
• 年：2014
• 卷：2
• 期：11
• 页码：2519-2526
• 全文大小：341K
• ISSN：2168-0485

文摘

A one-pot, one-catalyst, sequential ring-opening transesterification polymerization (ROTEP) was used to prepare fully renewable amorphous poly(d,l-lactide)鈥損oly(蔚-decalactone)鈥損oly(d,l-lactide) (LDL) triblock polymers. These 伪,蠅 hydroxy-telechelic polymers were subsequently coupled to prepare linear alternating (LDL)_n multiblock polymers. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) indicated microphase separation into two domains in both the triblock and multiblock architectures. The temperature dependent Flory鈥揌uggins interaction parameter for this system, 蠂(T) = 69.1/T 鈥?0.072, was estimated from the experimentally determined order鈥揹isorder transition temperature (T_ODT) values of four symmetric LDL triblock polymers. Uniaxial extension tests revealed a dramatic dependence of the room-temperature mechanical properties on overall molar mass. Additionally, coupling low molar mass LDL triblocks to prepare (LDL)_n multiblocks led to substantial increases in the ultimate elongation and tensile stress at break. Compared to high molar mass triblocks with inaccessible T_ODT values, (LDL)_n multiblocks of similar composition and molar mass were found to disorder at much lower temperatures (T_ODT < 150 掳C). Because of this, it was possible to process (LDL)_n using injection molding. The simple synthetic procedure and melt processability of the (LDL)_n multiblock polymers make these multiblocks attractive as renewable thermoplastic elastomers (TPEs).

Keywords:

Injection molding; Melt polymerization; Interaction parameter; Mechanical properties; Block polymers