PLLA-PDLA Elastomer Composition With Stereocomplex Heat Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rubber compositions for tires lack a material with high thermal and mechanical properties that can be produced through a continuous, flexible, and cost-effective process, while also exhibiting thermoplastic elastomer properties.
Innovation Solution
A rubber composition comprising a mixture of poly-L-lactide (PLLA) and poly-D-lactide (PDLA) diene elastomers, where one is block covalently bonded to a diene elastomer and the other as a homopolymer, forming a stereocomplex with a melting point greater than 150°C, achieved through reactive extrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a mixture comprising PLLA and PDLA is used to form a stereocomplex with higher melting point, then thermal properties are improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines PLLA and PDLA in specific ratios (20:80 to 80:20) to form a stereocomplex mixture that achieves higher melting point (150-250°C) while maintaining manufacturability through reactive extrusion processing
Solution Approach 2:
The patent optimizes the compositional parameters of PLLA/PDLA ratios and controls the polymerization conditions during reactive extrusion to achieve the desired melting point range while keeping the manufacturing process feasible
2Reliability
If diene elastomer/polylactide copolymers with thermoplastic elastomer properties are synthesized, then material performance is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent uses a diene elastomer as an intermediary component that is covalently bonded to polylactide blocks, creating a copolymer that bridges the properties of elastomers (elasticity) and thermoplastics (meltable structure), enabling both high performance and continuous processing
Solution Approach 2:
The patent creates a composite material system where diene elastomer and polylactide are chemically bonded to form a copolymer with integrated properties of both components, achieving thermoplastic elastomer behavior suitable for continuous manufacturing
3Productivity
If continuous manufacturing process like reactive extrusion is used, then productivity is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent implements continuous reactive extrusion processing where monomers are polymerized and copolymers are formed in a continuous flow through the extruder, maintaining steady-state conditions that ensure consistent product quality while maximizing productivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition exhibits enhanced thermal and mechanical properties, including high deformation before breaking and a rubbery plateau over a broad temperature range, making it suitable for tire applications while being cost-effective and manufacturable through continuous processes.
Implementation Method 1
PDLA and PLLA may together form a stereocomplex having a higher melting point than that of PLLA alone or PDLA alone
Implementation Method 2
the ability to reversibly melt and harden under the action of heat, of the polylactide blocks
Implementation Method 3
a diene elastomer block covalently bonded to at least one polylactide block
Data Source
AI summary
An elastomeric mixture comprises at least: one diene elastomer/polylactide copolymer A1 comprising a polylactide block PLLA or PDLA, where appropriate one or more other polylactide blocks which are all PLLA when the first block is PLLA or which are all PDLA when the first block is PDLA, the mass percentage of the polylactide block(s) being between 10% and 50% by weight relative to the weight of the copolymer A1, and a diene elastomer/polylactide copolymer B1 the mass percentage of the polylactide block(s) in said copolymer B1 being between 10% and 50% by weight relative to the weight of the copolymer B1, or a polylactide B2, or a mixture of said copolymer B1 and of said polylactide B2, the names PLLA and PDLA denoting a chain consisting of units of formula (I) —[CH(CH3)—C(O)—O]— (I), of which at least 70% by weight are, respectively, of L and D configuration.