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Long-Chain Bio-Based Nylon 514 Salt: Crystal Structure, Phase Transformation, and Polymerization
Zihan Li1, Lei Zhang2, Xiaohan Zhang1
1National Engineering Technique Research Center for Biotechnology, State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Polymers
|February 24, 2024
Summary
This study details the crystal structures and thermal stability of nylon 514 monomers, identifying anhydrous and dihydrate forms. Stable dihydrate powders were used to produce high-performance nylon 514 with improved thermal properties and low absorption.
Area of Science:
- Materials Science
- Polymer Chemistry
- Crystallography
Background:
- Nylon 514 is a novel long-chain, bio-based nylon derived from 1,5-pentanediamine (PDA) produced via biotechnological routes from biomass.
- The monomer salt, 1,5-pentanediamine-tetradecanedioate (PDA-TDA), is crucial for nylon 514 synthesis.
Purpose of the Study:
- To identify and characterize different crystalline forms of the PDA-TDA monomer.
- To investigate the relationship between crystal structure, thermal behavior, and stability of PDA-TDA.
- To optimize the production of high-performance nylon 514 using stable monomer forms.
Main Methods:
- Efficient crystallization techniques to obtain PDA-TDA salt.
- X-ray diffraction and thermal analysis (DSC/TGA) for crystal structure and behavior determination.
- Hirshfeld and IRI analyses to quantify intermolecular interactions and lattice energy calculations.
Main Results:
- Two crystal forms of PDA-TDA, anhydrous and dihydrate, were identified and structurally characterized.
- The study established the transformation mechanism between anhydrous and dihydrate forms, highlighting the role of temperature and water activity.
- Nylon 514 synthesized using stable dihydrate monomers exhibited excellent thermal stability and low moisture absorption.
Conclusions:
- The dihydrate form of PDA-TDA is a stable monomer suitable for producing high-performance nylon 514.
- Understanding crystal polymorphism and stability is key to optimizing bio-based nylon production.
- Bio-based nylon 514 offers promising properties for advanced material applications.
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