Related Experiment Video
Updated: Aug 1, 2025
11:42
Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
7.9K
A Relatively Simple Look at the Rather Complex Crystallization Kinetics of PLLA.
Jorge López-Beceiro1, Ana-María Díaz-Díaz1, Enrique Fernández-Pérez1
1Centro de Investigación en Tecnoloxías Navais e Industriais (CITENI), Campus Industrial de Ferrol, Universidade da Coruña, 15403 Ferrol, Spain.
Polymers
|April 28, 2023
Summary
This study reveals a simple method to observe poly(L-lactic acid) (PLLA) complex crystallization kinetics. A two-component kinetic model accurately describes the coexistence of α and α
Area of Science:
- Polymer Science
- Materials Science
- Crystallization Kinetics
Background:
- Poly(L-lactic acid) (PLLA) crystallization is complex, with existing studies focusing on various aspects.
- Understanding PLLA's crystallization behavior is crucial for its applications.
Purpose of the Study:
- To present a simple method for observing PLLA's complex crystallization kinetics.
- To propose and validate a two-component kinetic model for PLLA crystallization.
Main Methods:
- X-ray diffraction (XRD) to analyze crystal structures (α and α' forms).
- Differential Scanning Calorimetry (DSC) for exothermic peak analysis.
- Deconvolution of DSC peaks using two logistic derivative functions.
Main Results:
- PLLA crystallizes in both α and α' forms, coexisting over a range of temperatures.
- The predominance of each crystal form is temperature-dependent.
- A two-component kinetic model effectively reproduces the overall crystallization process.
Conclusions:
- A novel, simple method can reveal complex PLLA crystallization kinetics.
- The proposed two-component model accurately captures the simultaneous crystallization of α and α' forms.
- This approach may be applicable to other polymer isothermal crystallization processes.
More Related Videos
Related Concept Videos
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
01:26Polymer Classification: Stereospecificity
2.5K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.5K
01:08Molecular Weight of Step-Growth Polymers
2.3K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.3K
01:03Step-Growth Polymerization: Overview
3.6K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
3.6K
01:10Recrystallization: Solid–Solution Equilibria
1.1K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.1K
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
3.4K
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta...
3.4K