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Bone-tissue-engineering material poly(propylene fumarate): correlation between molecular weight, chain dimensions,
Shanfeng Wang1, Lichun Lu, Michael J Yaszemski
1Tissue Engineering and Polymeric Biomaterials Laboratory, Department of Orthopedic Surgery, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA.
Biomacromolecules
|June 14, 2006
Summary
This study extensively characterizes poly(propylene fumarate) (PPF), a biodegradable polymer for bone tissue engineering. Findings reveal how molecular weight influences PPF
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Biomedical Engineering
Background:
- Poly(propylene fumarate) (PPF) is a key biodegradable polymer for bone tissue engineering.
- Understanding PPF's physical properties is crucial for optimizing its biomedical applications.
Purpose of the Study:
- To comprehensively characterize poly(propylene fumarate) (PPF).
- To investigate the molecular weight dependence of PPF's physical and microstructural properties.
- To correlate chain microstructure with macroscopic physical characteristics for enhanced biomedical use.
Main Methods:
- Rheological characterization to determine melt viscosity and plateau modulus.
- Analysis of molecular weight effects on glass transition temperature (Tg), thermal degradation (Td), density (rho), and hydrodynamic radius (RH).
- Deduction of chain microstructure parameters including Mark-Houwink-Sakurada constants and Kuhn length.
Main Results:
- Established molecular weight dependencies for Tg, Td, rho, eta0, RH, and [eta].
- Unified temperature dependence of melt viscosity by normalizing to Tg.
- Obtained plateau modulus and entanglement molecular weight (Me) from rheological master curves.
- Deduced various chain microstructure parameters (K, alpha, Cinfinity, r0(2)/M, p, b, a).
- Demonstrated Me's irrelevance for finite length effects on Tg.
- Identified inherent chain properties (fragility, cooperativity, end mobility) as key factors influencing Tg.
Conclusions:
- Provided extensive characterization of PPF, linking molecular weight to physical properties.
- Advanced understanding of polymer dynamics in unsaturated polyesters for biomedical applications.
- Highlighted the critical role of intrinsic chain properties in governing the glass transition behavior of PPF.
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