Identifying design criteria for ethylene glycol-based methacrylate thermoresponsive polymer
File(s)
Author(s)
Li, Qian
Type
Thesis
Abstract
Thermoresponsive hydrogel (TRG) is a 3-D network formed by thermoresponsive polymers
through physical or chemical crosslinks. Due to its unique temperature-triggered sol-gel
transition, TRG with a gelation point (Tgel) around body temperature has gained significant
interest in biomedical applications, such as injectable gel, tissue engineering, 3-D bioprinting,
etc. Among all the thermoresponsive polymers, polymers based on oligo(ethylene glycol)
methyl ether methacrylate (OEGMA) are of great interest because they exhibit a lower critical
solution temperature (LCST) in a wide temperature range (from room temperature to above
90°C) and are non-ionic monomers that do not interrupt the pH of body fluids. This thesis
successfully synthesizes OEGMA-based polymers via Group Transfer Polymerization (GTP)
and systematically investigates their thermoresponsive properties. Additionally, this thesis
explores how these polymers influence the thermoresponsive behaviour of Pluronic® F127, a
well-known commercial TRG system composed of a triblock copolymer with an approximate
molecular mass (MM) of 12500 g mol-1
, based on poly(ethylene oxide) (PEO) and
poly(propylene oxide) (PPO) segments.
The first study (Chapter 5) investigates the thermoresponsive behaviour of homopolymers
based on OEGMA monomers. In total, 31 homopolymers were successfully synthesized and
systematically compared. It was found that the end group of the side chain has a more
prominent effect on the thermoresponsive behaviour of these homopolymers than the number
of EG groups on the side chain and the MM.
The following chapters (Chapter 6 and 7) investigate the possibility of building a TRG system
of diblock polymers based on OEGMA. Specifically, MEGMA, DEGMA, and PEGMA [mono,
di, and penta(ethylene glycol) (OEG) (m)ethyl ether methacrylate] were chosen. A TRG system
with Tgel at around 48°C was built for the first time based on PEGMA-b-MEGMA diblock
polymers. Some of the PEGMA-b-MEGMA diblock polymers were also found to exhibit an
interesting spherical to worm-like micelle transition upon heating. The polymers synthesized
in these two chapters were further investigated as polymeric additives to Pluronic® F127.
Among all the diblock polymers synthesized in these chapters, a mixture of PEGMA-b DEGMA diblock polymer and Pluronic® F127 was found to undergo a sol-gel transition from
37°C and has shown good potential for biomedical applications.
through physical or chemical crosslinks. Due to its unique temperature-triggered sol-gel
transition, TRG with a gelation point (Tgel) around body temperature has gained significant
interest in biomedical applications, such as injectable gel, tissue engineering, 3-D bioprinting,
etc. Among all the thermoresponsive polymers, polymers based on oligo(ethylene glycol)
methyl ether methacrylate (OEGMA) are of great interest because they exhibit a lower critical
solution temperature (LCST) in a wide temperature range (from room temperature to above
90°C) and are non-ionic monomers that do not interrupt the pH of body fluids. This thesis
successfully synthesizes OEGMA-based polymers via Group Transfer Polymerization (GTP)
and systematically investigates their thermoresponsive properties. Additionally, this thesis
explores how these polymers influence the thermoresponsive behaviour of Pluronic® F127, a
well-known commercial TRG system composed of a triblock copolymer with an approximate
molecular mass (MM) of 12500 g mol-1
, based on poly(ethylene oxide) (PEO) and
poly(propylene oxide) (PPO) segments.
The first study (Chapter 5) investigates the thermoresponsive behaviour of homopolymers
based on OEGMA monomers. In total, 31 homopolymers were successfully synthesized and
systematically compared. It was found that the end group of the side chain has a more
prominent effect on the thermoresponsive behaviour of these homopolymers than the number
of EG groups on the side chain and the MM.
The following chapters (Chapter 6 and 7) investigate the possibility of building a TRG system
of diblock polymers based on OEGMA. Specifically, MEGMA, DEGMA, and PEGMA [mono,
di, and penta(ethylene glycol) (OEG) (m)ethyl ether methacrylate] were chosen. A TRG system
with Tgel at around 48°C was built for the first time based on PEGMA-b-MEGMA diblock
polymers. Some of the PEGMA-b-MEGMA diblock polymers were also found to exhibit an
interesting spherical to worm-like micelle transition upon heating. The polymers synthesized
in these two chapters were further investigated as polymeric additives to Pluronic® F127.
Among all the diblock polymers synthesized in these chapters, a mixture of PEGMA-b DEGMA diblock polymer and Pluronic® F127 was found to undergo a sol-gel transition from
37°C and has shown good potential for biomedical applications.
Version
Open Access
Date Issued
2023-04
Date Awarded
2023-07
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Georgiou, Theonitsa
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)