活性自由基聚合,EMPO
合集下载
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2020/9/18
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
R·,Y·活泼自由基，则产物有三种, 1:2:1。 R·活泼自由基，Y·persistent radical, 产物只有一种
2020/9/18
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
N O
polystyreneCH2 CH
Polymerization Systen: Monomer: Styrene Initiator: BPO Additive: TEMPO
Conditions: Initial heating at 95oC for 3.5h, followed by heating at 123oC for 69h. Results: Narrow molecular weight polystyrene with polydispersity of 1.26. The number-average molecular weight increased linearly with with monomer conversion.
Polymerization Systen: Monomer: Styrene Initiator: BPO Additive: TEMPO
Conditions: Initial heating at 95oC for 3.5h, followed by heating at 123oC for 69h. Results: Narrow molecular weight polystyrene with polydispersity of 1.26. The number-average molecular weight increased linearly with with monomer conversion.
Nitroxide-Mediated Free Radical Polymerization (NMP，NMRP)
Stable Free Radical Polymerization (SFRP)
基于氮氧稳定自由基的活性自由基
聚合
2020/9/18
1. NMP的发现及历史：
Georges M K, et al. (Xerox Research Center of Canada) Macromolecules, 1993,36,2987-2988
As a comparison, Georges performed a suspension copolymerization of styrene and butadiene with (a) and without (b) TEMPO. The PDI of the polymer with TEMPO was 1.36 while the PDI of the polymer without TEMPO was 4.61.
2020/9/18
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
2020/9/18
2020/9/18
1. NMP的发现及历史：
2,2,4,4-四甲基派啶氮氧稳定自由基 (2,2,4,4-tetramethyl-1-piperidinyloxy, TEMPO)
相对TD，其活性更低
H 3C
CH 3
，不能引发聚合，且与
H 3C
N
CH 3
苯乙烯增长链末端结合 的键更弱。
O
自由基捕获剂、阻聚剂、抗老化剂、热降解抑制剂和热稳定剂等。
双分子体系 BPO:TEMPO=1:1.3
Poorly defined nature of the initiating
species
2020/9/18
单分子体系(Unimolecular) ：
2020/9/18
单分子体系可控效果 优于双分子体系！
2020/9/18
2. NMP的聚合机理
• Typically these propagating carbon centered radicals are transient species , tend to disappear by self-termination, which is typically a diffusion controlled process. This raises the question, why do we only see minor amounts of irreversible termination in NMP?
2020/9/18
2020/9/18
J. Am. Chem. SOC. 1994,116, 11185-11186
SOLOMON八十年代的工作：
用稳定自由基封端研究St、 MMA关于引发和终止的结构
2020/9/18
SOLOMON八十年代的工作：
2020/9/18
SOLOMON八十年代的工作：
202子量与转化率间线性关系！ TEMPO/BPO比例对聚合的影响！
2020/9/18
1. NMP的发现及历史：
Many subsequent studies have confirmed Georges findings and have also shown that increasing the molar ratio of nitroxide to initiator result in slower reactions, lower PDIs, and lower molecular weight polymers.
2020/9/18
1. NMP的发现及历史：
2020/9/18
Rizzardo等与TEMPO/SFRP失之交臂？温度低，分布 宽
the term living, controlled and step growth were used.
2020/9/18
N O
polystyreneCH2 CH
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
R·,Y·活泼自由基，则产物有三种, 1:2:1。 R·活泼自由基，Y·persistent radical, 产物只有一种
2020/9/18
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
N O
polystyreneCH2 CH
Polymerization Systen: Monomer: Styrene Initiator: BPO Additive: TEMPO
Conditions: Initial heating at 95oC for 3.5h, followed by heating at 123oC for 69h. Results: Narrow molecular weight polystyrene with polydispersity of 1.26. The number-average molecular weight increased linearly with with monomer conversion.
Polymerization Systen: Monomer: Styrene Initiator: BPO Additive: TEMPO
Conditions: Initial heating at 95oC for 3.5h, followed by heating at 123oC for 69h. Results: Narrow molecular weight polystyrene with polydispersity of 1.26. The number-average molecular weight increased linearly with with monomer conversion.
Nitroxide-Mediated Free Radical Polymerization (NMP，NMRP)
Stable Free Radical Polymerization (SFRP)
基于氮氧稳定自由基的活性自由基
聚合
2020/9/18
1. NMP的发现及历史：
Georges M K, et al. (Xerox Research Center of Canada) Macromolecules, 1993,36,2987-2988
As a comparison, Georges performed a suspension copolymerization of styrene and butadiene with (a) and without (b) TEMPO. The PDI of the polymer with TEMPO was 1.36 while the PDI of the polymer without TEMPO was 4.61.
2020/9/18
2. NMP的聚合机理 2.1 平衡的建立： persistent radical effect
2020/9/18
2020/9/18
1. NMP的发现及历史：
2,2,4,4-四甲基派啶氮氧稳定自由基 (2,2,4,4-tetramethyl-1-piperidinyloxy, TEMPO)
相对TD，其活性更低
H 3C
CH 3
，不能引发聚合，且与
H 3C
N
CH 3
苯乙烯增长链末端结合 的键更弱。
O
自由基捕获剂、阻聚剂、抗老化剂、热降解抑制剂和热稳定剂等。
双分子体系 BPO:TEMPO=1:1.3
Poorly defined nature of the initiating
species
2020/9/18
单分子体系(Unimolecular) ：
2020/9/18
单分子体系可控效果 优于双分子体系！
2020/9/18
2. NMP的聚合机理
• Typically these propagating carbon centered radicals are transient species , tend to disappear by self-termination, which is typically a diffusion controlled process. This raises the question, why do we only see minor amounts of irreversible termination in NMP?
2020/9/18
2020/9/18
J. Am. Chem. SOC. 1994,116, 11185-11186
SOLOMON八十年代的工作：
用稳定自由基封端研究St、 MMA关于引发和终止的结构
2020/9/18
SOLOMON八十年代的工作：
2020/9/18
SOLOMON八十年代的工作：
202子量与转化率间线性关系！ TEMPO/BPO比例对聚合的影响！
2020/9/18
1. NMP的发现及历史：
Many subsequent studies have confirmed Georges findings and have also shown that increasing the molar ratio of nitroxide to initiator result in slower reactions, lower PDIs, and lower molecular weight polymers.
2020/9/18
1. NMP的发现及历史：
2020/9/18
Rizzardo等与TEMPO/SFRP失之交臂？温度低，分布 宽
the term living, controlled and step growth were used.
2020/9/18
N O
polystyreneCH2 CH