Reversible addition-fragmentation chain transfer free radical polymerization method

An addition-fragmentation and chain-transfer technology, applied in the field of reversible addition-fragmentation chain transfer radical polymerization, can solve the problems of rate retardation, long reaction time, and decrease in polymerization reaction rate, and achieve increased polymerization rate and small molecular weight distribution index. , the effect of convenient control

Inactive Publication Date: 2007-02-21
SUZHOU UNIV
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Problems solved by technology

However, many researchers have found the phenomenon of rate retardation in the process of RAFT research, that is, the polymerization rate of some RAFT polymerization systems is significantly lower than the polymerization rate without chain transfer agent (RAFT agent), and the increase of chain The concentration of transfer agent will further reduce the polymerization rate
Therefore, compared with the usual free radical polymerization, the polymerization using the RAFT polymerization system requires a longer reaction time

Method used

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  • Reversible addition-fragmentation chain transfer free radical polymerization method
  • Reversible addition-fragmentation chain transfer free radical polymerization method
  • Reversible addition-fragmentation chain transfer free radical polymerization method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Embodiment one: see attached figure 1 to attach image 3 As shown, the polymerization of styrene was carried out by microwave radiation treatment with reversible addition-fragmentation chain transfer radical polymerization.

[0028] A. Use CPDN as RAFT reagent and AIBN as initiator.

[0029] Monomer styrene (Styrene, St, Shanghai Reagent Company) was washed with alkali to colorless, then washed with deionized water until neutral, dried with anhydrous magnesium sulfate, and then used by distillation under reduced pressure. AIBN (Shanghai Reagent Company) was recrystallized twice with ethanol and then dried under vacuum at room temperature for use. Chain transfer agent (RAFT reagent) CPDN was synthesized according to literature method (Zhu J.; Zhu X.L.; Cheng Z.P.; Lu J.M., Liu F., Polymer, 2002, 43, 7037-7042). The rest of the reagents were all products from Shanghai Reagent Factory, and were used after being processed by the usual method.

[0030] The styrene RAFT p...

Embodiment 2

[0076] Example 2: Reversible addition-fragmentation chain transfer radical polymerization of methyl methacrylate under microwave irradiation.

[0077] A. Use CPDN as RAFT reagent and AIBN as initiator

[0078] Monomer methyl methacrylate (Shanghai Reagent Company) was purified by vacuum distillation after alkali washing, water washing and drying. Initiator AIBN is refined by ethanol recrystallization. RAFT reagent CPDN was synthesized according to literature.

[0079] Microwave radiation polymerization: prepare the polymerization reaction solution with methyl methacrylate, CPDN, ​​and AIBN at a ratio of 500:2:1 and place it in the polymerization reaction tube, vacuum degassing-nitrogen flushing, repeat three times, and then seal the tube under nitrogen atmosphere . Add 300ml of n-hexane (the normal boiling point is 69°C, the actual measured value under the experimental conditions is 72°C) into a 500mL two-neck bottle, irradiate with 450W power until the solvent refluxes, pu...

Embodiment 3

[0124] Example 3: Reversible addition-fragmentation chain transfer radical polymerization of methyl acrylate under microwave irradiation.

[0125] Monomer methyl acrylate (Shanghai Reagent Company) was purified by vacuum distillation after alkali washing, water washing and drying. Initiator AIBN is refined by ethanol recrystallization. RAFT reagent CPDN was synthesized according to literature.

[0126] Microwave radiation polymerization: Methyl acrylate, CPDN, ​​AIBN prepared a polymerization reaction solution in a ratio of 500:2:1, placed in a polymerization reaction tube, vacuum degassing-nitrogen flushing, repeated three times, and then sealed the tube under nitrogen atmosphere. Add 300ml of n-hexane (the normal boiling point is 69°C, the actual measured value under the experimental conditions is 72°C) into a 500mL two-neck bottle, irradiate with 450W power until the solvent refluxes, put it into the reaction tube, and set the time and power (450W), continuous irradiation...

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Abstract

The invention discloses a reversible addition-fragmentation chain transfer free radical polymerization method, wherein characterized in that, microwave radiation heating can be used for polymerization, and it is possible not to use initiating agent . The invention can greatly increase polymerization speed, andconveniently control molecular weight of polymerization product.

Description

technical field [0001] The invention relates to a method for free radical polymerization, in particular to a method for reversible addition fragmentation chain transfer free radical polymerization. Background technique [0002] Living radical polymerization, because of its mild polymerization conditions, can effectively control the molecular weight and molecular weight distribution of the polymerized product, and can be used to synthesize polymers with specific structures such as block, graft and hyperbranched, has become a new trend in polymer chemistry in recent years. A hot spot of research. Reversible addition-fragmentation chain transfer radical polymerization (RAFT) is a kind of living radical polymerization, which has attracted people's attention because of its good molecular weight and molecular weight distribution control performance. However, many researchers have found the phenomenon of rate retardation in the process of RAFT research, t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F12/08C08F4/04C08F2/38C08F2/56
Inventor 朱秀林朱健程振平
Owner SUZHOU UNIV
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