Mechanochemical synthesis of poly(lactic acid) block copolymers: overcoming the miscibility of the macroinitiator, monomer and catalyst under solvent-free conditions

2019 ◽  
Vol 10 (4) ◽  
pp. 539-545 ◽  
Author(s):  
Gue Seon Lee ◽  
Bo Reum Moon ◽  
Haemin Jeong ◽  
Jihoon Shin ◽  
Jeung Gon Kim

Efficient mixing and energy delivery by ball-milling promoted the lactide polymer growth from macroinitiators without the use of a solvent.

2019 ◽  
Vol 15 ◽  
pp. 963-970 ◽  
Author(s):  
Sora Park ◽  
Jeung Gon Kim

Mechanochemical polymerization is a rapidly growing area and a number of polymeric materials can now be obtained through green mechanochemical synthesis. In addition to the general merits of mechanochemistry, such as being solvent-free and resulting in high conversions, we herein explore rate acceleration under ball-milling conditions while the conventional solution-state synthesis suffer from low reactivity. The solvent-free mechanochemical polymerization of trimethylene carbonate using the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) are examined herein. The polymerizations under ball-milling conditions exhibited significant rate enhancements compared to polymerizations in solution. A number of milling parameters were evaluated for the ball-milling polymerization. Temperature increases due to ball collisions and exothermic energy output did not affect the polymerization rate significantly and the initial mixing speed was important for chain-length control. Liquid-assisted grinding was applied for the synthesis of high molecular weight polymers, but it failed to protect the polymer chain from mechanical degradation.


2019 ◽  
Vol 7 (37) ◽  
pp. 11406-11410 ◽  
Author(s):  
Francisco Palazon ◽  
Yousra El Ajjouri ◽  
Paz Sebastia-Luna ◽  
Simone Lauciello ◽  
Liberato Manna ◽  
...  

Solvent-free mechanochemical synthesis of phase-pure inorganic halide perovskites is investigated in depth revealing several beneficial and detrimental effects of ball-milling.


2019 ◽  
Vol 1 (12) ◽  
pp. 3354-3365
Author(s):  
Neha Mulchandani ◽  
Arvind Gupta ◽  
Kazunari Masutani ◽  
Sachin Kumar ◽  
Shinichi Sakurai ◽  
...  

2020 ◽  
Vol 59 (31) ◽  
pp. 13956-13968
Author(s):  
Hai Jiang ◽  
Yingli Ding ◽  
Juyang Liu ◽  
Arun Alagarsamy ◽  
Li Pan ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 41 (31) ◽  
pp. no-no
Author(s):  
Geraldine Epane ◽  
Jean Claude Laguerre ◽  
Anne Wadouachi ◽  
Delphine Marek

2013 ◽  
Vol 9 ◽  
pp. 786-790 ◽  
Author(s):  
Laramie P Jameson ◽  
Sergei V Dzyuba

BODIPY dyes have been synthesized under solvent-free or essentially solvent-free conditions, within about 5 minutes in an open-to-air setup by using a pestle and mortar, with yields that are comparable to those obtained via traditional routes that typically require reaction times of several hours to days.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Wenwen Yu ◽  
Lijing Zhu ◽  
Jiangao Shi ◽  
Cunting Zhao

Poly(lactic acid)-block-poly(N,N-dimethylaminoethyl methacrylate) (PLA-PDMAEMA) copolymers were synthesized from aminolyzed PLA via reversible addition fragmentation (RAFT) polymerization. PLA undergoes aminolytic degradation with ethylenediamine (EDA). The kinetics of the aminolysis reaction of PLA at different temperatures and EDA concentrations was investigated in detail. The molar masses of products rapidly decreased in the initial stage at low aminolytic degree. Meanwhile, reactive –NH2 and –OH groups were introduced to the end of shorter PLA chains and used as sites to further immobilize the RAFT agent. PLA-PDMAEMA block copolymers were synthesized. A pseudo-first-order reaction kinetics was observed for the RAFT polymerization of PDMAEMA at a low conversion. By controlling the aminolysis reaction of PLA and RAFT polymerization degree of DMAEMA, the length distributions of the PLA and PDMAEMA blocks can be controlled. This method can be extended to more systems to obtain block copolymers with controllable block structure.


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