Synthesis of biodegradable polycarbonate by alternating copolymerization of carbon dioxide and propylene oxide using a cobalt/Schiff base catalyst

2011 ◽  
Vol 71 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Hongchun Li ◽  
Yongsheng Niu
Keyword(s):  
Carbon Dioxide ◽  
Schiff Base ◽  
Propylene Oxide ◽  
Base Catalyst ◽  
Alternating Copolymerization

Alternating Copolymerization of Carbon Dioxide and Propylene Oxide Catalyzed by Cobalt Schiff Base Complex

2009 ◽  
Vol 210 (15) ◽  
pp. 1224-1229 ◽  
Author(s):  
Yongsheng Niu ◽  
Hongchun Li ◽  
Xuesi Chen ◽  
Wanxi Zhang ◽  
Xiuli Zhuang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Schiff Base ◽  
Propylene Oxide ◽  
Schiff Base Complex ◽  
Base Complex ◽  
Alternating Copolymerization

Chiral salenCo(iii) complexes with bulky substituents as catalysts for stereoselective alternating copolymerization of racemic propylene oxide with carbon dioxide and succinic anhydride

2021 ◽  
Vol 12 (12) ◽  
pp. 1776-1786
Author(s):  
Zhou Wang ◽  
Ying Mu
Keyword(s):  
Carbon Dioxide ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Succinic Anhydride ◽  
Poly Propylene ◽  
Alternating Copolymerization

Stereoregular poly(propylene carbonate)s and poly(propylene succinate-block-carbonate)s were synthesized with new chiral salenCo(iii) catalysts carrying bulky substituents.

scholarly journals Tertiary Amines Paired with Trialkyl Boranes: A Simple Organocatalyst for Fully Alternating Copolymerization of Carbon Dioxide and Propylene Oxide

2020 ◽  
Author(s):  
Xing-Hong Zhang
Keyword(s):  
Carbon Dioxide ◽  
Small Molecules ◽  
Propylene Oxide ◽  
Average Molecular Weight ◽  
Tertiary Amines ◽  
Carbon Dioxide Co2 ◽  
Poly Propylene ◽  
Alternating Copolymerization ◽  
Completely Alternating ◽  
Huge Challenge

Metal-free synthesis of fully alternating polycarbonates from carbon dioxide (CO2) and epoxides is highly desired but a huge challenge. Here, we disclose the combination of tertiary amines with trialkyl boranes for completely alternating copolymerization of CO2 with epoxides. Triethylamine (TEA) pairing with triethyl borane (TEB), the simplest catalyst for the copolymerization of CO2 and propylene oxide (PO), afforded fully alternating poly(propylene carbonate) (PPC) with a turnover frequency (TOF) of 54 h-1 at 60 oC. Remarkably, diamine such as, N,N,N',N'-tetraethylethylenediamine (TEED) and triamine such as N,N,N',N'',N''-pentamethyldiethylene triamine (PMDETA) pairing with TEB exhibited improved the copolymer selectivity of up to 99%. Supplementally, the effect of trialkylborane structure on the copolymerization were also investigated. Moreover, PPCs prepared from these tertiary amines/ trialkyl boranes Lewis pairs showed the head-to-tail diad content of around 80%. The number-average molecular weight of PPC was up to 56.0 kg/mol with narrow distribution (Đ =1.16) and could be easily adjusted by simply varying the feeding ratios. The 1H NMR spectra and MALDI-TOF-MS spectra suggest that both tertiary amine-activating CO2 and TEB-masked end anions cooperatively promote the fully alternating CO2/epoxide copolymerization. This work provides an organocatalytic platform for well-defined CO2/epoxide copolymers using simple small molecules with high atomic utilization.<br>

scholarly journals Tertiary Amines Paired with Trialkyl Boranes: A Simple Organocatalyst for Fully Alternating Copolymerization of Carbon Dioxide and Propylene Oxide

2020 ◽  
Author(s):  
Xing-Hong Zhang ◽  
Ying Wang ◽  
Haoke Zhang ◽  
Jiraya Kiriratnikom ◽  
Xiao-Han Cao ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Small Molecules ◽  
Propylene Oxide ◽  
Average Molecular Weight ◽  
Tertiary Amines ◽  
Carbon Dioxide Co2 ◽  
Poly Propylene ◽  
Alternating Copolymerization ◽  
Completely Alternating ◽  
Huge Challenge

Metal-free synthesis of fully alternating polycarbonates from carbon dioxide (CO2) and epoxides is highly desired but a huge challenge. Here, we disclose the combination of tertiary amines with trialkyl boranes for completely alternating copolymerization of CO2 with epoxides. Triethylamine (TEA) pairing with triethyl borane (TEB), the simplest catalyst for the copolymerization of CO2 and propylene oxide (PO), afforded fully alternating poly(propylene carbonate) (PPC) with a turnover frequency (TOF) of 54 h-1 at 60 oC. Remarkably, diamine such as, N,N,N',N'-tetraethylethylenediamine (TEED) and triamine such as N,N,N',N'',N''-pentamethyldiethylene triamine (PMDETA) pairing with TEB exhibited improved the copolymer selectivity of up to 99%. Supplementally, the effect of trialkylborane structure on the copolymerization were also investigated. Moreover, PPCs prepared from these tertiary amines/ trialkyl boranes Lewis pairs showed the head-to-tail diad content of around 80%. The number-average molecular weight of PPC was up to 56.0 kg/mol with narrow distribution (Đ =1.16) and could be easily adjusted by simply varying the feeding ratios. The 1H NMR spectra and MALDI-TOF-MS spectra suggest that both tertiary amine-activating CO2 and TEB-masked end anions cooperatively promote the fully alternating CO2/epoxide copolymerization. This work provides an organocatalytic platform for well-defined CO2/epoxide copolymers using simple small molecules with high atomic utilization.<br>

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