scholarly journals Co-Ni Cyanide Bi-Metal Catalysts: Copolymerization of Carbon Dioxide with Propylene Oxide and Chain Transfer Agents

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 632
Author(s):  
Kirill Alferov ◽  
Shuanjin Wang ◽  
Tianhao Li ◽  
Min Xiao ◽  
Shanyue Guan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Propylene Oxide ◽  
Chain Transfer ◽  
Research Direction ◽  
Complexing Agents ◽  
Oh Groups ◽  
High Productivity ◽  
Nmr Methods ◽  
Carbon Dioxide Co2 ◽  
Transfer Agents

Synthesis of copolymers from carbon dioxide (CO2) and epoxides is an important research direction as such processes utilize the abundant greenhouse gas and deliver useful products. Specifically, cooligomers of CO2 and propylene oxide (PO) with a non-alternating structure can be used for polyurethane preparation. They are synthesized by employing Zn-Co cyanide catalysts. The application of alternative metal cyanide complexes is interesting from scientific and practical points of view. The purpose of this work was to study the copolymerization of CO2 and PO in the presence of Co-Ni cyanide catalysts and chain transfer agents (CTAs) in order to obtain low molecular weight products. Three Co-Ni catalysts with different contents of complexing agents were synthesized, characterized by several analytical methods and applied for this reaction. The complex without complexing agents was chosen for detailed investigation. 1,6-Hexanediol proved to be a more preferred CTA than poly(propylene glycol) and adipic acid. An oligo(ethercarbonate) (Mn = 2560, PDI = 2.5, CO2 = 20 mol.%) capped with OH groups was synthesized with relatively high productivity (1320 gPO+CO2/gcat in 24 h) and characterized by matrix-assisted laser desorption/ionization (MALDI) MS and NMR methods. The main chain transfer routes during the cooligomerization were suggested on the basis of the research results.

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>

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>

PERANCANGAN PROTEKSI KEBAKARAN OTOMATIS PADA KAPAL BERBASIS ARDUINO

2018 ◽  
Vol 1 (2) ◽  
pp. 1-8
Author(s):  
Dody Hidayat
Keyword(s):  
Carbon Dioxide ◽  
Fire Extinguisher ◽  
Carbon Dioxide Co2

Kebakaran dapat terjadi dimana saja salah satunya dapat terjadi di alat transportasi air yakni kapal. Kebakaran selalu menyebabkan hal-hal yang tidak diinginkan baik kerugian material maupun ancaman keselamatan jiwa manusia. Seiring dari kejadian tersebut musibah kecelakaan kapal yang disebabkan oleh bahaya kebakaran sangatlah mungkin terjadi. Salah satu yang dapat mencegah kejadian kebakaran pada kapal haruslah dapat mendeteksi dini kebakaran tersebut. Untuk mendeteksi dini terjadinya kebakaran dikapal maka dirancanglah sebuah alat proteksi kebakaran otomatisberbasis adruino. Dimana Arduino merupakan board yang memiliki sebuah mikrokontroller sebagai  otak kendali sistem. Sistem otomatisasi atau controller tidak akan terlepas dengan apa yang disebut  dengan ‘sensor’. Sensor adalah sebuah alat untuk mendeteksi atau mengukut sesuatu yang digunakan untuk mengubah variasi mekanis, magnetis, panas, sinar dan kimia menjadi tegangan dan arus listrik. sistem yang dirancang ini dilengkapi dengan beberapa sensor diantaranya adalah sensor apiUV-Tron R2868, sensor asap MQ-2 dan kemudian sensor suhuDS18B20. Mikrokontroller sebagai pengendali akan merespon input yang berupa sensor tersebut ketika data yang dibaca oleh sensor mendeteksikebakaran diantaranya mendeteksi adanya asap, kemudian api dan suhu. Sebagai output dari sistem berupa racun api (fire extinguisher)dimana kandungan yang ada pada racun api tersebut berupa Dry Chemical Powder dan Carbon Dioxide (CO2) yang fungsinya digunakan untuk memadamkan api serta dilengkapi buzzer sebagai alarm peringatan jika terjadi kebakaran. 

The Prenatal Development Effects of Carbon Dioxide (CO2) Exposure in Rats (Rattus Norvegicus)

2012 ◽  
Author(s):  
William R. Howard ◽  
Brian Wong ◽  
Michelle Okolica ◽  
Kimberly S. Bynum ◽  
R. A. James
Keyword(s):  
Carbon Dioxide ◽  
Rattus Norvegicus ◽  
Prenatal Development ◽  
Carbon Dioxide Co2
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