Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)”
博士 === 國立中興大學 === 土木工程學系所 === 96 === The reaction of aromatic carbodiimides and carboxylic acids produced aryl N-acylureas in high yields under mild conditions. Thermolysis of N-acylureas at greater than 140 ℃ gave amides and isocyanates readily, the latter could undergo the repetitive reaction sequ...
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ndltd-TW-096NCHU50150752016-05-09T04:13:47Z http://ndltd.ncl.edu.tw/handle/69405284221494033436 Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” 利用連續自我反覆反應(SSRR)合成聚醯胺-醯亞胺以及聚醯亞胺並應用於“窄分子量分布聚醯胺”之發展 Kuan-Liang Wei 魏寬良 博士 國立中興大學 土木工程學系所 96 The reaction of aromatic carbodiimides and carboxylic acids produced aryl N-acylureas in high yields under mild conditions. Thermolysis of N-acylureas at greater than 140 ℃ gave amides and isocyanates readily, the latter could undergo the repetitive reaction sequences in the presence of carbodiimide catalyst. Based on this unique pattern, the sequential self-repetitive reactions (SSRR) is developed in a versatile manner for converting aryl isocyanates into amides, amide-imide and imide. Furthermore, the SSRR reaction has also been successfully applied into poly(amide-imide) and polyimide synthesis. In addition, one-pot synthesis of poly(amide-imide) and polyimide was demonstrated have excellent thermal properties demonstrated by their TGA and DSC measurements. We have developed a novel poly-condensation for the synthesis of well-defined polyamides by the SSRR reaction. The new polymerization mechanism involved a three-step sequence of carboxylic acid addition to carbodiimide, fragmentation of N-acylurea into amide and isocyanate and isocyanate condense to carbodiimide. The new polymerization technique was demonstrated by using a hindered carbodiimide, N,N’-bis(2,6-diisopropylphenyl)carbodiimide (iPr-CDI) as an initiator, followed by slow but simultaneous addition of diacids and diisocyanates monomers to ultimately generate a polyamide with precisely controlled molecular-weight distributions. Significantly different from the conventional step-growth and chain-growth types, the formation of polymer backbone is through the monomer addition to the requisite initiator, and followed by a rearrangement to amide and fragmented component for SSRR. The mechanism of monomer addition, fragmentation and SSRR condensation in a sequential order is unique with respect to the way of forming polyamide backbone. Furthermore, the precise control of molecular weight is mainly attributed to the relative rate of sequential acid-addition and CDI-formation. At the end of each reaction cycle, a “hindered CDI” was created at the terminal of the growing amide-chain setting up for the next sequence. This new SSRR method allows the synthesis of precisely controlled polyamides that can not be obtained from the conventional poly-condensation. 戴憲弘 學位論文 ; thesis 97 en_US |
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博士 === 國立中興大學 === 土木工程學系所 === 96 === The reaction of aromatic carbodiimides and carboxylic acids produced aryl N-acylureas in high yields under mild conditions. Thermolysis of N-acylureas at greater than 140 ℃ gave amides and isocyanates readily, the latter could undergo the repetitive reaction sequences in the presence of carbodiimide catalyst. Based on this unique pattern, the sequential self-repetitive reactions (SSRR) is developed in a versatile manner for converting aryl isocyanates into amides, amide-imide and imide. Furthermore, the SSRR reaction has also been successfully applied into poly(amide-imide) and polyimide synthesis. In addition, one-pot synthesis of poly(amide-imide) and polyimide was demonstrated have excellent thermal properties demonstrated by their TGA and DSC measurements.
We have developed a novel poly-condensation for the synthesis of well-defined polyamides by the SSRR reaction. The new polymerization mechanism involved a three-step sequence of carboxylic acid addition to carbodiimide, fragmentation of N-acylurea into amide and isocyanate and isocyanate condense to carbodiimide. The new polymerization technique was demonstrated by using a hindered carbodiimide, N,N’-bis(2,6-diisopropylphenyl)carbodiimide (iPr-CDI) as an initiator, followed by slow but simultaneous addition of diacids and diisocyanates monomers to ultimately generate a polyamide with precisely controlled molecular-weight distributions. Significantly different from the conventional step-growth and chain-growth types, the formation of polymer backbone is through the monomer addition to the requisite initiator, and followed by a rearrangement to amide and fragmented component for SSRR.
The mechanism of monomer addition, fragmentation and SSRR condensation in a sequential order is unique with respect to the way of forming polyamide backbone. Furthermore, the precise control of molecular weight is mainly attributed to the relative rate of sequential acid-addition and CDI-formation. At the end of each reaction cycle, a “hindered CDI” was created at the terminal of the growing amide-chain setting up for the next sequence. This new SSRR method allows the synthesis of precisely controlled polyamides that can not be obtained from the conventional poly-condensation.
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author2 |
戴憲弘 |
author_facet |
戴憲弘 Kuan-Liang Wei 魏寬良 |
author |
Kuan-Liang Wei 魏寬良 |
spellingShingle |
Kuan-Liang Wei 魏寬良 Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
author_sort |
Kuan-Liang Wei |
title |
Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
title_short |
Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
title_full |
Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
title_fullStr |
Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
title_full_unstemmed |
Sequential Self-Repetitive Reaction (SSRR) in Synthesis of Poly (amide-imide), Polyimide and Its Subsequent Application in Development of “Well-Defined Poly(amide)” |
title_sort |
sequential self-repetitive reaction (ssrr) in synthesis of poly (amide-imide), polyimide and its subsequent application in development of “well-defined poly(amide)” |
url |
http://ndltd.ncl.edu.tw/handle/69405284221494033436 |
work_keys_str_mv |
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