Here, we investigated the thermal oxidation process of a phenolic antioxidant in polyethylene ( PE ) by using FT - IR imaging. The peaks of the phenolic group of the antioxidant change by being oxidized with a higher sensitivity than the carbonyl group peak in the FT - IR spectra. Thus it became possible to visualize the oxidation process of PE in more detail. Samples of PE containing a phenolic antioxidant were being kept in air at 60 ° C for up to 11300 hours, and the following results were obtained. ( i ) The antioxidant inside PE was not oxidized. ( ii ) The antioxidant di ff used from the inside of PE to the surface, where it was oxidized. ( iii ) The oxidation started at the surface of PE and the speed of oxidation inside PE was very high because of the low concentration of the antioxidant.
{"title":"Visualization of the Thermal Oxidation of Polyethylene Containing Phenolic Antioxidant","authors":"Kiyomi Okada","doi":"10.1295/KORON.2018-0063","DOIUrl":"https://doi.org/10.1295/KORON.2018-0063","url":null,"abstract":"Here, we investigated the thermal oxidation process of a phenolic antioxidant in polyethylene ( PE ) by using FT - IR imaging. The peaks of the phenolic group of the antioxidant change by being oxidized with a higher sensitivity than the carbonyl group peak in the FT - IR spectra. Thus it became possible to visualize the oxidation process of PE in more detail. Samples of PE containing a phenolic antioxidant were being kept in air at 60 ° C for up to 11300 hours, and the following results were obtained. ( i ) The antioxidant inside PE was not oxidized. ( ii ) The antioxidant di ff used from the inside of PE to the surface, where it was oxidized. ( iii ) The oxidation started at the surface of PE and the speed of oxidation inside PE was very high because of the low concentration of the antioxidant.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86708690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Niwa, Takafumi Yamamoto, T. Hashimoto, Michio Urushisaki, T. Sakaguchi
synthesis of star - shaped cyclopolymers. Living cationic cyclopolymerization of 1,2 - bis ( 2 - vinyloxyethoxy )- 3,5 - di - tert - butylbenzene ( 1 ) was investigated with the CH 3 CH ( O i Bu )-OCOCH 3 / Et 1.5 AlCl 1.5 / CH 3 COOEt initiating system in toluene at 0 ° C. All the reactions proceeded quantitatively to give gel - free polymers, soluble in organic solvents. The number - average molecular weight ( M n ) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that living cyclopolymerization of 1 occurred. The content of unreacted vinyl groups in the produced soluble polymers was less than ³ 2mol%, and therefore, the degree of cyclization of the polymers was determined to be over ³ 98%. Preparation of high - molecular - weight cyclopoly ( 1 ) was achieved by sequential monomer addition to the living polymerization system and polymer linking reaction of living cyclopoly ( 1 ) leading to star - shaped polymers. Glass transition temperature ( T g ) of linear cyclopoly ( 1 ) ( M n = 18,500 ) was 134 ° C and T g of star - shaped cyclopoly ( 1 ) ( M n = 95,900 ) was 132 ° C, and thermal decomposition temperatures ( T d s ) of these cyclopoly ( 1 ) were over 350 ° C, indicating their high thermal stability.
星形环状聚合物的合成。以ch3ch (O i Bu)- ococh3 / Et 1.5 alcl1.5 / ch3cooet为引发体系，在0℃甲苯中，研究了1,2 -二(2 -乙烯氧基乙氧基)- 3,5 -二叔丁基苯(1)的阳离子活性环聚合反应。聚合物的数-平均分子量(mn)与单体转化率成正比增加，在几乎完全聚合的反应混合物中加入新鲜的单体进料后，聚合物的数-平均分子量(mn)进一步增加，表明发生了活性环聚合。制备的可溶聚合物中未反应的乙烯基含量小于³2mol%，因此确定了聚合物的环化度大于³98%。通过在活性聚合体系中序次单体加成和活性环聚(1)的聚合物连接反应，制备了高分子量环聚(1)。线性环聚(1)(mn = 18,500)的玻璃化转变温度(T g)为134℃，星形环聚(1)(M n = 95,900)的T g为132℃，热分解温度(T d s)均在350℃以上，表明它们具有较高的热稳定性。
{"title":"Living Cationic Cyclopolymerization of Divinyl Ether with Bulky Substituents: Synthesis of High-Molecular-Weight Cyclopolymers and Star-Shaped Cyclopolymers","authors":"T. Niwa, Takafumi Yamamoto, T. Hashimoto, Michio Urushisaki, T. Sakaguchi","doi":"10.1295/KORON.2019-0002","DOIUrl":"https://doi.org/10.1295/KORON.2019-0002","url":null,"abstract":"synthesis of star - shaped cyclopolymers. Living cationic cyclopolymerization of 1,2 - bis ( 2 - vinyloxyethoxy )- 3,5 - di - tert - butylbenzene ( 1 ) was investigated with the CH 3 CH ( O i Bu )-OCOCH 3 / Et 1.5 AlCl 1.5 / CH 3 COOEt initiating system in toluene at 0 ° C. All the reactions proceeded quantitatively to give gel - free polymers, soluble in organic solvents. The number - average molecular weight ( M n ) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that living cyclopolymerization of 1 occurred. The content of unreacted vinyl groups in the produced soluble polymers was less than ³ 2mol%, and therefore, the degree of cyclization of the polymers was determined to be over ³ 98%. Preparation of high - molecular - weight cyclopoly ( 1 ) was achieved by sequential monomer addition to the living polymerization system and polymer linking reaction of living cyclopoly ( 1 ) leading to star - shaped polymers. Glass transition temperature ( T g ) of linear cyclopoly ( 1 ) ( M n = 18,500 ) was 134 ° C and T g of star - shaped cyclopoly ( 1 ) ( M n = 95,900 ) was 132 ° C, and thermal decomposition temperatures ( T d s ) of these cyclopoly ( 1 ) were over 350 ° C, indicating their high thermal stability.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90519029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shun Oura, Takumi Watanabe, Haruka Minato, D. Suzuki
In order to realize drug delivery systems, deeper understanding of the relationship between the position of colloidal particles, fl owing in a microchannel, and particle characteristics, such as size and softness, is crucial. However, the in fl uence of the softness of the particles on the fl owing position ( or segregation ) in colloidal mixtures containing polymeric microspheres is still not clear. In this study, we investigated the particle position of binary mixtures in microchannels, observed by an optical microscope equipped with a high - speed camera, and clari fi ed the e ff ect of microgel softness on the segregation. These fi ndings help designing carrier microspheres, for some applications, including drug delivery systems and as arti fi cial blood cells.
{"title":"Impact of Particle Softness on Segregation of Binary Colloidal Suspensions Flowing in a Microchannel","authors":"Shun Oura, Takumi Watanabe, Haruka Minato, D. Suzuki","doi":"10.1295/KORON.2019-0003","DOIUrl":"https://doi.org/10.1295/KORON.2019-0003","url":null,"abstract":"In order to realize drug delivery systems, deeper understanding of the relationship between the position of colloidal particles, fl owing in a microchannel, and particle characteristics, such as size and softness, is crucial. However, the in fl uence of the softness of the particles on the fl owing position ( or segregation ) in colloidal mixtures containing polymeric microspheres is still not clear. In this study, we investigated the particle position of binary mixtures in microchannels, observed by an optical microscope equipped with a high - speed camera, and clari fi ed the e ff ect of microgel softness on the segregation. These fi ndings help designing carrier microspheres, for some applications, including drug delivery systems and as arti fi cial blood cells.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75441854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuki Togawa, Shin-ichi Yamamoto, S. Hayashi, T. Koizumi
[Notes] Here, we demonstrate that the direct arylation polycondensation of fl uoroarenes with dibromoarenes proceeds e ffi ciently under the conditions that we have previously reported for the synthesis of other polymers. The polycondensation of 1.2.4.5 - tetra fl uorobenzene, 1,2,3,5 - tetra fl uorobenzene or 2,2 B ,3,3 B ,5,5 B ,6,6 B - octa fl uorobiphenyl with 5,5 B - dibromo - 3,3 B - dihexyl - 2,2 B - bitiophene, 3,6 - dibromo - N - octylcarbazole or 4,4 B - dibromo - N -( 2 - ethyl hexyl ) diphenylamine in the presence of palladium acetate ( 2.5mol% ) , di - tert - butylmethylphosphonium tetra fl uoroborate ( 5.0mol% ) , acetic acid ( 2eq. ) , and potassium carbonate ( 6eq. ) in toluene ( 0.5mL ) at 120 ° C for 24h gave the corresponding alternating polymers.
[注释]在这里，我们证明了在我们之前报道的合成其他聚合物的条件下，氟芳烃与二溴芳烃的直接芳基化缩聚可以有效地进行。1.2.4.5的缩聚,利乐fl uorobenzene, 1, 2, 3, 5 - tetra fl uorobenzene或2,2 B, 3, 3, 5, 5, 6, 6 B -八面体fl uorobiphenyl 5、5 B - dibromo 3 3 B -十二烷- 2,2 B - bitiophene, 3、6 - dibromo - N - octylcarbazole或4,4 B - dibromo - N -(2 -乙基己基)二苯胺的醋酸钯(2.5摩尔%),di -叔- butylmethylphosphonium利乐fl uoroborate(5.0摩尔%),乙酸(2)式。、碳酸钾(6eq.)在甲苯(0.5mL)中，在120℃下24h得到相应的交替聚合物。
{"title":"Direct Arylation Polycondensation of Fluoroarenes with Dibromoarenes","authors":"Yuki Togawa, Shin-ichi Yamamoto, S. Hayashi, T. Koizumi","doi":"10.1295/KORON.2019-0005","DOIUrl":"https://doi.org/10.1295/KORON.2019-0005","url":null,"abstract":"[Notes] Here, we demonstrate that the direct arylation polycondensation of fl uoroarenes with dibromoarenes proceeds e ffi ciently under the conditions that we have previously reported for the synthesis of other polymers. The polycondensation of 1.2.4.5 - tetra fl uorobenzene, 1,2,3,5 - tetra fl uorobenzene or 2,2 B ,3,3 B ,5,5 B ,6,6 B - octa fl uorobiphenyl with 5,5 B - dibromo - 3,3 B - dihexyl - 2,2 B - bitiophene, 3,6 - dibromo - N - octylcarbazole or 4,4 B - dibromo - N -( 2 - ethyl hexyl ) diphenylamine in the presence of palladium acetate ( 2.5mol% ) , di - tert - butylmethylphosphonium tetra fl uoroborate ( 5.0mol% ) , acetic acid ( 2eq. ) , and potassium carbonate ( 6eq. ) in toluene ( 0.5mL ) at 120 ° C for 24h gave the corresponding alternating polymers.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75249054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Kikuchi, Hirano Katsuhiko, Kouichi Kurosawa, M. Kawakami, H. Furukawa
{"title":"Influence on Particle Double-Network Gels by Gamma Irradiation and Improvement of Radiation Tolerance","authors":"K. Kikuchi, Hirano Katsuhiko, Kouichi Kurosawa, M. Kawakami, H. Furukawa","doi":"10.1295/KORON.2019-0007","DOIUrl":"https://doi.org/10.1295/KORON.2019-0007","url":null,"abstract":"","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74380111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Higuchi, Naomi Kumano, M. Harada, K. Kudo, M. Ishi, Hiroshi Nakamura
The catalyst layers in fuel cells are manufactured by drying slurries called catalyst inks. Since cracks which often appear in the catalyst layer a ff ect the performance of fuel cell, it is important to control the formation of the cracks in the manufacturing processes. Understanding the formation mechanisms of cracks helps to control the crack formation. However, the mechanisms are not su ffi ciently clari fi ed because catalyst inks are complex slurries. In this paper, we investigated the density structures during the drying processes of catalyst layers in a fuel cell by radiography observations using synchrotron X - rays at the SPring - 8 BL33XU beam line in order to clarify the crack formations. The results reveal that the cracks are generated at lower density areas than the surroundings as well as at clumps in the drying fi lm. We conclude that controlling both the density distribution during the drying process and the clumps in the catalyst ink is e ff ective for controlling the size and concentration of the cracks.
{"title":"Analysis of Crack Initiation Sites of Fuel Cell Catalyst Layers","authors":"Y. Higuchi, Naomi Kumano, M. Harada, K. Kudo, M. Ishi, Hiroshi Nakamura","doi":"10.1295/KORON.2018-0053","DOIUrl":"https://doi.org/10.1295/KORON.2018-0053","url":null,"abstract":"The catalyst layers in fuel cells are manufactured by drying slurries called catalyst inks. Since cracks which often appear in the catalyst layer a ff ect the performance of fuel cell, it is important to control the formation of the cracks in the manufacturing processes. Understanding the formation mechanisms of cracks helps to control the crack formation. However, the mechanisms are not su ffi ciently clari fi ed because catalyst inks are complex slurries. In this paper, we investigated the density structures during the drying processes of catalyst layers in a fuel cell by radiography observations using synchrotron X - rays at the SPring - 8 BL33XU beam line in order to clarify the crack formations. The results reveal that the cracks are generated at lower density areas than the surroundings as well as at clumps in the drying fi lm. We conclude that controlling both the density distribution during the drying process and the clumps in the catalyst ink is e ff ective for controlling the size and concentration of the cracks.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81179191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Halogenation of Propagating Terminal in Anionic Polymerization of Isoprene for the Synthesis of Block Copolymers","authors":"K. Satoh, Y. Mori, M. Kamigaito","doi":"10.1295/KORON.2019-0004","DOIUrl":"https://doi.org/10.1295/KORON.2019-0004","url":null,"abstract":"","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89227392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
[Notes] A urethane acrylate derived from castor oil was synthesized using castor oil with 2 - acryloyloxyethyl isocyanate and obtained in high yield. Furthermore, the obtained urethane acrylate was subjected to a UV cure reaction with polybutadiene. The UV cured fi lm was characterized by thermal and mechanical measurements. The thermal stability of the obtained fi lm was measured by TGA, and 20% thermal weight loss temperature at 425 ° C was observed. The glass transition temperature of the product was ¹ 60 ° C as revealed by DMA. The Young ’ s modulus of the product was 2.00MPa, taken from the stress - strain curve.
{"title":"Crosslinking Reaction of Polybutadiene Using Urethane Acrylate Derived from Castor Oil","authors":"N. Uchida, Kousuke Shimomura, H. Kouzai","doi":"10.1295/KORON.2016-0008","DOIUrl":"https://doi.org/10.1295/KORON.2016-0008","url":null,"abstract":"[Notes] A urethane acrylate derived from castor oil was synthesized using castor oil with 2 - acryloyloxyethyl isocyanate and obtained in high yield. Furthermore, the obtained urethane acrylate was subjected to a UV cure reaction with polybutadiene. The UV cured fi lm was characterized by thermal and mechanical measurements. The thermal stability of the obtained fi lm was measured by TGA, and 20% thermal weight loss temperature at 425 ° C was observed. The glass transition temperature of the product was ¹ 60 ° C as revealed by DMA. The Young ’ s modulus of the product was 2.00MPa, taken from the stress - strain curve.","PeriodicalId":17878,"journal":{"name":"Kobunshi Ronbunshu","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85819571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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