{"title":"Thermal and Physical Properties of Polyurethanes Crosslinked by Polyrotaxanes—Influence of Polyrotaxane structures and Isocyanate Index—","authors":"Juae Lim, Yoshimi Tanaka, H. Murakami","doi":"10.2324/ejsm.13.1","DOIUrl":"https://doi.org/10.2324/ejsm.13.1","url":null,"abstract":"","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"25 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82692980","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}
M. Furuya, N. Shimono, K. Yamazaki, Ryota Domura, M. Okamoto
To broaden the knowledge of cytotoxicity of natural rubber latex (NRL) nanoparticles we for the first time examined the latex biocompatibility in vitro against mouse calvaria preosteoblastic cells (MC3T3-E1) and human alveolar basal epithelial (A549) cells. For NRL nanoparticles, the half maximal inhibitory concentration (IC50) value for MC3T3-E1 cells is one order of magnitude higher in toxicity as compared to that of A549 cells (3.99 mg/mL for MC3T3-E1 and 0.33 mg/mL for A549 cells). Owing to fractionation of NRL nanoparticles by ultra-centrifuge, the effect of the non-rubber constituents on the cytotoxicity was clarified. The suppression on the proliferation for A549 cells incubated with NRL nanoparticles was demonstrated by the cell cycle distribution. The in vitro study on osteogenic differentiation and expressions of proteins and characteristic genes of MC3T3-E1 cells demonstrated the promising results of the NRL nanoparticles for application in bone tissue engineering.
{"title":"Evaluation on Cytotoxicity of Natural Rubber Latex Nanoparticles and Application in Bone Tissue Engineering","authors":"M. Furuya, N. Shimono, K. Yamazaki, Ryota Domura, M. Okamoto","doi":"10.2324/EJSM.12.1","DOIUrl":"https://doi.org/10.2324/EJSM.12.1","url":null,"abstract":"To broaden the knowledge of cytotoxicity of natural rubber latex (NRL) nanoparticles we for the first time examined the latex biocompatibility in vitro against mouse calvaria preosteoblastic cells (MC3T3-E1) and human alveolar basal epithelial (A549) cells. For NRL nanoparticles, the half maximal inhibitory concentration (IC50) value for MC3T3-E1 cells is one order of magnitude higher in toxicity as compared to that of A549 cells (3.99 mg/mL for MC3T3-E1 and 0.33 mg/mL for A549 cells). Owing to fractionation of NRL nanoparticles by ultra-centrifuge, the effect of the non-rubber constituents on the cytotoxicity was clarified. The suppression on the proliferation for A549 cells incubated with NRL nanoparticles was demonstrated by the cell cycle distribution. The in vitro study on osteogenic differentiation and expressions of proteins and characteristic genes of MC3T3-E1 cells demonstrated the promising results of the NRL nanoparticles for application in bone tissue engineering.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"5 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90442036","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}
Shogo Mamada, Naoyuki Yaguchi, M. Hansaka, M. Yamato, H. Yoshida
A piezoelectric ceramic/rubber composite comprising linearly aligned Lead Zirconate Titanate (PZT) particles as pillars in a silicon rubber matrix was fabricated. The optimum fabrication conditions of pseudo 1–3 composites (referred to as ‵‵aligned-type" composites) were evaluated as the functions of the electric field strength and the piezoelectric particle size. The piezoelectric strain constant d33, which represents the value of the electric charge per unit force generated from a piezoelectric material, and the ratio of the number of particles involved in the alignments (RPIA) to all particles in an RPIA sample were used to quantitatively evaluate the composites. The d33 exhibited linear dependence on the piezoelectric particle size and a non-linear dependence on the RPIA. The RPIA depended on both the electric field strength and particle size. The electric field strength dependency of the RPIA exhibited a maximum at approximately 2 kV/mm. The optimum condition for the fabrication of the aligned-type piezoelectric rubber composite was achieved an electric field strength of 2.0 kV/mm with larger PZT particles.
{"title":"Particle Alignment Condition and Size Influence on the d 33 of the Pseudo-1-3 Piezoelectric Ceramic/Rubber Composite","authors":"Shogo Mamada, Naoyuki Yaguchi, M. Hansaka, M. Yamato, H. Yoshida","doi":"10.2324/EJSM.11.1","DOIUrl":"https://doi.org/10.2324/EJSM.11.1","url":null,"abstract":"A piezoelectric ceramic/rubber composite comprising linearly aligned Lead Zirconate Titanate (PZT) particles as pillars in a silicon rubber matrix was fabricated. The optimum fabrication conditions of pseudo 1–3 composites (referred to as ‵‵aligned-type\" composites) were evaluated as the functions of the electric field strength and the piezoelectric particle size. The piezoelectric strain constant d33, which represents the value of the electric charge per unit force generated from a piezoelectric material, and the ratio of the number of particles involved in the alignments (RPIA) to all particles in an RPIA sample were used to quantitatively evaluate the composites. The d33 exhibited linear dependence on the piezoelectric particle size and a non-linear dependence on the RPIA. The RPIA depended on both the electric field strength and particle size. The electric field strength dependency of the RPIA exhibited a maximum at approximately 2 kV/mm. The optimum condition for the fabrication of the aligned-type piezoelectric rubber composite was achieved an electric field strength of 2.0 kV/mm with larger PZT particles.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"12 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73473025","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}
Four polyurethanes (PUs) crosslinked by polyrotaxanes (PRXs) of two filling ratios of CyD (63% for PRX4000 and 37% for PRX6000) and with modification ratios of 1 and 2 for a PU chain. The PUs were abbreviated as PU6000(1) , PU6000(2) , PU4000(1) , and PU4000(2) , in which 4000 and 6000 are the molecular weights of PEGs as an axle molecule of the PRX and the numbers in parentheses are the modification ratios of the PU chain. ATR-FT-IR, DSC, viscoelastic measurements and tensile test were carried out to investigate their thermal and physical properties. The formation of hydrogen bonds between the PU chains increased with increase in the modification ratio of the PU chain. PU4000(2) possessing the half filling ratio of CyD and higher modification ratio of the PU chain made the recrystal lization of the soft segment slow. PU4000(1) with the half filling ratio of CyD and lower modification ratio of the PU chain showed the highest tensile strength among the PUs. In contrast, PU6000(2) with the lower filling ratio of CyD and higher modification ratio of the PU chain showed the highest elongation among the PUs, implying that the sliding effect based on the rotaxane structure occurred.
{"title":"Synthesis and Characterization of Polyurethanes Crosslinked by Polyrotaxanes of Two Filling Ratios of α-Cyclodextrin and with Two Modification Ratios of Polyurethane Chain","authors":"H. Murakami, T. Kondo, Rei Baba, Natsumi Nonaka","doi":"10.2324/EJSM.10.9","DOIUrl":"https://doi.org/10.2324/EJSM.10.9","url":null,"abstract":"Four polyurethanes (PUs) crosslinked by polyrotaxanes (PRXs) of two filling ratios of CyD (63% for PRX4000 and 37% for PRX6000) and with modification ratios of 1 and 2 for a PU chain. The PUs were abbreviated as PU6000(1) , PU6000(2) , PU4000(1) , and PU4000(2) , in which 4000 and 6000 are the molecular weights of PEGs as an axle molecule of the PRX and the numbers in parentheses are the modification ratios of the PU chain. ATR-FT-IR, DSC, viscoelastic measurements and tensile test were carried out to investigate their thermal and physical properties. The formation of hydrogen bonds between the PU chains increased with increase in the modification ratio of the PU chain. PU4000(2) possessing the half filling ratio of CyD and higher modification ratio of the PU chain made the recrystal lization of the soft segment slow. PU4000(1) with the half filling ratio of CyD and lower modification ratio of the PU chain showed the highest tensile strength among the PUs. In contrast, PU6000(2) with the lower filling ratio of CyD and higher modification ratio of the PU chain showed the highest elongation among the PUs, implying that the sliding effect based on the rotaxane structure occurred.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"89 1","pages":"9-15"},"PeriodicalIF":0.0,"publicationDate":"2014-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79392081","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}
Carbon dioxide (CO2) laser supersonic drawing is a new technique for preparation of nanofibers in a vacuum chamber using a CO2 laser and a supersonic air jet formed directly below the fiber supply orifice. In this study, we have applied a CO2 laser supersonic multi-drawing method to nylon 66 to produce nanofiber sheets. A fiber of 182 μm in diameter was drawn at a drawing speed of 223 m s-1 and a draw ratio of approximately 1.3×105 to obtain a nanofiber sheet having 25 cm length, 17 cm width, 61.5 μm thickness, and an average nanofiber diameter of approximately 0.5 μm. The nanofiber sheet exhibited two melting temperature (Tm), 259°C (Tm1) and 270°C (Tm2). Tm2 is approximately 10°C higher than the Tm value of nylon 66 at usual. The sheet showed no drastic fiber shrinkage during heating, and the fiber form was held even at the temperature of the usual melting temperature or higher.
二氧化碳激光超声速拉伸是一种在真空室中制备纳米纤维的新技术，利用CO2激光器和在光纤供应孔下方形成的超音速气流在真空室中制备纳米纤维。在本研究中，我们将CO2激光超音速多次拉伸法应用于尼龙66生产纳米纤维片材。以223 m s-1的拉伸速度和约1.3×105的拉伸比拉伸出直径为182 μm的纳米纤维，得到长25 cm、宽17 cm、厚61.5 μm、平均纳米纤维直径约0.5 μm的纳米纤维片。纳米纤维片的熔化温度为259°C (Tm1)和270°C (Tm2)。Tm2比通常尼龙66的Tm值高约10℃。在加热过程中，纤维没有剧烈收缩，即使在通常的熔化温度或更高的温度下，纤维形态也保持不变。
{"title":"Nylon 66 Nanofiber Sheets Prepared by Carbon Dioxide Laser Supersonic Multi-drawing","authors":"T. Hasegawa, Takumi Mikuni, A. Suzuki","doi":"10.2324/EJSM.10.1","DOIUrl":"https://doi.org/10.2324/EJSM.10.1","url":null,"abstract":"Carbon dioxide (CO2) laser supersonic drawing is a new technique for preparation of nanofibers in a vacuum chamber using a CO2 laser and a supersonic air jet formed directly below the fiber supply orifice. In this study, we have applied a CO2 laser supersonic multi-drawing method to nylon 66 to produce nanofiber sheets. A fiber of 182 μm in diameter was drawn at a drawing speed of 223 m s-1 and a draw ratio of approximately 1.3×105 to obtain a nanofiber sheet having 25 cm length, 17 cm width, 61.5 μm thickness, and an average nanofiber diameter of approximately 0.5 μm. The nanofiber sheet exhibited two melting temperature (Tm), 259°C (Tm1) and 270°C (Tm2). Tm2 is approximately 10°C higher than the Tm value of nylon 66 at usual. The sheet showed no drastic fiber shrinkage during heating, and the fiber form was held even at the temperature of the usual melting temperature or higher.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"68 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2014-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80232393","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}
To create novel antistatic polymer materials, we prepared ion-conductive elastomer blends consisting of commercial NBR (with acrylonitrile (AN) content of 18 and 33% (NBR18, NBR33)) with nano-ordered domains of polyether electrolyte. In this study, we prepared blend samples using two different methods, solvent-casting and mechanical mixing methods. The oligo-[(ethylene oxide)-co-(propylene oxide)] methacrylate (M(EO/PO)) was mixed and polymerized in the NBR matrix including KSCN. Obtained elastomer blends showed relatively good conductivity more than 10−7 S cm−1 and the difference in the conductivity of the cast samples under dry and wet conditions was especially very small, and the ratio of conductivity under dry and wet condition of NBR18 blends was lower than 0.06. The TEM images indicated that the order of sea-island phase separation in blend samples may effect on the ion-conductive behavior under different humidity conditions. Moreover, the NBR33 with 30 wt% of PM(EO/PO) sample showed the conductivity of the order of 10−6 S cm−1, and we considered that the large interface between NBR33 and polyether electrolyte domains may effect the increase in the conductivity.
为了创造新的抗静电高分子材料，我们制备了由商用丁腈橡胶(丙烯腈含量分别为18%和33% (NBR18, NBR33))和聚醚电解质的纳米有序畴组成的离子导电弹性体共混物。在本研究中，我们采用溶剂铸造和机械混合两种不同的方法制备了混合样品。将低聚[(环氧乙烷)-co-(环氧丙烷)]甲基丙烯酸酯(M(EO/PO))混合在含KSCN的丁腈橡胶基体中进行聚合。所得弹性体共混物的电导率均在10−7 S cm−1以上，且铸态样品在干湿条件下的电导率差异非常小，其中NBR18共混物的干湿条件电导率比小于0.06。TEM图像表明，在不同湿度条件下，混合样品的海岛相分离顺序对离子导电性能有影响。此外，添加30 wt% PM(EO/PO)的NBR33样品的电导率为10−6 S cm−1，我们认为NBR33与聚醚电解质畴之间的大界面可能影响了电导率的提高。
{"title":"Nano-Ordered Sea-Island Phase Separation of Ion-Conductive Elastomer Blends Based on NBR and Polyether Electrolytes","authors":"Y. Kubota, Y. Tominaga","doi":"10.2324/EJSM.9.9","DOIUrl":"https://doi.org/10.2324/EJSM.9.9","url":null,"abstract":"To create novel antistatic polymer materials, we prepared ion-conductive elastomer blends consisting of commercial NBR (with acrylonitrile (AN) content of 18 and 33% (NBR18, NBR33)) with nano-ordered domains of polyether electrolyte. In this study, we prepared blend samples using two different methods, solvent-casting and mechanical mixing methods. The oligo-[(ethylene oxide)-co-(propylene oxide)] methacrylate (M(EO/PO)) was mixed and polymerized in the NBR matrix including KSCN. Obtained elastomer blends showed relatively good conductivity more than 10−7 S cm−1 and the difference in the conductivity of the cast samples under dry and wet conditions was especially very small, and the ratio of conductivity under dry and wet condition of NBR18 blends was lower than 0.06. The TEM images indicated that the order of sea-island phase separation in blend samples may effect on the ion-conductive behavior under different humidity conditions. Moreover, the NBR33 with 30 wt% of PM(EO/PO) sample showed the conductivity of the order of 10−6 S cm−1, and we considered that the large interface between NBR33 and polyether electrolyte domains may effect the increase in the conductivity.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"2007 1","pages":"9-13"},"PeriodicalIF":0.0,"publicationDate":"2013-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82579067","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. Takenaka, Daiki Nakashima, M. Miya, Hiroki Takeshita, T. Shiomi
(cid:633) Anionic polymerization of two 1,3-butadiene derivatives containing trimethylsilyl-protected primary amino groups, 2-( N , N -bistrimethylsilylaminomethyl)-1,3-butadiene ( SA1Bd ) and 2-(4-( N , N -bistrimethylsilylamino)butyl)-1,3-butadiene ( SA4Bd ) were carried out under various conditions. When anionic polymerization of SA1Bd was attempted in cyclohexane at room temperature with using sec -BuLi as an initiator, no polymerization took place at all. Polystyrene having dienyl end group was obtained if anionic living polystyrene was used as an initiator, presumably due to the isomerization of carbanion accompanied with elimination of bistrimethylsilylamide anion. Such a side reaction was not observed in the anionic polymerization of SA4Bd . Polymer of predictable molecular weight with narrow molecular weight distributions was obtained in the polymerization in toluene. Microstructure of the resulting polymer was 86% 1,4-struc-ture though its geometry was not clear. Block copolymer with styrene was also obtained.
(cid:633)在不同条件下阴离子聚合了2-(N, N -双strimethylsilylaminomethyl)-1,3-butadiene (SA1Bd)和2-(4-(N, N -双strimethylsilylamino)butyl)-1,3-butadiene (SA4Bd)两个含有三甲基硅基保护的一级氨基的1,3-丁二烯衍生物。在环己烷中以二苯胺为引发剂，在室温下进行SA1Bd阴离子聚合，没有发生聚合。以阴离子型活性聚苯乙烯为引发剂，可以得到端基为二烯基的聚苯乙烯，这可能是由于碳离子的异构化与双三甲基硅酰胺阴离子的消去有关。在SA4Bd的阴离子聚合中未观察到这种副反应。在甲苯中聚合得到了分子量可预测且分子量分布窄的聚合物。所得聚合物的微观结构86%为1,4结构，但其几何结构不清楚。还得到了苯乙烯嵌段共聚物。
{"title":"Anionic polymerization of 2-(N,N-bistrimethylsilylaminomethyl)-1,3-butadiene and 2-(4-(N,N-bistrimethylsilylamino)butyl)-1,3-butadiene","authors":"K. Takenaka, Daiki Nakashima, M. Miya, Hiroki Takeshita, T. Shiomi","doi":"10.2324/EJSM.9.14","DOIUrl":"https://doi.org/10.2324/EJSM.9.14","url":null,"abstract":"(cid:633) Anionic polymerization of two 1,3-butadiene derivatives containing trimethylsilyl-protected primary amino groups, 2-( N , N -bistrimethylsilylaminomethyl)-1,3-butadiene ( SA1Bd ) and 2-(4-( N , N -bistrimethylsilylamino)butyl)-1,3-butadiene ( SA4Bd ) were carried out under various conditions. When anionic polymerization of SA1Bd was attempted in cyclohexane at room temperature with using sec -BuLi as an initiator, no polymerization took place at all. Polystyrene having dienyl end group was obtained if anionic living polystyrene was used as an initiator, presumably due to the isomerization of carbanion accompanied with elimination of bistrimethylsilylamide anion. Such a side reaction was not observed in the anionic polymerization of SA4Bd . Polymer of predictable molecular weight with narrow molecular weight distributions was obtained in the polymerization in toluene. Microstructure of the resulting polymer was 86% 1,4-struc-ture though its geometry was not clear. Block copolymer with styrene was also obtained.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"186 1","pages":"14-19"},"PeriodicalIF":0.0,"publicationDate":"2013-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72710346","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. Takenaka, Mayumi Arimoto, Hiroki Takeshita, M. Miya, T. Shiomi
Free-radical polymerization of tetraethyl (2,3-dimethylenebutane-1,4-diyl)bis(phosphonate), a 1,3-butadi-ene derivative containing two diethyl phosphonate functions in a molecule, was carried out under various conditions. When polymerization was performed in benzene at 60 ° C for 21 h with using 1 mol% of 2,2 ′ -azobisisobutyronitrile as an initiator, sticky polymer was obtained in 70% yield without forming gel. Number average molecular weight of the polymer thus obtained was estimated to be 69,000 by SEC based on polystyrene calibration using N , N -dimethylformamide as an eluent. The rate of polymerization was found to be proportional to 0.5 and 1.5 power of the initiator and the monomer concentration, respectively. The overall activation energy of polymerization was determined to be 91.4 kJ/mol. The microstructure of the polymer was exclusively 1,4- but both E and Z configurations were contained. Glass transition temperature of the polymer was − 18 ° C. Monomer reactivity ratio of the monomer with styrene as comonomer was determined to be r st =0.15,
在不同的条件下，自由基聚合了含有两个膦酸二乙酯功能的1,3-丁二烯衍生物四乙基(2,3-二亚甲基丁烷-1,4-二基)二膦酸盐。在苯中，以1 mol%的2,2′-偶氮二异丁腈为引发剂，在60℃下聚合21 h，得到了产率为70%的粘性聚合物，未形成凝胶。基于聚苯乙烯校准，以N, N -二甲基甲酰胺作为洗脱剂，由此获得的聚合物的数平均分子量通过SEC估计为69,000。聚合速率分别与引发剂的0.5和1.5次方成正比，与单体浓度成正比。聚合反应的总活化能为91.4 kJ/mol。聚合物的微观结构完全为1,4-，但同时包含E和Z两种构型。该聚合物的玻璃化转变温度为- 18℃，单体与苯乙烯为共聚物的反应性比为r st =0.15;
{"title":"Free-radical polymerization of tetraethyl (2,3-dimethylenebutane-1,4-diyl)bis(phosphonate)","authors":"K. Takenaka, Mayumi Arimoto, Hiroki Takeshita, M. Miya, T. Shiomi","doi":"10.2324/EJSM.9.1","DOIUrl":"https://doi.org/10.2324/EJSM.9.1","url":null,"abstract":"Free-radical polymerization of tetraethyl (2,3-dimethylenebutane-1,4-diyl)bis(phosphonate), a 1,3-butadi-ene derivative containing two diethyl phosphonate functions in a molecule, was carried out under various conditions. When polymerization was performed in benzene at 60 ° C for 21 h with using 1 mol% of 2,2 ′ -azobisisobutyronitrile as an initiator, sticky polymer was obtained in 70% yield without forming gel. Number average molecular weight of the polymer thus obtained was estimated to be 69,000 by SEC based on polystyrene calibration using N , N -dimethylformamide as an eluent. The rate of polymerization was found to be proportional to 0.5 and 1.5 power of the initiator and the monomer concentration, respectively. The overall activation energy of polymerization was determined to be 91.4 kJ/mol. The microstructure of the polymer was exclusively 1,4- but both E and Z configurations were contained. Glass transition temperature of the polymer was − 18 ° C. Monomer reactivity ratio of the monomer with styrene as comonomer was determined to be r st =0.15,","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"99 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2013-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75224492","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}
This is the second paper of a series that describes the curing process of styrene-butadiene-rubber packed in a cylindrical mold with inner diameter of 74.6 mm. Present paper mainly describes the curing process under the mold cooling stage. Sulfur was used as the curing agent and the sulfur concentration ranged from 1.0 to 5.0 weight percent. The mold temperature was controlled in two stages. The mold was heated at 414 K for 45 min. then switched off, and the mold was cooled by natural convection to the surroundings up to 75 min. Time-dependent radial distributions of the temperature profile and the crosslink density were measured in the cooling stage. It was confirmed that the curing reaction was related strongly to the temperature field. In the cooling stage, rubber temperature decreased in the outer zone whereas overshooted in the inner zone. The degree of cure at the rubber center reached to around 0.8 at time 45–60 min. elapsed after taking the heater off for sulfur concentration of 1 and 3 weight percent.
{"title":"Experimental Study on the Curing Process of Styrene-Butadiene-Rubber","authors":"H. Tsuji, S. Nozu, H. Miura, Kenji Onishi","doi":"10.2324/EJSM.8.1","DOIUrl":"https://doi.org/10.2324/EJSM.8.1","url":null,"abstract":"This is the second paper of a series that describes the curing process of styrene-butadiene-rubber packed in a cylindrical mold with inner diameter of 74.6 mm. Present paper mainly describes the curing process under the mold cooling stage. Sulfur was used as the curing agent and the sulfur concentration ranged from 1.0 to 5.0 weight percent. The mold temperature was controlled in two stages. The mold was heated at 414 K for 45 min. then switched off, and the mold was cooled by natural convection to the surroundings up to 75 min. Time-dependent radial distributions of the temperature profile and the crosslink density were measured in the cooling stage. It was confirmed that the curing reaction was related strongly to the temperature field. In the cooling stage, rubber temperature decreased in the outer zone whereas overshooted in the inner zone. The degree of cure at the rubber center reached to around 0.8 at time 45–60 min. elapsed after taking the heater off for sulfur concentration of 1 and 3 weight percent.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"24 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2012-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73858123","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}
Change and restoration in carbon black filler network in SBR through reversing double-step large shear deformations were studied by the use of differential dynamic modulus. Unfilled rubber showed drop and complete recovery in G′ after elimination of step shear strain γ=0.5, showing drop in G′ is not due to chain scission but due to filler network rupture. Filled rubber also shows similar change and recovery in G′, but rises over the initial value at long time region. This long time behavior may be due to physical aging. Elimination of the effect of physical aging allowed us to estimate relaxation time in restoration process. It was concluded that (a) differential dynamic modulus measured in recovery process is useful for the characterization of filler network, (b) carbon black filler network ruptured by strain recovers to the original structure by particle diffusion process, and (c) recovery rate of carbon black filler network is independent of amount of filler loading and deformation history.
{"title":"Filler Network Recovery of Carbon Black Filled Rubber","authors":"Yoshinobu Isono, Taiki Terasaki","doi":"10.2324/EJSM.8.9","DOIUrl":"https://doi.org/10.2324/EJSM.8.9","url":null,"abstract":"Change and restoration in carbon black filler network in SBR through reversing double-step large shear deformations were studied by the use of differential dynamic modulus. Unfilled rubber showed drop and complete recovery in G′ after elimination of step shear strain γ=0.5, showing drop in G′ is not due to chain scission but due to filler network rupture. Filled rubber also shows similar change and recovery in G′, but rises over the initial value at long time region. This long time behavior may be due to physical aging. Elimination of the effect of physical aging allowed us to estimate relaxation time in restoration process. It was concluded that (a) differential dynamic modulus measured in recovery process is useful for the characterization of filler network, (b) carbon black filler network ruptured by strain recovers to the original structure by particle diffusion process, and (c) recovery rate of carbon black filler network is independent of amount of filler loading and deformation history.","PeriodicalId":11628,"journal":{"name":"E-journal of Soft Materials","volume":"8 1","pages":"9-14"},"PeriodicalIF":0.0,"publicationDate":"2012-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88402717","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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