Pub Date : 2017-01-23DOI: 10.6000/1929-5995.2016.05.04.3
Mingsen Chen, H. Zhou, Xiaofang Li, Li Zhou, Faai Zhang
In this study, we used ethyl 2-bromopropionate (EBrP) as an initiator of activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) of methyl methacrylate (MMA). We investigated in detail the effect on polymerization of different kinds of reducing agents and ligands, the amounts of the reducing agent and catalyst, and reaction temperature. We determined the molecular weight and dispersity of the polymers by gel permeation chromatography (GPC). The results reveal glucose to be the best reducing agent for this system. The monomer conversion increased with increases in the reaction temperature and in the feeding amounts of the reducing agent and catalyst. The optimum amount of the reducing agent and minimal amount of catalyst required depend on the particular system. For example, we polymerized MMA with 200 ppm of catalyst and 15-fold of glucose/CuCl 2 resulting in a PMMA with high M n ( M n,GPC = 48 700, M n,theo = 48 500) and low dispersity (1.27). The first-order kinetics show that the molecular weights increased linearly with the monomer conversion and are consistent with the theoretical values, the chain extension reaction and end group analysis results also demonstrate that the characteristics of polymerization process belong to a typical “livingâ€/controlled radical polymerization. Moreover, 1 H-NMR analysis results indicate the stereoregularity of the polymer is given priority over syndiotactic architecture and the effect of the type of ligand on the stereoregularity is very slight.
{"title":"Optimizing Activators Regenerated by Electron Transfer for Atom Transfer Radical Polymerization of Methyl Methacrylate Initiated by Ethyl 2-bromopropionate","authors":"Mingsen Chen, H. Zhou, Xiaofang Li, Li Zhou, Faai Zhang","doi":"10.6000/1929-5995.2016.05.04.3","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.04.3","url":null,"abstract":"In this study, we used ethyl 2-bromopropionate (EBrP) as an initiator of activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) of methyl methacrylate (MMA). We investigated in detail the effect on polymerization of different kinds of reducing agents and ligands, the amounts of the reducing agent and catalyst, and reaction temperature. We determined the molecular weight and dispersity of the polymers by gel permeation chromatography (GPC). The results reveal glucose to be the best reducing agent for this system. The monomer conversion increased with increases in the reaction temperature and in the feeding amounts of the reducing agent and catalyst. The optimum amount of the reducing agent and minimal amount of catalyst required depend on the particular system. For example, we polymerized MMA with 200 ppm of catalyst and 15-fold of glucose/CuCl 2 resulting in a PMMA with high M n ( M n,GPC = 48 700, M n,theo = 48 500) and low dispersity (1.27). The first-order kinetics show that the molecular weights increased linearly with the monomer conversion and are consistent with the theoretical values, the chain extension reaction and end group analysis results also demonstrate that the characteristics of polymerization process belong to a typical “livingâ€/controlled radical polymerization. Moreover, 1 H-NMR analysis results indicate the stereoregularity of the polymer is given priority over syndiotactic architecture and the effect of the type of ligand on the stereoregularity is very slight.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"10 1","pages":"149-157"},"PeriodicalIF":0.0,"publicationDate":"2017-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87556240","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}
Pub Date : 2017-01-23DOI: 10.6000/1929-5995.2016.05.04.4
J. Assaad
The incorporation of recycled polymers from waste latex paints (WLPs) in concrete manufacturing is very limited. In fact, this practice cannot be formally implemented without thorough assessment of the various implications that could result from WLP additions on concrete properties. This paper seeks to provide better understanding on effect of WLP constituents and substitution rates on concrete fresh and mechanical properties. It also examines the effect of incorporating naphthalene-based high-range water reducer (HRWR) to mitigate the detrimental effects associated with such additions. Tested WLPs were not randomly collected from waste collection sites; rather produced to assure full traceability of composition and then stored for around 1-year to expire. Test results have shown that workability, setting time, and hardened properties of concrete are directly affected by the polymer latex type and content including the pigment/extender ratio. The use of HRWR is efficient to control work ability and its loss over time when WLPs are disposed in concrete at relatively high rate of 10% of mixing water. The incorporation of HRWR should be coupled with certain reduction in free water to control the drop in compressive strength and bond to embedded steel bars.
{"title":"Use of High- Range Water Reducer to Mitigate the Detrimental Effect of Recycled Acrylic- Based Polymers on Concrete Performance","authors":"J. Assaad","doi":"10.6000/1929-5995.2016.05.04.4","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.04.4","url":null,"abstract":"The incorporation of recycled polymers from waste latex paints (WLPs) in concrete manufacturing is very limited. In fact, this practice cannot be formally implemented without thorough assessment of the various implications that could result from WLP additions on concrete properties. This paper seeks to provide better understanding on effect of WLP constituents and substitution rates on concrete fresh and mechanical properties. It also examines the effect of incorporating naphthalene-based high-range water reducer (HRWR) to mitigate the detrimental effects associated with such additions. Tested WLPs were not randomly collected from waste collection sites; rather produced to assure full traceability of composition and then stored for around 1-year to expire. Test results have shown that workability, setting time, and hardened properties of concrete are directly affected by the polymer latex type and content including the pigment/extender ratio. The use of HRWR is efficient to control work ability and its loss over time when WLPs are disposed in concrete at relatively high rate of 10% of mixing water. The incorporation of HRWR should be coupled with certain reduction in free water to control the drop in compressive strength and bond to embedded steel bars.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"20 1","pages":"158-168"},"PeriodicalIF":0.0,"publicationDate":"2017-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87795676","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}
Pub Date : 2016-11-08DOI: 10.6000/1929-5995.2016.05.03.1
Shirin Monadjemi, C. McMahan, K. Cornish
To meet the increasing demand for natural rubber (NR), currently sourced from the tropical rubber tree Hevea brasiliensis , and address price volatility and steadily increasing labor costs, alternate rubber-producing species are in commercial development. One of these, guayule ( Parthenium argentatum ), has emerged on the market as a commercial source of high quality rubber. Non-rubber constituents play an important role in the physical properties of NR products. The intrinsic composition of the two NR materials differs and these differences may be a principal cause of the performance differences between them. We have compared the effect of non-rubber constituents, such as protein, lipids, resin and rubber particle membranes. Firstly, a film casting method was developed to obtain rubber films with a uniform thickness. Secondly, the glass transition temperature of different rubbers was determined by dynamic mechanical analysis, and tensile properties were tested for uncompounded materials. Guayule natural rubber (GNR), from which most of the membranes were removed while in latex form (MRGNR) was found to have higher intrinsic strength than GNR or gel-free NR (FNR). An acetone extraction was performed to quantify the resin and free lipids in the rubber samples.
{"title":"Effect of Non-Rubber Constituents on Guayule and Hevea Rubber Intrinsic Properties","authors":"Shirin Monadjemi, C. McMahan, K. Cornish","doi":"10.6000/1929-5995.2016.05.03.1","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.03.1","url":null,"abstract":"To meet the increasing demand for natural rubber (NR), currently sourced from the tropical rubber tree Hevea brasiliensis , and address price volatility and steadily increasing labor costs, alternate rubber-producing species are in commercial development. One of these, guayule ( Parthenium argentatum ), has emerged on the market as a commercial source of high quality rubber. Non-rubber constituents play an important role in the physical properties of NR products. The intrinsic composition of the two NR materials differs and these differences may be a principal cause of the performance differences between them. We have compared the effect of non-rubber constituents, such as protein, lipids, resin and rubber particle membranes. Firstly, a film casting method was developed to obtain rubber films with a uniform thickness. Secondly, the glass transition temperature of different rubbers was determined by dynamic mechanical analysis, and tensile properties were tested for uncompounded materials. Guayule natural rubber (GNR), from which most of the membranes were removed while in latex form (MRGNR) was found to have higher intrinsic strength than GNR or gel-free NR (FNR). An acetone extraction was performed to quantify the resin and free lipids in the rubber samples.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"49 1","pages":"87-96"},"PeriodicalIF":0.0,"publicationDate":"2016-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85252223","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}
Pub Date : 2016-11-08DOI: 10.6000/1929-5995.2016.05.03.4
J. Su, Yingyuan Wang, Shan Han, Xiao-long Zhang
Blend films from nature soy protein isolates (SPI) and synthetical poly (vinyl alcohol) (PVA) were successfully fabricated by crosslinkage of ferulic acid (FA) based on a solution-casting method. Structure analysis results indicated that FA had chemical reactions with both SPI and PVA, a three-dimensional interpenetrated polymer networks (IPN) had formed between SPI and PVA. The miscibility of SPI/PVA blends had improved by crosslinkage of FA. Moreover, the transparency of films had enhanced with the increasing of FA contents, which proved the INP structure of SPI/PVA blends could be adjusted by cross-linking degree. This method supplies a highlight potential usage of SPI as environmental-friendly packaging films.
{"title":"Soy Protein Isolate/Poly (Vinyl Alcohol) Films with IPN Structure by Crosslinkage of Ferulic Acid","authors":"J. Su, Yingyuan Wang, Shan Han, Xiao-long Zhang","doi":"10.6000/1929-5995.2016.05.03.4","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.03.4","url":null,"abstract":"Blend films from nature soy protein isolates (SPI) and synthetical poly (vinyl alcohol) (PVA) were successfully fabricated by crosslinkage of ferulic acid (FA) based on a solution-casting method. Structure analysis results indicated that FA had chemical reactions with both SPI and PVA, a three-dimensional interpenetrated polymer networks (IPN) had formed between SPI and PVA. The miscibility of SPI/PVA blends had improved by crosslinkage of FA. Moreover, the transparency of films had enhanced with the increasing of FA contents, which proved the INP structure of SPI/PVA blends could be adjusted by cross-linking degree. This method supplies a highlight potential usage of SPI as environmental-friendly packaging films.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"1 1","pages":"114-117"},"PeriodicalIF":0.0,"publicationDate":"2016-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75366203","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}
Pub Date : 2016-11-08DOI: 10.6000/1929-5995.2016.05.03.2
C. Tsao, H. Hocheng
Over the past decades, composite materials have been increasingly utilized in various industries because of their superior mechanical properties and resistance to corrosion. Drilling is essential to produce precise holes when load-carrying structures are produced using composites. Because of the non-homogeneous and anisotropic property of composite laminates, delamination often occurs at the point where the drill exits, which affects reliability and safety. Some studies present a suppressed mechanism to prevent delamination when drilling composite laminates. The experimental results demonstrate delamination is significantly reduced by various suppressed mechanisms and greater feed rates produce the same level of delamination. The use of special drill geometries and backup has been demonstrated to be more advantageous than the use of adapted feed controls. The basis for the future development of a suppression mechanism for drilling composite laminates is determined.
{"title":"A Review of Backup Mechanism for Reducing Delamination when Drilling Composite Laminates","authors":"C. Tsao, H. Hocheng","doi":"10.6000/1929-5995.2016.05.03.2","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.03.2","url":null,"abstract":"Over the past decades, composite materials have been increasingly utilized in various industries because of their superior mechanical properties and resistance to corrosion. Drilling is essential to produce precise holes when load-carrying structures are produced using composites. Because of the non-homogeneous and anisotropic property of composite laminates, delamination often occurs at the point where the drill exits, which affects reliability and safety. Some studies present a suppressed mechanism to prevent delamination when drilling composite laminates. The experimental results demonstrate delamination is significantly reduced by various suppressed mechanisms and greater feed rates produce the same level of delamination. The use of special drill geometries and backup has been demonstrated to be more advantageous than the use of adapted feed controls. The basis for the future development of a suppression mechanism for drilling composite laminates is determined.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"64 1","pages":"97-107"},"PeriodicalIF":0.0,"publicationDate":"2016-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84902220","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}
Pub Date : 2016-08-22DOI: 10.6000/1929-5995.2016.05.02.2
A. Peixoto, I. Campos, H. Ferraz, J. C. Pinto
Miniemulsion polymerization is widely used to produce polymer nanoparticles. In many applications, it is important to ensure the narrow particle size distribution of the final product, which means that secondary micellar and homogeneous nucleation must be avoided during the reaction course. The present study proposes the use of hydrophilic comonomers to inhibit the occurrence of secondary particle nucleation in miniemulsion polymerizations of methyl methacrylate. Acrylic acid, metacrylic acid, 2-hydroxy ethyl methacrylate and methacrylamide were used as hydrophilic comonomers. It was observed that the use of small amounts of hydrophilic comonomers in miniemulsion polymerizations promoted by oil-soluble initiators could prevent secondary particle nucleation and lead to products with more homogeneous particle size distributions.
{"title":"Use of Hydrophilic Monomers to Avoid Secondary Particle Nucleation in Miniemulsion Polymerizations of Methyl Methacrylate","authors":"A. Peixoto, I. Campos, H. Ferraz, J. C. Pinto","doi":"10.6000/1929-5995.2016.05.02.2","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.02.2","url":null,"abstract":"Miniemulsion polymerization is widely used to produce polymer nanoparticles. In many applications, it is important to ensure the narrow particle size distribution of the final product, which means that secondary micellar and homogeneous nucleation must be avoided during the reaction course. The present study proposes the use of hydrophilic comonomers to inhibit the occurrence of secondary particle nucleation in miniemulsion polymerizations of methyl methacrylate. Acrylic acid, metacrylic acid, 2-hydroxy ethyl methacrylate and methacrylamide were used as hydrophilic comonomers. It was observed that the use of small amounts of hydrophilic comonomers in miniemulsion polymerizations promoted by oil-soluble initiators could prevent secondary particle nucleation and lead to products with more homogeneous particle size distributions.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"48 1","pages":"60-71"},"PeriodicalIF":0.0,"publicationDate":"2016-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81024003","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}
Pub Date : 2016-08-22DOI: 10.6000/1929-5995.2016.05.02.4
N. Bel’nikevich, E. Rosova, I. Malakhova, V. Krasikov, Z. Zoolshoev, E. Popova, N. Saprykina, Galina Galina Elyashevich
Molecular characteristics of chitosan in diluted water solutions of acetic and hydrochloric acids were studied by viscometry, dynamic light scattering, and thin layer chromatography. Chitosan molecules were found to undergo destruction in the solutions of hydrochloric acid and its mixtures with acetic acid. The structure of the chitosan films cast from these solvents was studied by DSC, TGA, and SEM. As shown by electron microscopic data, all the films had an amorphous-crystalline structure but the films prepared from chitosan solutions in diluted hydrochloric acid were characterized by a higher degree of crystallinity. It was supposed that a lower molecular mass of chitosan molecules in the hydrochloric acid solutions results in more extended conformations providing a higher capability of self-organization and formation of regular supermolecular structure. The difference in crystal modification in structure of the films cast of these acids was observed. It was found that the films prepared from the mixtures of acids had a spherulite structure and the crystal modification like ones cast from hydrochloric acid, but with a lower degree of crystallinity.
{"title":"Molecular Characteristics of Chitosan and Structure of its Films Formed from Water Solutions of Acetic and Hydrochloric Acids","authors":"N. Bel’nikevich, E. Rosova, I. Malakhova, V. Krasikov, Z. Zoolshoev, E. Popova, N. Saprykina, Galina Galina Elyashevich","doi":"10.6000/1929-5995.2016.05.02.4","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.02.4","url":null,"abstract":"Molecular characteristics of chitosan in diluted water solutions of acetic and hydrochloric acids were studied by viscometry, dynamic light scattering, and thin layer chromatography. Chitosan molecules were found to undergo destruction in the solutions of hydrochloric acid and its mixtures with acetic acid. The structure of the chitosan films cast from these solvents was studied by DSC, TGA, and SEM. As shown by electron microscopic data, all the films had an amorphous-crystalline structure but the films prepared from chitosan solutions in diluted hydrochloric acid were characterized by a higher degree of crystallinity. It was supposed that a lower molecular mass of chitosan molecules in the hydrochloric acid solutions results in more extended conformations providing a higher capability of self-organization and formation of regular supermolecular structure. The difference in crystal modification in structure of the films cast of these acids was observed. It was found that the films prepared from the mixtures of acids had a spherulite structure and the crystal modification like ones cast from hydrochloric acid, but with a lower degree of crystallinity.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"22 1","pages":"80-86"},"PeriodicalIF":0.0,"publicationDate":"2016-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74968585","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}
Pub Date : 2016-04-18DOI: 10.6000/1929-5995.2016.05.01.3
Thuong H. Nguyen, M. Hasib, Dan Wang, Sam S. Sun
A novel c-D-nc-B-cf-A (or DBfA ) type of block copolymer has been designed, synthesized, characterized, and preliminarily studied for optoectronic applications, where c-D is a conjugated donor type polyphenylenevinylene (PPV) block, nc-B is a non-conjugated bridge unit, and cf-A is a conjugated and fluorinated acceptor type PPV block. The frontier HOMO/LUMO orbital levels of D and fA conjugated blocks are -5.22/-3.06 and -6.10/-3.43 as determined from electrochemical and optical measurements. Photoluminescence emissions of D and fA are quenched in DBfA indicating a potential photo induced charge separation pathway between the donor and the acceptor blocks. Solid state thin film studies revealed more uniform and nano-scale phase separated morphologies in DBfA as compared to D/fA blend. A two orders of magnitude enhancement of photoelectric energy conversion efficiency was observed in a best solar cell fabricated from the DBfA block copolymer as compared to a best cell fabricated from the corresponding D/fA blend. Such significant photoelectric conversion enhancement could be attributed to the improvements of phase separated and bicontinously ordered nanostructure (BONS) morphology in DBfA as compared to D/fA .
{"title":"Design, Synthesis, Characterizations, and Processing of a Novel c-Donor-nc-Bridge-cf-Acceptor Type Block Copolymer for Optoelecronic Applications","authors":"Thuong H. Nguyen, M. Hasib, Dan Wang, Sam S. Sun","doi":"10.6000/1929-5995.2016.05.01.3","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.01.3","url":null,"abstract":"A novel c-D-nc-B-cf-A (or DBfA ) type of block copolymer has been designed, synthesized, characterized, and preliminarily studied for optoectronic applications, where c-D is a conjugated donor type polyphenylenevinylene (PPV) block, nc-B is a non-conjugated bridge unit, and cf-A is a conjugated and fluorinated acceptor type PPV block. The frontier HOMO/LUMO orbital levels of D and fA conjugated blocks are -5.22/-3.06 and -6.10/-3.43 as determined from electrochemical and optical measurements. Photoluminescence emissions of D and fA are quenched in DBfA indicating a potential photo induced charge separation pathway between the donor and the acceptor blocks. Solid state thin film studies revealed more uniform and nano-scale phase separated morphologies in DBfA as compared to D/fA blend. A two orders of magnitude enhancement of photoelectric energy conversion efficiency was observed in a best solar cell fabricated from the DBfA block copolymer as compared to a best cell fabricated from the corresponding D/fA blend. Such significant photoelectric conversion enhancement could be attributed to the improvements of phase separated and bicontinously ordered nanostructure (BONS) morphology in DBfA as compared to D/fA .","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"26 1","pages":"18-38"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74038244","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}
Pub Date : 2016-04-18DOI: 10.6000/1929-5995.2016.05.01.1
Cong Li, Xiaoxia Cai, Chifei Wu, Guozhang Wu
Due to the strong hydrogen bonding interactions, hindered phenol 3,9-bis[1,1-dimethyl-2{ I² -(3-tert-butyl-4-hydroxy-5- methylphenyl)propionyloxy}ethyl]- 2,4,8,10-tetraoxaspiro[5,5]-undecane (AO-80) demonstrated a remarkable damping effect when it was hybridized with acrylic rubber (ACM). The loss factor of ACM could be largely increased and the position of loss peak could be regulated by controlling the content of the hindered phenol. This kind of high damping hybrids can be used as the laminated layer of sandwich beam for vibration control. Instead of the traditional method ASTM E756-98, a new method based on dynamic mechanical analyzer (DMA) was developed to characterize the damping behaviors of ACM/AO-80 laminated beam. Testing results demonstrated that DMA can reflect the variation of damping behaviors of sandwich beams with various factors effectively, and a theoretical model established here was used to explain the damping behaviors. Based on this model, by means of adjusting the content of AO-80, a high damping ability for the sandwich beam could be obtained at appointed temperature during a wide frequency range.
{"title":"ACM/Hindered Phenol Hybrids: A High Damping Material with Constrained-Layer Structure for Dynamic Mechanical Analysis and Simulation","authors":"Cong Li, Xiaoxia Cai, Chifei Wu, Guozhang Wu","doi":"10.6000/1929-5995.2016.05.01.1","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.01.1","url":null,"abstract":"Due to the strong hydrogen bonding interactions, hindered phenol 3,9-bis[1,1-dimethyl-2{ I² -(3-tert-butyl-4-hydroxy-5- methylphenyl)propionyloxy}ethyl]- 2,4,8,10-tetraoxaspiro[5,5]-undecane (AO-80) demonstrated a remarkable damping effect when it was hybridized with acrylic rubber (ACM). The loss factor of ACM could be largely increased and the position of loss peak could be regulated by controlling the content of the hindered phenol. This kind of high damping hybrids can be used as the laminated layer of sandwich beam for vibration control. Instead of the traditional method ASTM E756-98, a new method based on dynamic mechanical analyzer (DMA) was developed to characterize the damping behaviors of ACM/AO-80 laminated beam. Testing results demonstrated that DMA can reflect the variation of damping behaviors of sandwich beams with various factors effectively, and a theoretical model established here was used to explain the damping behaviors. Based on this model, by means of adjusting the content of AO-80, a high damping ability for the sandwich beam could be obtained at appointed temperature during a wide frequency range.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"14 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77939966","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}
Pub Date : 2016-04-18DOI: 10.6000/1929-5995.2016.05.01.2
D. Abulyazied, N. Mansour, A. M. Mazrouaa, M. Mohamed
In this paper, samples of Polyacrylamide (PAAm) nanosilica nanocomposites were prepared having different concentration of nanosilica (0.125, 0.25, and 0.5). Polyacrylamide (PAAm) and poly (vinyl alcohol) (PVA) were blended with different ratio (3/1, 1/1, 1/3) using solution-cast technique. The prepared films were characterized by Fourier transform infrared (FTIR), X-ray diffractions (XRD) and scanning electron microscopy (SEM). FTIR spectra showed the presence of hydrogen bonding between–CONH 2 groups in PAAm and –OH group in PVA and confirm the hydrophilic nature of the blends. X-ray diffractions shows the presence of a strong broad peak centered at 22o (2θ) confirms the amorphous nature of silica which is supposed to be the characteristic of SiO 2 . The results obtained from different experimental techniques were supported by SEM image analysis. The thermal stability of the nanocomposites enhanced by increasing the silica content in the blend. The DC electrical conductivity was studied for all prepared samples. It was found that the conductivity increase by increasing silica content as well as, increased by increasing the wt% of PVA.
{"title":"Physical Properties of Polyacrylamide/Polyvinylalcohol Silica Nanocomposites","authors":"D. Abulyazied, N. Mansour, A. M. Mazrouaa, M. Mohamed","doi":"10.6000/1929-5995.2016.05.01.2","DOIUrl":"https://doi.org/10.6000/1929-5995.2016.05.01.2","url":null,"abstract":"In this paper, samples of Polyacrylamide (PAAm) nanosilica nanocomposites were prepared having different concentration of nanosilica (0.125, 0.25, and 0.5). Polyacrylamide (PAAm) and poly (vinyl alcohol) (PVA) were blended with different ratio (3/1, 1/1, 1/3) using solution-cast technique. The prepared films were characterized by Fourier transform infrared (FTIR), X-ray diffractions (XRD) and scanning electron microscopy (SEM). FTIR spectra showed the presence of hydrogen bonding between–CONH 2 groups in PAAm and –OH group in PVA and confirm the hydrophilic nature of the blends. X-ray diffractions shows the presence of a strong broad peak centered at 22o (2θ) confirms the amorphous nature of silica which is supposed to be the characteristic of SiO 2 . The results obtained from different experimental techniques were supported by SEM image analysis. The thermal stability of the nanocomposites enhanced by increasing the silica content in the blend. The DC electrical conductivity was studied for all prepared samples. It was found that the conductivity increase by increasing silica content as well as, increased by increasing the wt% of PVA.","PeriodicalId":16998,"journal":{"name":"Journal of Research Updates in Polymer Science","volume":"15 1","pages":"10-17"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84689760","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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