Iranian Polymer Journal最新文献_第9页

Direct measurement of microfibril structures in polyacrylonitrile fibers during carbon fiber manufacturing process 在碳纤维制造过程中直接测量聚丙烯腈纤维的微纤维结构

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-10 DOI: 10.1007/s13726-024-01317-6

Quan Gao, Zhihan Wang, Yongfa Zhou, Jiang Ren

{"title":"Direct measurement of microfibril structures in polyacrylonitrile fibers during carbon fiber manufacturing process","authors":"Quan Gao, Zhihan Wang, Yongfa Zhou, Jiang Ren","doi":"10.1007/s13726-024-01317-6","DOIUrl":"10.1007/s13726-024-01317-6","url":null,"abstract":"<div><p>The exceptional tensile strength and modulus of high-performance carbon fibers are determined by the microstructure evolution during the manufacturing process. The comprehension of the internal morphology of polyacrylonitrile (PAN) fibers is crucial for establishing the robust structure–property relationship and achieving superior mechanical properties in the fibers. In this work, a combination method of the ultrathin sectioning and electron microscopy technique was developed and employed for the analysis of internal structure features of the nascent fibers, precursor fibers, pre-oxidized fibers and carbon fibers. The microfibril elements were already formed during the coagulation stage and further developed within the carbon fibers through spinning, thermal stabilization and carbonization processes. Subsequently, the unoriented microfibrillar network underwent a transformation into dense fibrils, and the crystal layers within these microfibrils experienced a conversion into the turbostratic graphite structures. Based on the Nano-IR2-FS results, the morphological changes of the microfibrils were found to be intricately associated with the evolution of chemical structure, implying a strong correction between them. Through analysis of the modulus differences, it became possible to distinguish between the crystalline domains and amorphous regions, facilitating the establishment of a relationship between the mechanical strength and the microfibril structures. This work presented a direct measurement method for unraveling the complex hierarchical structures of polymer fibers, which held great potential for developing high-performance polymer fibers.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 9","pages":"1245 - 1255"},"PeriodicalIF":2.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating a hybrid approach for harvesting nanofibrillated cellulose from agricultural byproducts: sugarcane bagasse and pineapple crown leaves 研究从农副产品（甘蔗渣和菠萝冠叶）中提取纳米纤维素的混合方法

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-09 DOI: 10.1007/s13726-024-01316-7

Anusiya Ganesan, Jaiganesh Rengarajan

{"title":"Investigating a hybrid approach for harvesting nanofibrillated cellulose from agricultural byproducts: sugarcane bagasse and pineapple crown leaves","authors":"Anusiya Ganesan, Jaiganesh Rengarajan","doi":"10.1007/s13726-024-01316-7","DOIUrl":"10.1007/s13726-024-01316-7","url":null,"abstract":"<div><p>Sugarcane bagasse (SCB) and pineapple crown leaves (PCL) as low-cost waste biomass generated from the industries were subjected to chemo-mechanical modification to compare the morphology, charge, and thermal stability of native and modified biomass, accompanied by their cellulose-rich fractions. A novel aspect of this research lies in the versatility of the hybrid approach for sustainable production of cellulose polymers from an array of biomass sources. Using scanning electron microscopy (SEM), the surface morphology and structure of the samples were examined. To give thorough insights into the material characteristics, other techniques such as Fourier transform infrared spectroscopy (FTIR), zeta potential, X-ray diffraction (XRD), and thermogravimetric/differential thermal analysis (TG/DTA) were used. According to the findings, after being exposed to the hybrid treatment, the modified sample had a more ordered crystalline structure than the raw biomass (supported by the FTIR spectra), the XRD results indicated that the crystallinity index (CrI) raised with crystallite size. Although the cellulose-rich fraction extracted by the hybrid method showed better thermal stability, the overall thermal analysis revealed that biomass produced by the hybrid method had lower thermal stability than the raw biomass. The current work showed that combining ultrasonication with sulfuric acid hydrolysis is a successful hybrid method for separating cellulose nanofibers from the cellulosic plant fiber sources for reinforced composite products.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1157 - 1170"},"PeriodicalIF":2.4,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Luffa and Kevlar fiber/nanoclay sustainable thermoset biocomposites: acoustic and tribo-mechanical study 丝瓜和凯夫拉纤维/纳米粘土可持续热固性生物复合材料：声学和三力学研究

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-09 DOI: 10.1007/s13726-024-01306-9

Kumaresan Gladys Ashok, Alagesan Praveen Kumar, Munisamy Raju, Gurusamy Kasirajan

{"title":"Luffa and Kevlar fiber/nanoclay sustainable thermoset biocomposites: acoustic and tribo-mechanical study","authors":"Kumaresan Gladys Ashok, Alagesan Praveen Kumar, Munisamy Raju, Gurusamy Kasirajan","doi":"10.1007/s13726-024-01306-9","DOIUrl":"10.1007/s13726-024-01306-9","url":null,"abstract":"<div><p>Natural fiber composites often exhibit significant acoustic behavior in low-frequency range. The focus of this study is to create soundproof panels using luffa and Kevlar fiber composites reinforced using nanoclay (MMT) filler. Mechanical testing was performed on the prepared samples. The addition of 4% MMT improved the mechanical characteristics. Mechanical parameters such as interlaminar shear, tensile, flexural, and impact strength were enhanced by 9.13%, 16.89%, 9.71% and 51.64%, respectively, as compared to the control sample. Tribological experiments were performed on the manufactured composite samples in dry sliding conditions as a function of control factors such as sliding speed, sliding distance, and effective load. The results reveal that using 6% MMT to Kevlar/LCF epoxy composites greatly increases the COF and specific wear rate. The sound absorption test results indicated that the incorporation of nano MMT with Kevlar/LCF composites increased the sound transmission loss. The reduced hydrophilicity effect has been reported with the addition of 4% (by weight) MMT in contact angle measurement studies. Moreover, the created biocomposites are low-cost and long-lasting materials suitable for use as soundproofing panels in automobiles and railway cabins.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1091 - 1109"},"PeriodicalIF":2.4,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of Hydroxyl Terminated Fatty Ester Amide (DFEAm) from Dehydrated Castor Oil (DCO) and its Utilization in Various Polyurethane Coating Applications 从脱水蓖麻油 (DCO) 中合成羟基端基脂肪酸酯酰胺 (DFEAm) 及其在各种聚氨酯涂料中的应用

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-09 DOI: 10.1007/s13726-024-01310-z

Debarati Maity, Akash B. Borkar, Aarti P. More, Anagha S. Sabnis

{"title":"Synthesis of Hydroxyl Terminated Fatty Ester Amide (DFEAm) from Dehydrated Castor Oil (DCO) and its Utilization in Various Polyurethane Coating Applications","authors":"Debarati Maity, Akash B. Borkar, Aarti P. More, Anagha S. Sabnis","doi":"10.1007/s13726-024-01310-z","DOIUrl":"10.1007/s13726-024-01310-z","url":null,"abstract":"<div><p>Vegetable oils have gained popularity now-a-days as renewable resources due to their accessibility, affordability, non-toxicity and biodegradability. Globally, scientists have been making efforts to lessen dependency on feed stocks derived from petroleum-based resources. Dehydrated castor oil (DCO) being bio-based, non-edible, quick-drying compared to castor oil, imparting flexibility and excellent color retention was used as the main source of raw material in this work. Present study aims at single-step synthesis of dehydrated castor oil fatty amide (DFAm) by reacting dehydrated castor oil (DCO) with diethanolamine (DEA) avoiding the methyl ester synthesis step. The product obtained was then purified and characterized chemically and analytically. Further, DFAm was modified successfully to its hydroxyl-terminated fatty ester amide (DFEAm) derivative using sebacic acid (SA) and tris-2-hydroxyethyl isocyanurate (THEIC). THEIC, being heterocyclic in nature and imparting excellent thermal and chemical resistance, makes it suitable and novel to be used in coating applications. DFEAm was then successfully cured with various isocyanate adducts on mild steel substrates. Commercially available hydroxyl-terminated short oil alkyd was selected for comparative study under simultaneous conditions. These polyurethane coatings were evaluated as per ASTM standards for their optical, mechanical, chemical, thermal and anti-corrosive properties. DFEAm PU coatings exhibited comparable mechanical and inferior chemical properties but superior thermal and anti-corrosion properties than that of the commercial PU coatings.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 9","pages":"1203 - 1214"},"PeriodicalIF":2.4,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of non-woven antistatic substrate materials on polyvinylidene fluoride electrospun nanofibers: fabrication, characterization, and performance evaluation 无纺抗静电基底材料对聚偏氟乙烯电纺纳米纤维的影响：制造、表征和性能评估

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-09 DOI: 10.1007/s13726-024-01312-x

Venkata Dinesh Avvari, D. Kimmer, Santosh Kumar Sahu, Vasavi Boggarapu, Petr Slobodian, T. Pavan Rahul, Mahesh Gotte, P. S. Rama Sreekanth

{"title":"Influence of non-woven antistatic substrate materials on polyvinylidene fluoride electrospun nanofibers: fabrication, characterization, and performance evaluation","authors":"Venkata Dinesh Avvari, D. Kimmer, Santosh Kumar Sahu, Vasavi Boggarapu, Petr Slobodian, T. Pavan Rahul, Mahesh Gotte, P. S. Rama Sreekanth","doi":"10.1007/s13726-024-01312-x","DOIUrl":"10.1007/s13726-024-01312-x","url":null,"abstract":"<div><p>The production of nanofibers holds significant importance in both laboratory-based research and industrial applications. This study employed multiple spinnerets in the process of electrospinning to produce polyvinylidene fluoride (PVDF) nanofibers, which exhibited a desirable characteristic of being both thin and uniform. The spinning performance of multiple jet electrospinning was done. In addition, an examination was conducted to assess the impact of antistatic non-woven support materials on the fiber morphology of PVDF electrospun nanofibers. The morphology and β-phase (beta phase) of the electrospun nanofibers were analyzed using characterization techniques, such as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The findings of the study indicate that the selection of antistatic non-woven support material had a notable impact on fiber morphology. Upon the utilization of various suitable substrate materials, polyethylene terephthalate (PET) contributed to the successful formation of well-structured and consistent nanofibers with a lesser diameter of 173 ± 38 nm, 92.8% β-fraction and a surface area of 12.99 m<sup>2</sup>/g. The laminating temperature and density of the fiber decreased the porosity and air permeability by 50%. The excellent flux recovery of 400 L/(m<sup>2</sup> h) on the nanofibers laminated at 130 °C of pore size of 0.54 µm even after dried and stored for 48 h at room temperature. A finite-element analysis (FEA) was conducted on computer-aided design (CAD) fiber structure, and results showed that at low pressure of 0.01 N, a max of 130.29 MPa stress was generated on fibers.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1111 - 1127"},"PeriodicalIF":2.4,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced electromechanical actuation in acrylic elastomer foam using barium titanate and Ketjenblack dispersed interpenetrated polymer network 利用钛酸钡和 Ketjenblack 分散互穿聚合物网络增强丙烯酸弹性体泡沫中的机电致动功能

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-05 DOI: 10.1007/s13726-024-01308-7

Dhananjay Sahu, Raj Kumar Sahu

{"title":"Enhanced electromechanical actuation in acrylic elastomer foam using barium titanate and Ketjenblack dispersed interpenetrated polymer network","authors":"Dhananjay Sahu, Raj Kumar Sahu","doi":"10.1007/s13726-024-01308-7","DOIUrl":"10.1007/s13726-024-01308-7","url":null,"abstract":"<div><p>VHB 4910/05 polymeric foam tape manufactured by 3M conglomerate is widely acknowledged as a dielectric elastomer with exceptional electromechanical actuation performance than its counterparts. However, actuation in VHB elastomers is well-known to be enhanced by cross-linkers and plasticizers, the impacts of particulate fillers on their structure, properties, and performance are yet to be recognized. This work addresses the influences of barium titanate (BT) and Ketjenblack (KB) dispersed trimethylolpropane trimethacrylate (TMPTMA) as fillers on the behavior of VHB 4910 elastomer for the planar actuators. The elastomer composites are prepared by swelling and then thermochemical curing of the samples in BT and KB dispersed TMPTMA. The incorporation of fillers in the elastomer matrix is confirmed by comparing optical micrographs, swelling degree, cross-link density, molecular bonds, optical bandgap, and opto-dielectric characteristics. Thus, the dielectric and mechanical behavior and electromechanical actuation performance of the filler-reinforced elastomer are discussed. Improved dielectric constant and specifically reduced elastic modulus are witnessed due to the gelation of TMPTMA leading to a new range of actuation in VHB 4910 elastomer. The areal actuation in elastomer comprising BT, KB and BT-KB particle dispersed TMPTMA is estimated at about 180%, 150% and 165%, respectively. The low electric field requirement is noticed for BT-containing elastomer composite. This work scopes the use of swelling techniques to modify microporous elastomers with particulate fillers towards soft actuators, sensors, and energy generators.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1047 - 1064"},"PeriodicalIF":2.4,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reactive extrusion foaming of poly(lactic acid): tailoring foam properties through controlling in-process chemical reactions 聚乳酸的反应性挤压发泡：通过控制加工过程中的化学反应定制泡沫特性

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-01 DOI: 10.1007/s13726-024-01304-x

Maryam Valipour, Mahdi Rahmanifard, Navid Jaberi, Alireza Shadman, Mehdi Hatami, Hossein Ali Khonakdar, Farkhondeh Hemmati

{"title":"Reactive extrusion foaming of poly(lactic acid): tailoring foam properties through controlling in-process chemical reactions","authors":"Maryam Valipour, Mahdi Rahmanifard, Navid Jaberi, Alireza Shadman, Mehdi Hatami, Hossein Ali Khonakdar, Farkhondeh Hemmati","doi":"10.1007/s13726-024-01304-x","DOIUrl":"10.1007/s13726-024-01304-x","url":null,"abstract":"<div><p>A continuous extrusion foaming process was performed on poly(lactic acid) (PLA) in the presence of different chemical foaming agents (CFAs) and a chain extender additive using different extruder barrel and die temperature profiles. Chemical reactions, which are involved in the extrusion foaming process of PLA, are intensely investigated to control the reactive extrusion process and tailor the foam final properties. A set of experiments was designed using the response surface methodology to evaluate the effects of material and processing parameters and optimize the PLA foam property. The results showed that the maximum void fraction, i.e. 0.55, was obtained by exothermic CFA at higher extruder temperatures. In contrast to the exothermic CFA, the addition of endothermic CFAs did not result in lightweight biodegradable foams. The void fractions of these extruded foams were less than 0.05. The presence of water molecules as a by-product of the decomposition reaction and also relatively lower decomposition temperatures of the endothermic CFAs have been considered as the main reasons. Among the variables studied, the CFA type had the strongest impact on the foam properties. In the second step, the barrel and die temperatures were adjusted accordingly.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1031 - 1046"},"PeriodicalIF":2.4,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical and thermal investigation of high-density polyethylene/multi-walled carbon nanotube/tungsten disulfide hybrid composites 高密度聚乙烯/多壁碳纳米管/二硫化钨混合复合材料的力学和热学研究

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-04-01 DOI: 10.1007/s13726-024-01305-w

Sampath Kumar Sudarsanam, K. Panneerselvam

{"title":"Mechanical and thermal investigation of high-density polyethylene/multi-walled carbon nanotube/tungsten disulfide hybrid composites","authors":"Sampath Kumar Sudarsanam, K. Panneerselvam","doi":"10.1007/s13726-024-01305-w","DOIUrl":"10.1007/s13726-024-01305-w","url":null,"abstract":"<div><p>This study investigates the impact of addition of different weight percentages of tungsten disulphide (WS<sub>2</sub>) lubricant on the thermal and mechanical properties of high density polyethylene (HDPE) hybrid composites reinforced with a multi-walled carbon nanotube (MWCNT). HDPE composites were fabricated using a twin-screw extruder process employed to add reinforcement and lubricants in different weight percentages (%, by weight). X-ray diffraction (XRD) patterns indicated the distribution and dispersion of filler materials in the HDPE matrix. The quality of the composite was investigated by measuring the mechanical properties such as impact strength, hardness, tensile strength, and flexural strength. Thermogravimetric analysis (TGA) was employed to examine the thermal stability of the composite material. Main decomposition temperatures were determined using derivative thermogravimetry (DTG) analysis. Thermal transitions and degree of crystallisation (<i>X</i><sub>c</sub>) of the polymeric materials used were investigated by using differential scanning calorimetry (DSC) technique. The lubricant was added in three varying amounts of 2%, 4% and 8% (by weight) whilst MWCNT was maintained at 1% (by weight). The experimental results revealed that the composite with 2% (by weight) of WS<sub>2</sub> provides better mechanical properties such as impact strength, flexural strength, tensile strength, and hardness. With an increase in lubricant percentage, agglomeration of particles is found to be dominant in the composite, and the composite with 4% (by weight) of WS<sub>2</sub> displays better thermal properties, as determined using TGA, DTG and DSC analytical techniques.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1075 - 1089"},"PeriodicalIF":2.4,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced smoke/toxicity suppression of intumescent flame retardant thermoplastic polyurethane composites with the addition of graphene 添加石墨烯增强膨胀阻燃热塑性聚氨酯复合材料的烟雾/毒性抑制能力

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-03-30 DOI: 10.1007/s13726-024-01303-y

Leila Taghi-Akbari, Mohammad Reza Naimi-Jamal, Shervin Ahmadi, Saeed Bakhtiyari

{"title":"Enhanced smoke/toxicity suppression of intumescent flame retardant thermoplastic polyurethane composites with the addition of graphene","authors":"Leila Taghi-Akbari, Mohammad Reza Naimi-Jamal, Shervin Ahmadi, Saeed Bakhtiyari","doi":"10.1007/s13726-024-01303-y","DOIUrl":"10.1007/s13726-024-01303-y","url":null,"abstract":"<div><p>High flame retardancy with significant suppression of toxic smoke and melt-dripping are challenging issues associated with flame-retardant thermoplastic polyurethane (TPU). To address these issues, in this work, graphene (Gr) was used as an effective two-dimensional smoke-toxicity suppressant with loadings less than 1 wt%, in combination with two efficient intumescent flame retardant (IFR) systems reported in our previous works. The IFRs were consisted of ammonium polyphosphate, pentaerythritol (PER), and melamine polyphosphate (MPP) with MPP:PER ratios of 10:1 (IFR1) and 1:1 (IFR2). Cone calorimeter test (CCT) results showed outstanding flame retardancy and excellent toxic smoke suppression in TPU/IFR1/0.75%Gr sample with reduced peak heat release rate (PHRR) by 85.3%, peak smoke production rate (PSPR) by 92.1%, and peak carbon monoxide production (PCOP) by 91.3% compared with neat TPU. TPU/IFR2/0.5%Gr sample exhibited a similar trend, with the PHRR, PSPR, and PCOP reduced by 66.8%, 62.5%, and 64.0%, respectively, with good anti-dripping property. The barrier function of graphene had a significant influence on reducing total smoke released in TPU/IFR1/0.75%Gr and TPU/IFR2/0.5%Gr samples by 82.1% and 34.3%, respectively, compared with their related TPU/IFRs composites. TPU nanocomposites reached a UL-94 V-0 rating and LOI of more than 29%. TGA results indicated improved char-forming, and FESEM depicted the graphitized integrated char structures. Mechanical performance of TPU/IFR2/0.5%Gr exhibited an enhanced ductility compared with the neat TPU. The possible flame retardancy mechanism was proposed based on the data obtained from the CCT, TGA, and EDS elemental analysis.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1129 - 1142"},"PeriodicalIF":2.4,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140362954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microwave-assisted aggregation of CO2-switchable polystyrene latexes prepared through emulsion polymerization using cationic stabilizers 使用阳离子稳定剂通过乳液聚合法制备的二氧化碳可切换聚苯乙烯胶乳的微波辅助聚合反应

IF 2.4 3区化学

Iranian Polymer Journal Pub Date : 2024-03-30 DOI: 10.1007/s13726-024-01302-z

Sajad Avar, Abbas Rezaee Shirin-Abadi

{"title":"Microwave-assisted aggregation of CO2-switchable polystyrene latexes prepared through emulsion polymerization using cationic stabilizers","authors":"Sajad Avar, Abbas Rezaee Shirin-Abadi","doi":"10.1007/s13726-024-01302-z","DOIUrl":"10.1007/s13726-024-01302-z","url":null,"abstract":"<div><p>Microwave irradiation (MWI) is introduced as a novel trigger to aggregate CO<sub>2</sub>-switchable latexes. The polystyrene (PS) latexes were synthesized through emulsion polymerization in two ways (using polar monomer 2-dimethylaminoethyl methacrylate (DMAEMA) (as in situ copolymerization), and a well-defined block copolymer, poly(dimethylaminoethyl methacrylate-block-methyl methacrylate), PDMAEMA-<i>b</i>-PMMA as positively charged stabilizing moieties in the presence of 4,4'-(diazene-1,2-diyl) bis(<i>N</i>-(3-(dimethylamino) propyl)-4-methylpentanamide) (DABPA) as an “inistab” (initiator + colloidal stabilizer). Since the polymerization was conducted in acidic media using hydrochloric acid (HCl) to protonate stabilizers, PS latexes could be simply destabilized by adding NaOH. The destabilized latexes were redispersed by introducing CO<sub>2</sub> plus sonication to yield CO<sub>2</sub>-switchable latexes. The particle size of the resultant latexes after redispersion was very similar to that of primary latexes, as measured by dynamic light scattering. MWI and conventional heating (CH) stimuli were applied to aggregate the CO<sub>2</sub>-switchable PS latex particles. The influence of different factors on the time required for aggregation and particle size changes of the synthesized latexes was studied. These two methods of destabilization of PS latexes produce completely different switching behavior. Findings revealed that microwave-assisted aggregation (MAA) relative to CH required less time, but an increase in particle size of the redispersed particles in comparison to the original latexes was observed. Therefore, MAA can be assumed as a promising trigger for the aggregation of CO<sub>2</sub>-responsive latexes. This facile aggregation process, which could reduce time and energy input, might be of high interest and importance in various applications.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 8","pages":"1017 - 1030"},"PeriodicalIF":2.4,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140363188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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