To improve the processability of biphenyl phthalonitrile resin, a flexible siloxane structure was introduced into the phthalonitrile monomer through molecular design, which was then blended with a biphenyl monomer to prepare phthalonitrile alloy resins. When the ratio of phthalonitrile monomer containing flexible siloxane to biphenyl phthalonitrile monomer was 1:1, the processing window widened from 58 to 110°C, as compared to that of biphenyl phthalonitrile. Due to the introduction of the biphenyl structure into the phthalonitrile alloy resins, the initial decomposition temperature of the silicon-containing phthalonitrile resin increased from 385 to 516°C. More importantly, the phthalonitrile alloy resin exhibited a high bending strength (66 MPa) and bending modulus (3762 MPa), indicating that it could be potentially applied as high temperature structural composite matrices. Furthermore, it provides a new strategy for processing phthalonitrile resins with a high melting point and narrow processing window.
{"title":"Preparation of phthalonitrile resins containing siloxane linkages with improved processability","authors":"Weihao Yin, X. Sang, Jinghui Dong, Zhen Chen, X. Chen","doi":"10.1177/09540083231162521","DOIUrl":"https://doi.org/10.1177/09540083231162521","url":null,"abstract":"To improve the processability of biphenyl phthalonitrile resin, a flexible siloxane structure was introduced into the phthalonitrile monomer through molecular design, which was then blended with a biphenyl monomer to prepare phthalonitrile alloy resins. When the ratio of phthalonitrile monomer containing flexible siloxane to biphenyl phthalonitrile monomer was 1:1, the processing window widened from 58 to 110°C, as compared to that of biphenyl phthalonitrile. Due to the introduction of the biphenyl structure into the phthalonitrile alloy resins, the initial decomposition temperature of the silicon-containing phthalonitrile resin increased from 385 to 516°C. More importantly, the phthalonitrile alloy resin exhibited a high bending strength (66 MPa) and bending modulus (3762 MPa), indicating that it could be potentially applied as high temperature structural composite matrices. Furthermore, it provides a new strategy for processing phthalonitrile resins with a high melting point and narrow processing window.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46333164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phthalonitrile monomer with alkyl, pyrimidine, and amino is successfully prepared by nucleophilic substitution. The monomer is cured by autocatalysis of active hydrogen in the amino group, in order to obtain polymers through different temperature procedures. The low melting point (96°C) and curing kinetics of the monomer are analyzed by DSC, which manifest a processing window of 163°C. With lower energy barriers to overcome, the apparent activation energy (E a ) is 59.6 kJ mol−1 after fitting and calculating, signifying that the monomers are easier to process into polymers. This study focuses on the usefulness of the polymer, especially the long-term thermal stability by the comparison of numerous commonly used polymers. The consequence demonstrates that the polymer could be used for long periods at 300°C, keeping weight loss within 5 wt.% for 6 h. The advantage of long-term usage at high temperatures has not been proved in previous works on phthalonitrile polymer. Moreover, the thermal and thermal-mechanical stability are examined through TGA and DMA. The results indicate preferable thermal properties, that the glass transition temperature is up to 400°C.
{"title":"Self-catalytic phthalonitrile polymer with improved processing performance and long-term thermal stability","authors":"Xinyang Zhang, Xinyang Wang, Shuo Zhang, Minjie Wu, Jianxin Rong, Wenshuang Han, Tao Zhao, Xiaoyan Yu, Qingxin Zhang","doi":"10.1177/09540083231156818","DOIUrl":"https://doi.org/10.1177/09540083231156818","url":null,"abstract":"Phthalonitrile monomer with alkyl, pyrimidine, and amino is successfully prepared by nucleophilic substitution. The monomer is cured by autocatalysis of active hydrogen in the amino group, in order to obtain polymers through different temperature procedures. The low melting point (96°C) and curing kinetics of the monomer are analyzed by DSC, which manifest a processing window of 163°C. With lower energy barriers to overcome, the apparent activation energy (E a ) is 59.6 kJ mol−1 after fitting and calculating, signifying that the monomers are easier to process into polymers. This study focuses on the usefulness of the polymer, especially the long-term thermal stability by the comparison of numerous commonly used polymers. The consequence demonstrates that the polymer could be used for long periods at 300°C, keeping weight loss within 5 wt.% for 6 h. The advantage of long-term usage at high temperatures has not been proved in previous works on phthalonitrile polymer. Moreover, the thermal and thermal-mechanical stability are examined through TGA and DMA. The results indicate preferable thermal properties, that the glass transition temperature is up to 400°C.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45680308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-07DOI: 10.1177/09540083221149347
Guanghui Yang, Xin Ji
Both glass fiber (GF) and molybdenum disulfide (MoS2) can enhance the comprehensive properties of PTFE (polytetrafluoroethylene)-based composites, however the properties of the composites are significantly influenced by the molding pressure utilized. In this study, GF/MoS2/PTFE composites were produced under varied molding pressures (50–70 MPa), and the composites’ mechanical and tribological properties were evaluated. The results showed that the tribological parameters (such as friction coefficient and volumetric wear rate) and mechanical parameters (such as density, hardness, tensile strength, and elongation at break) varied depending on the molding pressure. When the molding pressure was 50 MPa, the GF/MoS2/PTFE composites displayed their finest mechanical properties. The composite had the best wear resistance with the lowest wear rate of only of 2.135 × 10−6 mm3/Nm at a molding pressure of 60 MPa and the lowest friction coefficient of 0.166 at a molding pressure of 70 MPa. The increased molding pressure that was employed to make the samples, as predicted by SEM analysis, would lead to greater residual stresses inside the specimens, which would ultimately result in cracking and peeling. In the friction test, specimens with a lower forming pressure are more likely to have surface furrows that are deeper and wider, as well as to shed their filler. Due to the increased molding pressure, the depth of furrows and filler shedding on the composite surface are also more apparent.
{"title":"Effect of different molding pressures on the properties of glass fiber / molybdenum disulfide / Polytetrafluoroethylene composites","authors":"Guanghui Yang, Xin Ji","doi":"10.1177/09540083221149347","DOIUrl":"https://doi.org/10.1177/09540083221149347","url":null,"abstract":"Both glass fiber (GF) and molybdenum disulfide (MoS2) can enhance the comprehensive properties of PTFE (polytetrafluoroethylene)-based composites, however the properties of the composites are significantly influenced by the molding pressure utilized. In this study, GF/MoS2/PTFE composites were produced under varied molding pressures (50–70 MPa), and the composites’ mechanical and tribological properties were evaluated. The results showed that the tribological parameters (such as friction coefficient and volumetric wear rate) and mechanical parameters (such as density, hardness, tensile strength, and elongation at break) varied depending on the molding pressure. When the molding pressure was 50 MPa, the GF/MoS2/PTFE composites displayed their finest mechanical properties. The composite had the best wear resistance with the lowest wear rate of only of 2.135 × 10−6 mm3/Nm at a molding pressure of 60 MPa and the lowest friction coefficient of 0.166 at a molding pressure of 70 MPa. The increased molding pressure that was employed to make the samples, as predicted by SEM analysis, would lead to greater residual stresses inside the specimens, which would ultimately result in cracking and peeling. In the friction test, specimens with a lower forming pressure are more likely to have surface furrows that are deeper and wider, as well as to shed their filler. Due to the increased molding pressure, the depth of furrows and filler shedding on the composite surface are also more apparent.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43988139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-02DOI: 10.1177/09540083231155066
N. Karaca
In this study, a novel bismaleimide monomer: Carbazole-Bismaleimide (Cz-BisMI) was introduced to the literature as a first. Cz-BisMI was synthesized by a catalytic cyclodehydration reaction of 3,6-bismalemic acid carbazole which is an intermediate product obtained by an imidization reaction of 3,6-diamino carbazole. Then, the chemical structure of Cz-BisMI was elucidated by FT-IR, 1H NMR, 13C NMR and LC-MS spectroscopies. The thermal properties of Cz-BisMI were investigated by DSC in comparison with a commercial bismaleimide monomer, 4,4-bismaleimidophenylmethane (DPM-BisMI). Cz-BisMI has a melting point of 192°C and also, the onset temperature of the exothermic curve was measured as 293°C. Furthermore, it was determined that Cz-BisMI has a 35.6 percent larger processing window than DPM-BisMI. The spin-coated films of Cz-BisMI showed a high refractive index in the range of 1.61 to 1.50 between 400 and 650 nm with good transparency of over 85%. On the other hand, a new poly(bismaleimide): P(Cz-BisMI)s containing carbazole units was prepared by the self-polymerization process of Cz-BisMI. P(Cz-BisMI)s showed a high thermal transition temperature of 356°C. In conclusion, Cz-BisMI is a viable choice as a bismaleimide monomer for the development of opto-electronic materials due to its enhanced optical properties and thermal behavior.
{"title":"A novel carbazole based bismaleimide monomer: Synthesis, characterization, thermal and optical properties","authors":"N. Karaca","doi":"10.1177/09540083231155066","DOIUrl":"https://doi.org/10.1177/09540083231155066","url":null,"abstract":"In this study, a novel bismaleimide monomer: Carbazole-Bismaleimide (Cz-BisMI) was introduced to the literature as a first. Cz-BisMI was synthesized by a catalytic cyclodehydration reaction of 3,6-bismalemic acid carbazole which is an intermediate product obtained by an imidization reaction of 3,6-diamino carbazole. Then, the chemical structure of Cz-BisMI was elucidated by FT-IR, 1H NMR, 13C NMR and LC-MS spectroscopies. The thermal properties of Cz-BisMI were investigated by DSC in comparison with a commercial bismaleimide monomer, 4,4-bismaleimidophenylmethane (DPM-BisMI). Cz-BisMI has a melting point of 192°C and also, the onset temperature of the exothermic curve was measured as 293°C. Furthermore, it was determined that Cz-BisMI has a 35.6 percent larger processing window than DPM-BisMI. The spin-coated films of Cz-BisMI showed a high refractive index in the range of 1.61 to 1.50 between 400 and 650 nm with good transparency of over 85%. On the other hand, a new poly(bismaleimide): P(Cz-BisMI)s containing carbazole units was prepared by the self-polymerization process of Cz-BisMI. P(Cz-BisMI)s showed a high thermal transition temperature of 356°C. In conclusion, Cz-BisMI is a viable choice as a bismaleimide monomer for the development of opto-electronic materials due to its enhanced optical properties and thermal behavior.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41760592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyarylates containing phthalazinone moieties are synthesized by interfacial polymerization of 2,4-(4-hydroxyphenyl)-2,3-phthalazin-1-one with isophthaloyl dichloride (IPC) and terephthaloyl dichloride (TPC). The effects of organic solvents and phase transfer catalysts (PTC) on the intrinsic viscosity (η int ) are systematically investigated for polymers with η int up to 1.52 dL g−1. The polyarylate has a high η int with 1,2-dichloroethane and cetyltrimethylammonium bromide used as the organic phase solvent and PTC. It is found that polyarylates prepared from BPPZ with IPC and TPC have excellent thermal resistance, with glass transition temperatures of 292 and 337°C, respectively. The polyarylates exhibit excellent thermal stability with 5% mass-loss temperature above 469°C in both N2 and air, and residual mass ratios at 800°C in N2 and air above 54.1% and 4.0%, respectively.
{"title":"Polyarylates containing phthalazinone moieties with excellent thermal resistance","authors":"Peiqi Xu, Shou-hai Zhang, Qian Liu, Kai-wen Wu, Danhui Wang, Zhaoqi Wang, Ze-yuan Liu, Ying-nan Zhang, X. Jian","doi":"10.1177/09540083231155067","DOIUrl":"https://doi.org/10.1177/09540083231155067","url":null,"abstract":"Polyarylates containing phthalazinone moieties are synthesized by interfacial polymerization of 2,4-(4-hydroxyphenyl)-2,3-phthalazin-1-one with isophthaloyl dichloride (IPC) and terephthaloyl dichloride (TPC). The effects of organic solvents and phase transfer catalysts (PTC) on the intrinsic viscosity (η int ) are systematically investigated for polymers with η int up to 1.52 dL g−1. The polyarylate has a high η int with 1,2-dichloroethane and cetyltrimethylammonium bromide used as the organic phase solvent and PTC. It is found that polyarylates prepared from BPPZ with IPC and TPC have excellent thermal resistance, with glass transition temperatures of 292 and 337°C, respectively. The polyarylates exhibit excellent thermal stability with 5% mass-loss temperature above 469°C in both N2 and air, and residual mass ratios at 800°C in N2 and air above 54.1% and 4.0%, respectively.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43268253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-22DOI: 10.1177/09540083231153336
Xiong Yang, Maoyong Zhi, Yuchuan Li, Hui Xin, Rong Fan, Xiantao Chen, Quanyi Liu, Yuanhua He
Phenolic resin (PF) is widely used in aerospace, composite materials, and other fields. However, large amount of heat and smoke are produced during its combustion process, which is an important factor limiting its usage. To solve this problem, additive flame retardant MoO3 has been incorporated into PF for improving its flame retardancy and smoke suppression properties. Thermogravimetric analyses results show that the T5% of PF composites was gradually decreased from 264°C to 184°C and the char yield of PF-10% MoO3 is 57 wt.%, higher than that of neat PF (50 wt.%). The PF composites with 10 wt.% MoO3 passed UL-94 V-0 rating with a limiting oxygen index value of 29.8%. Meanwhile, the total heat release and total smoke production of PF-10% MoO3 are 37.60 MJ/m2 and 5.79 m2 respectively, which are reduced by 30.5% and 24.8% compared with neat PF. Only 10 wt.% MoO3 provide a 56.5% reduction (from 255 to 111) in maximal smoke density, meaning the good smoke suppression properties of MoO3. The pyrolysis products components are determined by thermogravimetric analysis combined with Fourier transform infrared spectroscopy. Furthermore, the micromorphology and chemical structure of char residue are also investigated by scanning electron microscopy, x-ray diffraction and Raman spectroscopy techniques. The promoting carbonization effect of MoO3 significantly reduces the heat release and toxic smoke production of PF composites.
{"title":"Improved flame retardancy and smoke suppression properties of phenolic resin by incorporating MoO3 particles","authors":"Xiong Yang, Maoyong Zhi, Yuchuan Li, Hui Xin, Rong Fan, Xiantao Chen, Quanyi Liu, Yuanhua He","doi":"10.1177/09540083231153336","DOIUrl":"https://doi.org/10.1177/09540083231153336","url":null,"abstract":"Phenolic resin (PF) is widely used in aerospace, composite materials, and other fields. However, large amount of heat and smoke are produced during its combustion process, which is an important factor limiting its usage. To solve this problem, additive flame retardant MoO3 has been incorporated into PF for improving its flame retardancy and smoke suppression properties. Thermogravimetric analyses results show that the T5% of PF composites was gradually decreased from 264°C to 184°C and the char yield of PF-10% MoO3 is 57 wt.%, higher than that of neat PF (50 wt.%). The PF composites with 10 wt.% MoO3 passed UL-94 V-0 rating with a limiting oxygen index value of 29.8%. Meanwhile, the total heat release and total smoke production of PF-10% MoO3 are 37.60 MJ/m2 and 5.79 m2 respectively, which are reduced by 30.5% and 24.8% compared with neat PF. Only 10 wt.% MoO3 provide a 56.5% reduction (from 255 to 111) in maximal smoke density, meaning the good smoke suppression properties of MoO3. The pyrolysis products components are determined by thermogravimetric analysis combined with Fourier transform infrared spectroscopy. Furthermore, the micromorphology and chemical structure of char residue are also investigated by scanning electron microscopy, x-ray diffraction and Raman spectroscopy techniques. The promoting carbonization effect of MoO3 significantly reduces the heat release and toxic smoke production of PF composites.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49346905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-13DOI: 10.1177/09540083221151013
J. Jayakanth, K. Chennakesavulu, G. Ramanjaneya Reddy, S. Dhanalakshmi, V. Priya, K. Sasikumar, T. Sasipraba
The multiwall carbon nanotubes (MWCNTs) were grown by CVD method and using Ni impregnated zeolite as a substrate. The prepared MWCNT diameter varied from 10 to 60 nm and length in few microns. The silicone rubber (SR) was mixed well with conductive carbon, Polyaniline (PANI) and MWCNTs in two roll mill. The prepared silicone rubber materials were fabricated in the form of sheets with dimensions of 200 mm × 200 mm × 2 mm by using compression molding technique. The prepared sheets were subjected for EMI shielding efficiency measurements at low frequency (< 1.5 GHz) and high frequency range from 1 GHz to 18 GHz. At high frequency the shielding effectiveness of the Conducting Silicone Rubber and Conductive silicone rubber with MWCNT was found to be 24 dB and 48 dB. The volume resistivity measurements were also carried for all the prepared silicone rubber sheets, the results reveals that SR + MWCNT, CSR + MWCNT composites shows volume resistivity 4032 and 20.7 Ω.cm respectively. This confirms the conductivity of CSR + MWCNT is enough to exhibit good Shielding Effectiveness. Graphical Abstract
{"title":"A study on development of silicone rubber with conductive carbon, polyaniline, MWCNT composite for EMI shielding","authors":"J. Jayakanth, K. Chennakesavulu, G. Ramanjaneya Reddy, S. Dhanalakshmi, V. Priya, K. Sasikumar, T. Sasipraba","doi":"10.1177/09540083221151013","DOIUrl":"https://doi.org/10.1177/09540083221151013","url":null,"abstract":"The multiwall carbon nanotubes (MWCNTs) were grown by CVD method and using Ni impregnated zeolite as a substrate. The prepared MWCNT diameter varied from 10 to 60 nm and length in few microns. The silicone rubber (SR) was mixed well with conductive carbon, Polyaniline (PANI) and MWCNTs in two roll mill. The prepared silicone rubber materials were fabricated in the form of sheets with dimensions of 200 mm × 200 mm × 2 mm by using compression molding technique. The prepared sheets were subjected for EMI shielding efficiency measurements at low frequency (< 1.5 GHz) and high frequency range from 1 GHz to 18 GHz. At high frequency the shielding effectiveness of the Conducting Silicone Rubber and Conductive silicone rubber with MWCNT was found to be 24 dB and 48 dB. The volume resistivity measurements were also carried for all the prepared silicone rubber sheets, the results reveals that SR + MWCNT, CSR + MWCNT composites shows volume resistivity 4032 and 20.7 Ω.cm respectively. This confirms the conductivity of CSR + MWCNT is enough to exhibit good Shielding Effectiveness. Graphical Abstract","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45649866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1177/09540083221149344
Abdelwahed Berrouane, M. Derradji, Karim Khiari, Bouchra Amri, Oussama Mehelli, S. Abdous, Abdeljalil Zegaoui, Noureddine Ramdani, Raouf Belgacemi, Wen-ben Liu
In this study, a new strategy is adopted for the development of advanced, and lightweight ballistic armor. This new generation of ballistic protections is referred to as “hybrid”, in which certain layers of Kevlar have been impregnated with a high-performance green and bisphenol-A free thermosetting resin, namely the vanillin-based benzoxazine (Va-BZ). The role of thermosetting polymer is to slow down and stop the projectile. In addition, the backface signature (BFS) with a minimum number of Kevlar layers is reduced. Indeed, this kind of matrix not only possesses one of the highest crosslinking densities in the field, but also offers excellent mechanical and thermal properties. The adopted experimental approach consists in gradually changing, in increments of 5, the number of impregnated Kevlar layers. The ultimate goal is to reduce the number of Kevlar layers from 26 (currently in use) to 20 while ensuring a BFS of less than 44 mm (as per the requirement of the National Institute of Justice standard NIJ-0101.06). Indeed, the adopted strategy allowed significant reduction in the BFS. For instance, armors made of 20 layers of Kevlar layers in which 10 layers were impregnated by the Va-BZ displayed the minimal BFS value of 36.54 mm. Hence, by introducing the Va-BZ resin, the non-perforated Kevlar fabrics gained enough rigidity to sustain the impact with minimal deformation. Overall, these newly developed armors offer the best BFS possible to protect vital human body parts.
{"title":"New strategy for the development of lightweight ballistic armors with limited backface signature","authors":"Abdelwahed Berrouane, M. Derradji, Karim Khiari, Bouchra Amri, Oussama Mehelli, S. Abdous, Abdeljalil Zegaoui, Noureddine Ramdani, Raouf Belgacemi, Wen-ben Liu","doi":"10.1177/09540083221149344","DOIUrl":"https://doi.org/10.1177/09540083221149344","url":null,"abstract":"In this study, a new strategy is adopted for the development of advanced, and lightweight ballistic armor. This new generation of ballistic protections is referred to as “hybrid”, in which certain layers of Kevlar have been impregnated with a high-performance green and bisphenol-A free thermosetting resin, namely the vanillin-based benzoxazine (Va-BZ). The role of thermosetting polymer is to slow down and stop the projectile. In addition, the backface signature (BFS) with a minimum number of Kevlar layers is reduced. Indeed, this kind of matrix not only possesses one of the highest crosslinking densities in the field, but also offers excellent mechanical and thermal properties. The adopted experimental approach consists in gradually changing, in increments of 5, the number of impregnated Kevlar layers. The ultimate goal is to reduce the number of Kevlar layers from 26 (currently in use) to 20 while ensuring a BFS of less than 44 mm (as per the requirement of the National Institute of Justice standard NIJ-0101.06). Indeed, the adopted strategy allowed significant reduction in the BFS. For instance, armors made of 20 layers of Kevlar layers in which 10 layers were impregnated by the Va-BZ displayed the minimal BFS value of 36.54 mm. Hence, by introducing the Va-BZ resin, the non-perforated Kevlar fabrics gained enough rigidity to sustain the impact with minimal deformation. Overall, these newly developed armors offer the best BFS possible to protect vital human body parts.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49358943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-29DOI: 10.1177/09540083221148390
Rinku Pramanick, S. Verma, R. Kumari, S. De, S. Neogi, S. Neogi
Microstructural variations have a strong influence on the load transfer capacity of the high-performance polymeric fibers, which is also reflected in their ballistic property changes. The focus of the present study is to investigate thermally induced microstructural changes and their reflection on the mechanical properties and theoretical ballistic limit of poly (p-phenylene terephthalamide) fibers by a correlation. From the quantitative analysis of XRD, thermally induced changes in unit cell a-dimension show profound sensitivity in affecting the tenacity and modulus of the fibers. Based on the physicochemical changes in FTIR and FESEM analysis, significant surface deterioration and changes in the chemical network are observed. However, dimensional variations of the crystal structure along a-direction show a stronger influence than the chemical and morphological changes, reflecting sigmoidal responses with tenacity, modulus and theoretical V50 by correlations. As an effect of unit cell dimensional variation, changes in crystallinity are resulted and lead to the loss in theoretical ballistic limit of the fibers by following first-order kinetics. Lastly, angular separation and (200) orientation angle are determined to build a global correlation with modulus and theoretical ballistic limit for quickly decoding macro-changes in terms of micro-properties. The given correlations can help to identify crystallographic transformations upon other induction techniques and view their effect on mechanical and ballistic parameters. In addition, the given approach can be extended for different ballistic materials under any environmental conditions. Graphical Abstract
{"title":"Effect of thermally induced microstructural changes on the mechanical properties and ballistic performance of poly (p-phenylene terephthalamide) fibers","authors":"Rinku Pramanick, S. Verma, R. Kumari, S. De, S. Neogi, S. Neogi","doi":"10.1177/09540083221148390","DOIUrl":"https://doi.org/10.1177/09540083221148390","url":null,"abstract":"Microstructural variations have a strong influence on the load transfer capacity of the high-performance polymeric fibers, which is also reflected in their ballistic property changes. The focus of the present study is to investigate thermally induced microstructural changes and their reflection on the mechanical properties and theoretical ballistic limit of poly (p-phenylene terephthalamide) fibers by a correlation. From the quantitative analysis of XRD, thermally induced changes in unit cell a-dimension show profound sensitivity in affecting the tenacity and modulus of the fibers. Based on the physicochemical changes in FTIR and FESEM analysis, significant surface deterioration and changes in the chemical network are observed. However, dimensional variations of the crystal structure along a-direction show a stronger influence than the chemical and morphological changes, reflecting sigmoidal responses with tenacity, modulus and theoretical V50 by correlations. As an effect of unit cell dimensional variation, changes in crystallinity are resulted and lead to the loss in theoretical ballistic limit of the fibers by following first-order kinetics. Lastly, angular separation and (200) orientation angle are determined to build a global correlation with modulus and theoretical ballistic limit for quickly decoding macro-changes in terms of micro-properties. The given correlations can help to identify crystallographic transformations upon other induction techniques and view their effect on mechanical and ballistic parameters. In addition, the given approach can be extended for different ballistic materials under any environmental conditions. Graphical Abstract","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41663246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-26DOI: 10.1177/09540083221148392
Changxin Wan, D. Jia, S. Zhan, Wu Zhang, Tian Yang, Yinhua Li, Jian Li, H. Duan
A compacted body was fabricated by pulverulent polyimide (PI) block copolymers using solid-like state compression molding (SCM) technique. Polymer heated to solid-like state, i.e. the high-elastic non-melting state above the glass transition temperature (Tg) and well below melting temperature, could achieve plasticity due to dramatic decreases in elastic modulus. Tensile properties were taken as response values, and the results of single-factor experiments indicated that molding temperature was the dominant parameter on mechanical performances, followed by molding pressure and holding time. Within this context, the SCM process possesses a longer processing time window whereas the processing temperature is narrow. The manufacturing defects induced by inappropriate processing conditions also hurt the tribological performance of PIs. Particles in a solid-like state could coalesce tightly only by exerting both high temperature and pressure in the SCM process. Thermoforming mechanism examined by atomic-scale molecular dynamics simulation indicated that non-bonding interaction forces, especially van der Waals forces play a key role in fusing among polymeric particles. This study is devoted to establishing the interdependence of structure-formability-property for high-temperature polymers that are not melt processible.
{"title":"Property investigation for high-Performance Polyimides fabricated via compression molding in solid-like state","authors":"Changxin Wan, D. Jia, S. Zhan, Wu Zhang, Tian Yang, Yinhua Li, Jian Li, H. Duan","doi":"10.1177/09540083221148392","DOIUrl":"https://doi.org/10.1177/09540083221148392","url":null,"abstract":"A compacted body was fabricated by pulverulent polyimide (PI) block copolymers using solid-like state compression molding (SCM) technique. Polymer heated to solid-like state, i.e. the high-elastic non-melting state above the glass transition temperature (Tg) and well below melting temperature, could achieve plasticity due to dramatic decreases in elastic modulus. Tensile properties were taken as response values, and the results of single-factor experiments indicated that molding temperature was the dominant parameter on mechanical performances, followed by molding pressure and holding time. Within this context, the SCM process possesses a longer processing time window whereas the processing temperature is narrow. The manufacturing defects induced by inappropriate processing conditions also hurt the tribological performance of PIs. Particles in a solid-like state could coalesce tightly only by exerting both high temperature and pressure in the SCM process. Thermoforming mechanism examined by atomic-scale molecular dynamics simulation indicated that non-bonding interaction forces, especially van der Waals forces play a key role in fusing among polymeric particles. This study is devoted to establishing the interdependence of structure-formability-property for high-temperature polymers that are not melt processible.","PeriodicalId":12932,"journal":{"name":"High Performance Polymers","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46209609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：