POLYMER INTERNATIONAL
·
2018
·Vol. 67
·期 9
·1221-1228
·
IF 2.352
Meng Ma,Kai Liu,Haiming Zheng,Si Chen,Bozhen Wu,Yanqin Shi,Xu Wang
Poly( l -lactic acid)/crosslinked polyurethane (PLLA/CPU) blends which were prepared via reactive blending of PLLA with poly( ϵ -caprolactone) (PCL), glycerol and 4,4′-methylenediphenyl diisocyanate showed excellent toughness. The effects of the composition of the mixture and degree of crosslinking of CPU on the toughness of the PLLA/CPU blends (80/20 w/w) were studied in detail. Dynamic mechanical analysis and rheological measurements were used to characterize the structure of the in situ formed CPU in the PLLA matrix. A novel netlike phase structure was observed when the average molecular weight of PCL and degree of crosslinking were 1 kDa and 10%, respectively. The impact strength of the blend was enhanced from 2.2 kJ m −2 for pure PLLA to 62.4 kJ m −2 ; meanwhile, the elongation at break was increased to 489.8%. Therefore, the mechanical properties of PLLA/CPU blends can be easily tailored by tuning the composition of the mixture and the degree of crosslinking of CPU. © 2018 Society of Chemical Industry
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 10
·1663
·
IF 2.972
Yuanping Jiang,Cong Yan,Kai Wang,Dawei Shi,Zhengying Liu,Mingbo Yang
Polylactic acid (PLA) holds enormous potential as an alternative to the ubiquitous petroleum-based plastics to be used in packaging film and agricultural film. However, the poor viscoelastic behavior and its extremely low melt strength means it fails to meet the requirements in film blowing processing, which is the most efficient film processing method with the lowest costs. Also, the PLA’s brittleness and insufficient gas barrier properties also seriously limit PLA’s potential application as a common film material. Herein, special stereocomplex (SC) networks were introduced to improve the melt strength and film blowing stability of PLA; polyethylene glycol (PEG) was introduced to improve PLA’s toughness and gas barrier properties. Compared with neat poly(l-lactide) acid (PLLA), modified PLA is stable in the film blowing process and its film elongation at break increases more than 18 times and reaches over 250%, and its O2permeability coefficient decreased by 61%. The resulting film material also has good light transmittance, which has great potential for green packaging applications, such as disposable packaging and agricultural films.Keywords:PLA;biodegradable films;toughness;film blowing
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Wu Bin Ying,Zhe Yu,Do Hwan Kim,Kyung Jin Lee,Han Hu,Yiwei Liu,Zhengyang Kong,Kai Wang,Jie Shang,Ruoyu Zhang,Jin Zhu,Run-Wei Li
A stretchable electronic skin (e-skin) requires a durable elastomeric matrix to serve in various conditions. Therefore, excellent and balanced properties such as elasticity, water proof capability, toughness, and self-healing are demanded. However, it is very difficult and often contradictory to optimize them at one time. Here, a polyurethane (BS-PU-3) containing a polydisperse hard segment, hydrophobic soft segment, and a dynamic disulfide bond was prepared by one-pot synthesis. Unlike the normal two-pot reaction, BS-PU-3 obtained through the one-pot method owned a higher density of self-healing points along the main chain and a faster self-healing speed, which reached 1.11 μm/min in a cut-through sample and recovered more than 93% of virgin mechanical properties in 6 h at room temperature. Moreover, a remarkable toughness of 27.5 MJ/m3 assures its durability as an e-skin matrix. Even with a 1 mm notch (half of the total width) on a standard dumbbell specimen, it could still bear the tensile strain up to 324% without any crack propagation. With polybutadiene as the soft segment, the shape, microstructure, and conductivity in BS-PU-3 and BS-PU-3-based stretchable electronics kept very stable after soaking in water for 3 days, proving the super waterproof property. An e-skin demo was constructed, and self-healing in pressure sensitivity, mechanical, and electrical properties were verified.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Gels
·
2023
·Vol. 9
·期 2
·158
·
IF 4.6
Shilei Zhu,Dongdong Yan,Lin Chen,Yan Wang,Fengbo Zhu,Yanan Ye,Yong Zheng,Wenwen Yu,Qiang Zheng
The Kirigami approach is an effective way to realize controllable deformation of intelligent materials via introducing cuts into bulk materials. For materials ranging from ordinary stiff materials such as glass, ceramics, and metals to soft materials, including ordinary hydrogels and elastomers, all of them are all sensitive to the presence of cuts, which usually act as defects to deteriorate mechanical properties. Herein, we study the influence of the cuts on the mechanical properties by introducing “dispersed macro-scale cuts” into a model tough double network (DN) hydrogel (named D-cut gel), which consists of a rigid and brittle first network and a ductile stretchable second network. For comparison, DN gels with “continuous cuts” having the same number of interconnected cuts (named C-cut gel) were chosen. The fracture tests of D-cut gel and C-cut gel with different cut patterns were performed. The fracture observation revealed that crack blunting occurred at each cut tip, and a large wrinkle-like zone was formed where the wrinkles were parallel to the propagation direction of the cut. By utilizing homemade circular polarizing optical systems, we found that introducing dispersed cuts increases the rupture force by homogenizing the stress around the crack tip surrounding every cut, which reduces stress concentration in one certain cut. We believe this work reveals the fracture mechanism of tough soft materials with a kirigami cut structure, which should guide the design of advanced soft and tough materials along this line.Keywords:double-network hydrogels;cut dispersion;fracture;toughness
研究领域:
材料科学
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力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
·
IF 9.9
Kaili Gong,Lian Yin,Congling Shi,Xiaodong Qian,Keqing Zhou
It is challenging that the functionalized MXene-based nanofillers are designed to modify the inherent flammability and poor toughness of epoxy polymeric materials and further to facilitate the application of EP composites. Herein, silicon-reinforced Ti 3 C 2 T x MXene-based nanoarchitectures (MXene@SiO 2 ) are synthesized by simple self-growth method, and its enhancement effects on epoxy resin (EP) are investigated. The as-prepared nanoarchitectures realize homogeneous dispersion in EP matrix, indicating well performance-enhancing potential. The incorporation of MXene@SiO 2 achieves improved thermal stability for EP composites with higher T -5% and lower R max values. Moreover, EP/2 wt% MXene@SiO 2 composites obtain a 30.2% and 34.0% reduction in peak heat release rate (PHRR) and peak smoke production rate (PSPR) compared to those of pure EP, respectively, also achieving a 52.5% fall in smoke factor (SF) values and increased yield and stability of chars. The dual char-forming effects of MXene@SiO 2 nanoarchitectures, including the catalytic charring of MXene and the migration of SiO 2 to induce charring, are accounted for the results, as well as lamellar barrier effects. Additionally, EP/MXene@SiO 2 composites achieve an enhanced storage modulus of 51.5%, along with improved tensile strength and elongation at break, compared to those of pure EP.
研究领域:
材料科学
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复合材料工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
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2023
·Vol. 15
·期 3
·724
·
IF 5
Genxin Chen,Sijie Tang,Honghan Yan,Xiongbin Zhu,Huimin Wang,Liya Ma,Kang Mao,Changying Yang,Jiabing Ran
Currently, hydrogels simultaneously featuring high strength, high toughness, superior recoverability, and benign anti-fatigue properties have demonstrated great application potential in broad fields; thus, great efforts have been made by researchers to develop satisfactory hydrogels. Inspired by the double network (DN)-like theory, we previously reported a novel high-strength/high-toughness hydrogel which had two consecutive energy-dissipation systems, namely, the unzipping of coordinate bonds and the dissociation of the crystalline network. However, this structural design greatly damaged its stretchability, toughness recoverability, shape recoverability, and anti-fatigue capability. Thus, we realized that a soft/ductile matrix is indispensable for an advanced strong tough hydrogel. On basis of our previous work, we herein reported a modified energy-dissipation model, namely, a “binary DN-like structure” for strong tough hydrogel design for the first time. This structural model comprises three interpenetrated polymer networks: a covalent/ionic dually crosslinked tightened polymer network (stiff, first order network), a constrictive crystalline polymer network (sub-stiff, second order network), and a ductile/flexible polymer network (soft, third order network). We hypothesized that under low tension, the first order network served as the sacrificing phase through decoordination of ionic crosslinks, while the second order and third order networks together functioned as the elastic matrix phase; under high tension, the second order network worked as the energy dissipation phase (ionic crosslinks have been destroyed at the time), while the third order network played the role of the elastic matrix phase. Owing to the “binary DN-like” structure, the as-prepared hydrogel, in principle, should demonstrate enhanced energy dissipation capability, toughness/shape recoverability, and anti-fatigue/anti-tearing capability. Finally, through a series of characterizations, the unique “binary DN-like” structure was proved to fit well with our initial theoretical assumption. Moreover, compared to other energy-dissipation models, this structural design showed a significant advantage regarding comprehensive properties. Therefore, we think this design philosophy would inspire the development of advanced strong tough hydrogel in the future.Keywords:double-network;hydrogel;toughness
研究领域:
材料科学
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生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Yumiao Ma,Yikelamu Jilili,Tengfei Shao,Weijun Zhen
Poly(lactic acid) (PLA) has its own limitations in terms of slow crystallization rate and low crystallinity during processing, resulting in poor toughness and thermal stability , which seriously restricts the practical application of PLA. Blending nanoparticles into the PLA matrix is an effective way to improve PLA crystallization. In this study, carbon dots (CDs) were prepared by green oxidation using weathered coal as carbon source and then surface-modified with dodecylamine (DDA) and octadecylamine (ODA). Modified CDs (MCDs)/PLA composite films were prepared using MCDs as filler to improve the crystallinity and toughness of PLA films. The results showed that the improvement effect of ODA-modified CDs (ODACDs) was better than that of DDA-modified CDs (DDACDs). The crystallinity of PLA composite film (0.05 wt% ODACDs) was increased from 7.20% (pure PLA film) to 35.44%, and its elongation at break was increased by 5.01 times compared with that of the pure PLA film. Moreover, thermogravimetric analysis suggested that the thermal stability of MCDs/PLA films was also improved. The results of simultaneous rheology and in-situ FTIR analysis as well as molecular dynamics simulations confirmed that MCDs had a strong interaction with PLA molecules, which promoted the crystallization of PLA film, thereby improving its toughness and thermal stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Chunhui Luo,Shuai Xie,Xinyue Deng,Yan Sun,Yong Shen,Menglu Li,Wenxin Fu
The applications of hydrogels can be greatly expanded by the improvement of extensibility and toughness. Despite remarkable efforts in tough hydrogels, little is known about the fracture strain above 100 mm/mm due to the inhomogeneous chemical networks and inefficient energy-dissipative mechanism. Herein, micelle-like aggregates were obtained from the self-assembly of dually alkyl-modified polyethylene glycol (PEG) in water, serving as dynamic junctions to fabricate hydrogel via the aqueous radical polymerization of acrylamide (AM) monomers in water with the assistance of methylene bisacrylamide. Unlike hairy micelles, interactions of aggregates and hydrogel framworks were improved obviously through pronounced entanglements between PEG and PAM macromolecules. Meanwhile, the reversible break/reformation of micelle-like aggregates upon stretching empowered the gel an efficient energy-dissipative mechanism. Therefore, hydrogels with extreme stretchability (tensile strain = 150 mm/mm) and high toughness (toughness = 24.8 MJ/m 3 ) were generated. Remarkably, their mechanics could be easily modulated by varying alkyl terminals and molecular weights of PEG to control the strength of hydrophobic domains and physical entanglements, respectively. Two examples were displayed: ultra-sensitive gels for wearable sensors and mechano-responsive molecule release. Impressively, the gauge factor was 60.29 under large deformation (strain > 20 mm/mm), outperforming most conductive hydrogels. As the first research to tune the macroscopic property of the hydrogel by delicately adjusting the microstructures of micelles, and interactions between micelles and gel network, this work not only expands the applications of soft materials but also sheds light on fabricating super-stretchable matters, making it promising candidates for flexible sensors, artificial skins, and drug delivery systems.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Qing Wang,Ziyang Ruan,Jianyu Li,Zifan Zhao
Yttrium aluminum garnet (Y 3 Al 5 O 12 , YAG) is regarded as a candidate of thermal barrier coating material for its excellent thermal stability and corrosion resistance, yet the poor fracture toughness and the low thermal expansion coefficient are the roadblock that limits its application. In order to improve the fracture toughness and the thermal expansion coefficients, a series of Y 3 Al 5 O 12 composite ceramics toughened by ferroelastic LaAlO 3 second phase were prepared by in-situ synthesis method in this work. The prepared x LaAlO 3 /(1- x )Y 3 Al 5 O 12 composite ceramics ( x =10∼50%) exhibit superior fracture toughness (2.16 MPa·m 0.5 ∼2.63 MPa·m 0.5 ) with respect to single-phase Y 3 Al 5 O 12 (1.94 MPa·m 0.5 ), which is mainly attributed to the synergistic effects of ferroelastic toughening of second phase, residual stress toughening, and fine-grain strengthening. On the account of the synergistic effects of three toughening mechanisms, 0.2LaAlO 3 /0.8Y 3 Al 5 O 12 composite ceramic manifest the strongest fracture toughness (2.63 MPa·m 0.5 ), which is 36% improved compared with single-phase Y 3 Al 5 O 12 . In addition, the thermal expansion coefficients of x LaAlO 3 /(1- x )Y 3 Al 5 O 12 specimens (9.54∼9.97 × 10 -6 K -1 at 1200 °C) are larger than that of Y 3 Al 5 O 12 (9.25 × 10 -6 K -1 at 1200 °C). Especially, 0.5LaAlO 3 /0.5Y 3 Al 5 O 12 specimen exhibits the highest thermal expansion coefficient (9.97×10 -6 K -1 at 1200 °C), which improve by 7.78% compared to single-phase Y 3 Al 5 O 12 . The improved fracture toughness and the capable thermal expansion coefficients of LaAlO 3 /Y 3 Al 5 O 12 composite ceramics renders their promising aspect for thermal barrier coating application.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2025
·
IF 4.7
Xuejiao Peng,Huiwen He,Yulong Liu,Meng Ma,Yanqin Shi,Yulu Zhu,Si Chen,Xu Wang
The rigidity and toughness of the resin matrix significantly influence the impact resistance of ballistic composites. However, the relationship between the properties of the resin matrix and the ballistic performance of the composites remains inadequately defined. In this study, the ballistic performance of composites with various matrix resins was investigated to assess how matrix toughness affects energy absorption. A series of epoxy resins exhibiting different rigidity and toughness were combined with PBO (poly-p-phenyl-2,6-benzobisoxazole) fibers, and their quasi-static mechanical properties were evaluated to analyze their effectiveness in resisting ballistic impacts. In ballistic test, the brittle matrix composite demonstrated concentrated fiber breakage and localized damage, while the toughened matrix composite exhibited more dispersed damage characterized by reduced fiber breakage and minimal delamination, suggesting enhanced energy absorption via deformation within the matrix. Compared with the specific energy absorption value of the brittle matrix composite material, which is only 9.28 Jm 2 /kg, the specific energy absorption value of the tough matrix composite material has increased by 125% to 20.88 Jm 2 /kg. These findings underscore the critical role that matrix toughness plays in improving ballistic-resistant performance by facilitating better energy distribution while mitigating fiber damage. Highlights Matrix toughness significantly enhances ballistic energy absorption in composites. Toughened matrix reduces fiber breakage and delamination under ballistic impact. Toughened matrix composite achieves a 125% higher specific energy absorption. Findings offer insights for designing high-performance ballistic-resistant materials.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Dian Zhang,Xuan Liu,Yijun Liu
Conventional aluminum nitride (AlN) ceramics exhibited insufficient mechanical properties expected from their potential applications in the presence of dynamic loads and intensive stresses caused by thermal shock. In this study, the mechanical properties of AlN ceramics were enhanced by toughening them using AlN whiskers (AlN w ) via gel casting followed by low-temperature sintering at 1650°C. The addition of AlN w simultaneously increased the bending strength, toughness and thermal conductivity of the AlN ceramics. The maximum values of the bending strength, toughness, and thermal conductivity of 9.0 wt% AlN w /AlN were 303.92 MPa, 3.92 MPa·m 1/2 and 186.53 W·m −1 ·K −1 , respectively, which were higher than those of the AlN ceramics by 39.93%, 61.31% and, 15.61%, respectively. The AlN w in AlN w /AlN ceramics tightly bonded with the ceramic matrix, leading to two characteristic toughening mechanisms in the ceramics: crack pinning and deflection at irregular grain boundaries caused by doped whiskers, as well as bridging and stress relaxation caused by whiskers incorporated with the grains. Moreover, the one-dimensional morphology of AlN w can provide a channel for quick photon transport, thereby enhancing the thermal conductivity of AlN w /AlN.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Wenwen Wang,Aisen Jiang,Hao Zhang,Junjie Wang,Xiaoguang Li,Congang Fu,Xiaohan Yang,Ke Liu,Dong Wang
The growing demand for polymeric materials has encouraged industries and the academic community to develop materials with improved mechanical properties, particularly those that can be used in various fields. Polyamide 6 (PA6) is a versatile engineering plastic material with various advantageous properties; however, improving its toughness and hydrophobicity is conducive to expanding its application. In this work, α, ω-aminopropyl-terminated poly(methyltrifluoropropylsiloxane) prepolymer (APMFS) was synthesized for its outstanding flexibility and hydrophobicity. It was then covalently incorporated into a PA6 backbone through straightforward large-scale melt polymerization. The functionalized PA6 exhibited the highest breaking strength and toughness of approximately 59.6 MPa and 426.3 MJ/m3, respectively. Moreover, the impact strength of PA6-APMFS reached 63.7 kJ/m2, more than twice that of conventional PA6. The water contact angle was measured at its highest, 94°, with water absorption reduced to 0.5 wt %. Microfibers exhibited a very low wicking height of 7.5 cm. Subsequently, functionalized nanofibrous membranes and foams were applied for self-cleaning, oil/water separation, and thermal insulation, showcasing excellent potential for protective and water purification applications. This work illustrates the multifunctional application advantages of modified PA6.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）