Materials Today Communications
·
2021
·
IF 3.383
Guangzhi Jin,Yonglai Lu,Peng Yu,Liqun Zhang
Carbon dots (CDs) have attracted increasing attention as fluorescent agents for elastomer composites. Bottom-up synthesis of carbon dots (CDs) from molecular precursors would inevitably produce crude carbon dots (CCDs), i.e., a mixture of CDs, quasi CDs, polymer clusters, and molecular fluorophores. The CCDs are normally subjected to purification processes to obtain the pure CDs, while the purification procedures are time-consuming, expensive, and difficult to be scale-up. Herein, we directly used the CCDs as the fluorescent agents for silicon rubber. To achieve a good CCDs dispersion within the polymer matrix , we firstly prepared the CCDs fluid by mixing the CCDs solid with water, then the CCDs fluid was melt-mixed with the SiR (with the silica as filler) by a two-roll mill. The results revealed that small amounts of CCDs (less than 1 phr) could endow the matrix with intriguing luminescent property. Overall, this work offers a green and facile strategy to use CCDs as low-cost fluorescent agents for the SiR through melt-milling of CCDs fluid and rubber, which can be extended to a variety of other melt-processable polymer matrices (such as millable polyurethane rubber) and enables a broad range of potential applications.
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
Polymers
·
2020
·Vol. 12
·期 4
·892
·
IF 3.426
Rossella Arrigo,Mattia Bartoli,Giulio Malucelli
Biocomposites based on poly(lactic acid) (PLA) and biochar (BC) particles derived from spent ground coffee were prepared using two different processing routes, namely melt mixing and solvent casting. The formulated biocomposites were characterized through rheological, thermal, and mechanical analyses, aiming at evaluating the effects of the filler content and of the processing method on their final properties. The rheological characterization demonstrated the effectiveness of both exploited strategies in achieving a good level of filler dispersion within the matrix, notwithstanding the occurrence of a remarkable decrease of the PLA molar mass during the processing at high temperature. Nevertheless, significant alterations of the PLA rheological behavior were observed in the composites obtained by melt mixing. Differential scanning calorimetry (DSC) measurements indicated a remarkable influence of the processing method on the thermal behavior of biocomposites. More specifically, melt mixing caused the appearance of two melting peaks, though the structure of the materials remained almost amorphous; conversely, a significant increase of the crystalline phase content was observed for solvent cast biocomposites containing low amounts of filler that acted as nucleating agents. Finally, thermogravimetric analyses suggested a catalytic effect of BC particles on the degradation of PLA; its biocomposites showed decreased thermal stability as compared with the neat PLA matrix.Keywords:poly(lactic acid);biochar;melt mixing;solvent casting;rheological behavior;thermal properties
研究领域:
材料科学
·
环境科学
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DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2025
·
IF 4.7
Fangjuan Wu,Caofeng Ji,Haitao Huang,Huolin Zhong,Hui Fang
Highly thermally conductive polyamide 6 (PA6)/aluminum oxide (Al 2 O 3 )/graphene nanoplatelet (GNP) composites were fabricated through dynamic reactive blending. By utilizing the synergistic effect of low viscosity monomer and dynamic shear, uniform dispersion of Al 2 O 3 and GNP in the PA6 matrix was achieved, forming efficient thermal conductive networks. Structural and morphological analyses confirmed the homogeneous dispersion of fillers and good interfacial bonding characteristics. The results showed that when Al 2 O 3 and GNP contents were 43 and 7 wt%, respectively, the thermal conductivity reached 2.71 W/m·K, representing a 984% enhancement over neat PA6 and a 45.7% improvement compared to melt-blended composites. The P-S theoretical model was employed to understand the underlying mechanism, showing good agreement between theoretical calculations and experimental results. LED heat dissipation tests demonstrated excellent thermal response characteristics and temperature stability of the composites in practical thermal management applications, indicating their promising potential in electronic cooling applications. Highlights Dynamic reactive blending was used to prepare thermal conductive composites. Low viscosity of monomer and dynamic shear promoted uniform dispersion of fillers. The composites showed thermal conductivity of 2.71 W/m·K, 984% higher than neat PA6. P-S model showed enhanced parallel effect reduced interfacial thermal resistance. Composites demonstrated effective heat dissipation in LED thermal management tests.
研究领域:
材料科学
·
热管理技术
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产品关联
DOI
高影响因子
Advanced Materials Technologies
·
2025
·
IF 6.2
Junjin Duan,Yanqin Huang,Fuqing Wei,Jiachun Feng
To meet the growing demand for flexible wearable devices in the information era, the development of cost-effective, easy-processable, and mechanically sound flexible luminescent materials is pivotal but remains challenging. Here, a facile one-step melt mixing strategy is reported to prepare the reprocessable polyethylene with high stable fluorescence (f-PE) using low-density polyethylene (LDPE) and high-dosages of benzoyl peroxide (BPO) as raw materials. Typically, after 30 min mixing 50 g LDPE with 1 g BPO in a 110-rpm mixer, the resulting f-PE exhibited high fluorescent brightness and remarkable fluorescent stability. In addition to good fluorescent and mechanical properties, f-PE also demonstrated excellent processability and can be processed using conventional melt processing methods for normal PE. Based on the results, the extended through-space n-π*/π-π* interactions resulting from the high-content BPO-induced extensive grafting of oxygen-containing functional groups on the main chain is proposed, as well as the chain scissions and rearrangement under strong melt shearing, may be main factors to contribute f-PE with luminescent and processable properties. Thanks to advantages such as cost-effective raw materials, and scalable and solvent-free production, the f-PE and its preparation technique show great potential for flexible wearable applications, bringing new opportunities for functionalizing traditional versatile PE.
研究领域:
材料科学
·
高分子化学
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Jiashun Yang,Bo Xian,Haoxiang Li,Liqun Zhang,Dongli Han
There are increasing concerns about the global issues of carbon peak and carbon neutrality . The tire labeling laws about rolling resistance performance requirements have been revised accordingly. Energy-efficient “green tires,” with a lower rolling resistance, are becoming an important development direction for the tire industry. Herein, a method is proposed for preparing a silica/natural rubber (NR) masterbatch using solution compounding. The dispersion of silica in the rubber matrix was improved through the liquid-phase mixing process. Further, the loss factor (tanδ) of the rubber was reduced, ultimately reducing the rolling resistance of the material. Specifically, the modified silica slurry was prepared in cyclohexane with an interfacial modification technology, and the mixing between the silica and rubber molecular chains was completed in the organic phase. Favorable processing properties were confirmed using the Mooney viscosity test. Compared with the in situ modified silica/NR composites made using dry blending, the silica/NR composites made via solution compounding had better filler dispersion, better mechanical properties , lower tanδ and lower rolling resistance. Thus, the preparation of a silica/NR masterbatch using solution compounding provides a new procedure for the preparation of silica/NR compounds with excellent performance for “green tires.”
研究领域:
材料科学
·
轮胎工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Huajie Gao,Yuan Gao,Jianmin Zhang,Jianfeng Wang,Yanyu Yang,Wanjie Wang,Yanxia Cao
In this study, we synthesized ethylene-acrylic acid copolymer/recycled polyvinyl butyral (EAA/RPVB) blends using hexamethylene diisocyanate (HDI) and dicumyl peroxide (DCP) as crosslinking agents via a one-step melt blending method. This approach facilitated the formation of distinct crosslinked structures in both the RPVB and EAA phases. By adjusting the blend ratios, we engineered materials with a pseudo-interpenetrating polymer network (IPN) structure. The resulting EAA/RPVB blends exhibited a broad range of glass transition temperatures and independent crystallization/melting transitions, culminating in a remarkable triple and quadruple shape memory effects. The crosslinking reactions facilitated by HDI and DCP were systematically analyzed through torque rheological measurements, gel content assessments, and spectroscopic techniques. Our results revealed that the reactivity of HDI with the hydroxyl groups of RPVB was notably higher than that of DCP with EAA. Additionally, varying the blend compositions influenced the degree of crosslinking and network morphology, as evidenced by gel content testing, dynamic rheological analyses, and scanning electron microscopy (SEM) observations. These findings suggest that the unique structural characteristics and high crosslinking density of the blends contribute to their enhanced shape memory performance and mechanical properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yuhan Wang,Huihuang Ma,Shuni Ying,Jianfei Gao,Xiaodong Zhou
Starch is considered an ideal alternative to petroleum-based plastics. However, the application of thermoplastic starch (TPS), which produced from cassava starch plasticized with glycerol, is limited by its hydrophilic, poor mechanical properties, and inadequate processability. In this study, dialdehyde starch (DAS) is used as crosslinker to modify TPS/poly(vinyl alcohol) (PVA), and DAS crosslinked cassava starch/PVA blends are fabricated by melt mixing method. Studies on the molecular structure of DAS crosslinked cassava starch/PVA blend indicate that the addition of DAS enhances the intermolecular interactions between cassava starch and PVA, resulting in the formation of a dense internal structure. The plasticizing torque and equilibrium torque of crosslinked cassava starch/PVA blends are increased and the tensile strength reaches 3.60 MPa, an improvement of 186% compared with TPS. Additionally, the water contact angle increases from 87.8° to 119.6° after modification. Compared with other crosslinkers, DAS has obvious advantages, making the DAS crosslinked cassava starch/PVA blend a biodegradable material with excellent properties and promising application prospects.
研究领域:
材料科学
·
高分子科学
·
生物降解材料
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Xin Zheng,Caixia Zhang,Chuntao Luo,Guanghua Tian,Lian Wang,Yongjin Li
The inclusion complex of thermoplastic polyurethane (TPU) and β-cyclodextrins (β-CD) with high TPU contents has been synthesized. The channel structure with large amount of uncovered TPU was confirmed by wide-angle X-ray diffraction (WAXD). High performance poly(oxymethylene) (POM) alloys were fabricated by simply melt mixing neat POM with the synthesized TPU inclusion complex (IC-TPU). The effects of the incorporation of IC-TPU on the structure and properties of POM have been investigated. Scanning electron microscope (SEM) results showed that IC-TPU was dispersed uniformly in POM matrix and there was robust interface between IC-TPU and POM matrix. Tensile test results indicated significant improvement in both strength and ductility of the IC-TPU modified POM as compared with neat POM. Moreover, the incorporation of IC-TPU resulted in the drastically enhanced thermal stability of POM. The initial degradation temperature increased as high as 40 °C with the addition of a small amount of IC-TPU. The investigation indicated that the IC-TPU exhibited a novel structure with a soft shell (uncovered TPU) and a hard core (β-CD covered TPU segments). Such “soft shell–hard core” structure improves not only the elongation at break but also the tensile strength of POM. The superior thermal stability was originated from the synergetic effects of the hydroxyl groups in β-CDs and the amino groups in TPU. The multifunctional effect of the IC-TPU opens a new avenue for the industrial application of POM.
研究领域:
材料科学
·
高分子工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Yongliang Ding,Chengxin Zhang,Bingbing Shi,Yiyun Wang,Pengfei Tang,Cheng Liu,Jingjing Fan,Zhongkai Wang,Feng Jiang
Degradable polymers typically require prolonged exposure to harsh conditions for degradation, but this extended duration and severe treatment often result in incomplete breakdown, leading to the formation of harmful microplastics that pose significant environmental pollution risks. In this work, degradable alternating polyamide hard segments and soft crystallizable segments were combined by amide groups to design thermoplastic bio-based polyesteramide elastomers (PEAEs) with customizable properties and rapid degradability. The hard segment of the polymer features an alternating arrangement of amide and ester bonds. This arrangement facilitates the formation of small molecule monomers when the ester bond is broken, preventing microplastic contamination that may arise from incomplete degradation of the hard segment. Additionally, the inclusion of side groups in the soft segment disrupts the crystallization, enhancing its susceptibility to solvent penetration and thereby accelerating the degradation rate. After step-cyclic tensile tests, additional physical cross-linking points were formed in PEAEs to enhance their mechanical strength and elasticity. Furthermore, PEAEs demonstrated outstanding processing capabilities, including compounding, extrusion, pelletization, and spinning. This innovative approach introduces fresh design concepts for the industrial application of bio-based degradable polymers, playing a pivotal role in advancing resource conservation and environmental protection.
研究领域:
材料科学
·
聚合物化学
·
环境科学
·
生物降解材料
·
可持续工程
✓ 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）