JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 46
·e53170
·
IF 3.057
Yinhan Xu,Jun Wang,Zhu Luo,Jianjun Li,Bai Xue,Xingjiang Chen,Xiaolong Li,Le Yang,Changkai Linghu,Yao Tao
The recycling of petroleum-based polymers such as polypropylene (PP) and polyethylene (PE) is an effective means of reducing environmental pollution. However, the incompatible PP and PE blended waste is difficult to separate accurately, which reduces the quality of the recycled material. In this paper, the trifunctional acrylate monomer (trimethylolpropane triacrylate), peroxide (2,5-dimethyl-92,5-di[tert-butylperoxy] hexane) and free radical activity modifier (zinc dimethyldithiocarbamate) were applied to in situ generate the copolymer of isotactic polypropylene and high-density polyethylene (iPP-co-HDPE) with a long-chain co-branched structure via a melt blending method. The co-crystallization of the branched copolymer chain segments with the chemical identical homopolymers vastly improved the compatibility of iPP and HDPE components. This in situ co-branching compatibility strategy resulted in a significant improvement in the mechanical properties of PE and PP mixed wastes. The temperature gradient extraction method was used to separate the co-branching modified iPP/HDPE blends. The results confirm that the separated iPP-co-HDPE components have a highly co-branched structure. The significant improvement in compatibility resulted in a large increase in elongation at break and impact strength of the iPP/HDPE blends, which provides an economic and effective method for the recycling of mixed PE and PP wastes.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wei Feng,Mo Zheng,Jin Bai,Xianxian Zhang,Chuang Wu,Zhenxing Guo,Lingxue Kong,Zongqing Bai,Wen Li
Understanding the effects of co-pyrolysis synergies between low-rank coal and high-density polyethylene (HDPE) on the carbon structure evolution in char and the relationship between char structure and chemical bonds evolution is very needed. A combination of ReaxFF MD and experimental approaches provides an opportunity for fully understanding the dynamic profiles of char structures and coking trends during co-pyrolysis process of coal and HDPE. In this work, consistent conclusions were obtained from fixed-bed experiments and ReaxFF MD simulations in product distribution during both individual coal pyrolysis and co-pyrolysis at different temperatures. The ReaxFF MD simulation results reveal that adding HDPE partially inhibited the coking process of coal char. The RDF results indicated higher order degree and aromaticity exist in coal/HDPE(7:3)-Char when compared to those in coal-Char, which agrees well with the findings from XRD and FTIR approaches. By analyzing the evolution of C=C, C=O, C-O, C( sp 2 )-C( sp 3 ), C( sp 3 )-C( sp 3 ) and C( sp 2 )-H bonds in C 40 + fragments during secondary simulations of co-pyrolytic char, it was observed that the structural order and aromaticity of co-pyrolytic char increase with temperature, and the oxygen-containing bonds are the initial recombination sites for char formation. These findings provide rich theoretical information to complement the understanding of char structure in co-fed systems and the interaction between coal and HDPE blend.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2023
·Vol. 29
·期 6
·991-1001
·
IF 2.7
Hua Zhou,Liangdong Ye,Dongming Chen,Ziwei Li,Shanrong Li,Dacheng Li,Zhiyi Huang,Zhouqiao Wei,Shaorong Lu
Graphite is a thermally conductive filler. However, when dispersed into high density poly(ethylene) (HDPE) resin, graphite particles tend to agglomerate and requires a compatibilizer to achieve desired thermal/physical properties. In this study, oleic acid (OA), a bio-based additive and polyethylene-polyamines (PEPA) were used to synthesize a new compatibilizer, PEPA-g-OA, containing numerous NR 2 groups. The experimental results showed that PEPA-g-OA can significantly improve the compatibility between graphite particles and the HDPE matrix due to uniform dispersion of graphite in the HDPE matrix. When the graphite content was 25 wt%, the thermal conductivity of the composite recorded 1.2 W m −1 K −1 (three times that of neat HDPE) and the volume resistivity was 1.8 × 10 9 Ω cm, indicating excellent electrical insulation. Compared to the composites with no graphite content, the properties of the composites with 25 wt% graphite content exhibited narrower melting and crystallization peaks, more stable mechanical properties, and higher ultraviolet aging resistance. Synthesized new bio-based compatibilizer and thermally conductive and electrically insulating composites developed in this study can be useful in different industrial fields for the preparation of the next generation composites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 131
·期 3
·
IF 1.395
Peng Fei,Benhua Fei,Yan Yu,Hanguo Xiong,Jun Tan
In this study, bamboo fiber/high-density polyethylene (HDPE) composites were prepared, and the effects of nano-TiO 2 on their thermal properties and crystallization behavior were investigated via thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results show that the addition of nano-TiO 2 improved the thermal stability and had a dual function in the crystallization behavior of the composites. On one hand, it functioned as a nucleating agent. The addition of 2 wt % nano-TiO 2 promoted the crystallization, which caused the increase of the crystallization rate and crystallinity degree, as well as the micronization of the crystalline grain. On the other hand, intermolecular hydrogen bonds and covalent bonds were formed between nano-TiO 2 and the polymer matrix, which hindered the crystallization of the composites. When the content of nano-TiO 2 was continually increased, the inhibitory effect of the crystallization was gradually enhanced, which resulted in a decrease in the crystallization rate and crystallinity degree of the composites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39846.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 5
·509-517
·
IF 2.804
Chen Yu,Yao Jian,Xu Ming-Ke,Jiang Zhi-Guo,Zhang Hao-Bin
Electrically conductive and flame-retardant maleic anhydride grafted high-density polyethylene (MA-HDPE) nanocomposites with satisfactory mechanical properties are fabricated by melt compounding MA-HDPE with polyethyleneimine (PEI)-modified reduced graphene oxide (PEI@RGO) as the conductive nanofiller and brominated polystyrene (BPS) as the flame retardant. The modification with PEI significantly improves the interfacial compatibility and dispersion of the RGO sheets in the MA-HDPE matrix, leading to electrically conductive nanocomposites with enhanced mechanical properties. Furthermore, the addition of 25 wt% of BPS makes the nanocomposite flame-retardant with a UL-94 V-0 rating. Thus, the multifunctional RGO/MA-HDPE nanocomposites with good electrical, flameretardant, and mechanical properties would have potential applications in construction and pipeline fields.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Jing Gu,Honggang Fan,Yazhuo Wang,Yuyuan Zhang,Haoran Yuan,Yong Chen
The thermal weight-loss characteristics and product distribution of the co-pyrolysis between xylan from corn cob (XC) and high-density polyethylene (HP) were investigated by thermogravimetry coupled with fourier transform infrared spectroscopy and mass spectrometry (TG-FTIR-MS) and pyrolysis gas chromatography/mass spectroscopy (Py-GC/MS). Moreover, the synergistic effects in the co-pyrolysis process were explored. The co-pyrolysis of XC and HP occurs in two stages. The first stage (220–350 °C) was the decomposition of XC, and the second stage (440–525 °C) was mainly attributed to the decomposition of HP. Co-pyrolysis caused the blends to decompose more easily. The synergistic effect was confirmed during the co-pyrolysis process. The co-pyrolysis process promoted the release of hydrocarbons (CH 4 , C 2 H 2 , C 2 H 6 , C 3 H 6 , and C 3 H 8 ) and aldehyde derivatives (CH 3 CHO and CHO + ) and decreased the production of H 2 and H 2 O. Moreover, co-pyrolysis suppressed the generation of CO 2 only when the content of HP was 75%. The Py-GC/MS results showed that the yield of oxygen-containing compounds decreased, and the yield of alkenes and alkanes increased. The increase in alkenes was greatest when the ratio of XC to HP was 1:3. This phenomenon could be attributed to the release of hydrogen radicals from mono-molecular and bi-molecular dehydrogenation reactions during the decomposition of HP. Thus, HP could be a hydrogen donor, providing hydrogen for xylan-derived oxygenates, which served as acceptors. A reaction mechanism for the co-pyrolysis of XC and HP was also proposed.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Bingtao Wang,Yanqun Pan,Liping Zhao,Juan Li,Zhenghong Guo
To investigate the effect of fullerene (C 60 ) and its iron compound (C 60 -Fe) on the thermal and thermo-oxidative degradation mechanism of high-density polyethylene (HDPE), the Kissinger method, Flynn-Wall-Ozawa method and Coats-Redfern methods are used. The data of thermal and thermo-oxidative degradation are achieved through the thermogravimetric (TG) analysis, and the trapping free-radical ability and the dispersion of C 60 or C 60 -Fe in matrix are characterized by the electron spin resonance (ESR) and transmission electron microscopy (TEM). C 60 and C 60 -Fe improve effectively the thermal and thermo-oxidative stability of HDPE. In N 2 , C 60 and C 60 -Fe do not change the degradation mechanism of HDPE, and the degradation rate is determined by the random generation and growth of free-radicals. In air, C 60 changes the reaction order ( n ) of HDPE at the oxidation stage and the degradation mechanism at the random fracture. C 60 -Fe changes the thermo-oxidative mechanism of HDPE due to the formation of cross-linked network.
研究领域:
材料科学
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Xianyue Liang,Zhixiang Huang,Yonghui Zhou,Chuanshuang Hu,Dengyun Tu,Litao Guan
The preparation of wood-plastic composites (WPCs) with high filling fibers and excellent physical properties remained a great challenge. This study used Camellia oleifera shell (COS, agroforestry product waste) as raw material, and prepared 60 wt% COS/high-density polyethylene (HDPE) WPCs using profile extrusion method through pretreating fibers including hot water, hot steam, alkali, acid, extraction, and fine fiber screening. After pretreatments, the relative contents of cellulose and lignin increased, the relative contents of hemicellulose and extract decreased significantly, and the length-diameter ratio was improved. The flexural strength, tensile strength and impact strength of hot water and steam heat treated composites reached 31.4, 17.1 MPa and 6.9 kJ/m 2 , 31.8, 16.8 MPa and 6.7 kJ/m 2 , respectively. Compared with untreated 28.8, 14.7 MPa and 5.5 kJ/m 2 , the advantages were more obvious. Alkali treatment and acid treatment improved the thermal stability and residue rate of the material. Extraction treatment and alkali treatment significantly reduced the processing torque force, which was conducive to processing, while acid treatment was the opposite. The highest water absorption and thickness expansion rate were 13.75% and 3.60% respectively at 7 days after alkali treatment, which were considerably higher than 5.60% and 0.78% without treatment, while other pretreatments improved the dimensional stability of the material. Highlights High filling Camellia oleifera shell waste/HDPE composites were prepared. Physical and chemical pretreatments improved interfacial adhesion of the composites. Heat treatments significantly improved mechanical performance of the composites.
研究领域:
材料科学
·
林业工程
✓ 已验证
产品关联
DOI
高影响因子
FIRE AND MATERIALS
·
2020
·Vol. 44
·期 4
·506-515
·
IF 1.925
Zhenghong Guo,Yanqun Pan,Ruifeng Guo,Zhengping Fang
Summary Fullerene decorated by iron compound (C 60 -Fe) is fabricated via solution reaction and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), wide-angle X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Upon incorporating C 60 -Fe into high-density polyethylene (HDPE) matrix by melt blending, the thermal and thermo-oxidative stability of HDPE are considerably increased, the oxidative induction time (OIT) is dramatically extend. When the concentration of C 60 -Fe reached 5 wt%, the onset degradation temperature in air increased from 352°C to 422°C, and the OIT dramatically delayed from 4.5 to 47.8 minutes. Moreover, from microscale combustion calorimetry (MCC), C 60 -Fe can reduce the peak heat release rate ( PHRR ), heat release capacity ( HRC ), and total heat release ( THR ) values of the composites, all of which are very important parameters for evaluating the fire retardancy of a polymeric material.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yinhan Xu,Xiaolong Li,Xingyu Wang,Zhu Luo,Jingshun Liao,Yao Tao,Mengxia Xu
An industrialized polymer molding technology that combines water-soluble etching and surface chemical reactions was proposed for preparing a superhydrophobic high-density polyethylene (H@G-E/HDPE) sheet. HDPE sheets were etched with a saturated aqueous solution of NaF to create a rough surface, after which glycidyl methacrylate (GMA) was introduced onto the HDPE surface to create a large number of reactive sites on the inert surface of HDPE, enabling further grafting of a low-surface-energy hydroxyl-terminated fluorosilicone oil (HTFO) onto the HDPE surface. The H@G-E/HDPE sheet exhibited high hydrophobicity , with a water contact angle (WCA) of 158 ± 1° and sliding hysteresis angle (SHA) of 8 ± 1°. The sheet also exhibited good durability, with a WCA greater than 150° after 240 h of strong stirring in water or abrasion with sandpaper for 120 rubs. The H@G-E/HDPE sheet exhibited chemical resistance and maintained super-hydrophobicity even after 24 h of immersion in a strong acid/alkali solution. Furthermore, the super-hydrophobicity of the as-obtained H@G-E/HDPE sheet was maintained upon impact with water droplets at 0.77 m/s, along with low ice adhesion at 11.64 ± 1.74 KPa, a significantly longer icing delay time, and self-cleaning properties. The developed superhydrophobic H@G-E/HDPE sheet featuring low-cost and efficient fabrication has promising applications in many industries, such as pipelines, membranes, packaging, and electronic equipment.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Kezhen Qian,Wenmin Tian,Lijie Yin,Zixu Yang,Feixiang Tian,Dezhen Chen
The nature of Zn species and their roles in catalytic cracking of high-density polyethylene (HDPE) thermal decomposing vapor over Zn-promoted HZSM-5 (Zn/Z5) for aromatics were investigated. The Zn/Z5 zeolites were prepared using ion exchange and impregnation methods followed by H 2 reduction. Results indicated that hydrogen reduction of the Zn/Z5 significantly improved the aromatic yield. [ZnOH] + and bridged Zn 2+ species were critical species promoting BTX formation, with the former demonstrating higher activity. Besides, the synergistic effect between the Zn species and Brønsted acid sites on HZSM-5 boosts the aromatic yield. Incorporation of Zn was also found to promote long-chain scission. Among all the Zn/Z5, hydrogen reduced 2 wt% Zn/Z5 (SAR=25) is most effective in producing BTX, with a maximum yield of BTX (48%) and BTX selectivity (93%); hydrogen reduced 2 wt% Zn/Z5 (SAR=50) produced the highest yield of total aromatics (53%).
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Kezhen Qian,Wenmin Tian,Zixu Yang,Jing Xu,Huihua Pan,Lijie Yin,Dezhen Chen
The catalytic upcycling of end-of-life polyethylene by using hierarchical zeolites has garnered attention. Fine-tuning these zeolites’ micromesoporous structure and acidity is crucial for process efficiency, which requires a comprehensive understanding of their impact on polyethylene cracking. The impact of the mesoporosity and acidity of aggregated hierarchical HZSM-5 zeolites on high-density polyethylene (HDPE) vapor cracking was studied. The results indicated that the hierarchical structure enhanced accessibility to internal acid sites, facilitating monomolecular cracking and aromatization. Intercrystalline mesopores additionally heightened the alkylated aromatic yields. The Si/Al ratio shows a positive correlation toward the C5+ aliphatic hydrocarbon cracking, which boosts the formation of C2–C4 olefins and BTEX (benzene, toluene, ethylbenzene, and xylene). However, the presence of mesopores also yielded more heavy aromatics, thus increasing the risk of coking. The role of acid sites spatial distribution was investigated by poisoning the acid sites in micropores via pre-coking. The results indicated that the cracking of HDPE vapor occurred on the external acid of the zeolite, followed by the subsequent C5+ aliphatic hydrocarbon cracking on the mesopore and micropore to form aromatics and C1–C4 products. The formation of BTEX mainly occurred in the micropore, while the heavier aromatics and other alkylated benzenes were formed in the mesopore. The results of this study highlighted the importance of a proper hierarchical structure and acid site distribution in zeolites for effective and stable polyolefin cracking.
研究领域:
化学工程
·
催化材料
✓ 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）