INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Li Zhao,Shulai Lu,Ming Chen,Yuchao Wang,Shicheng Zhao
Polymer agglomeration has a good application prospect in enlarging the particle size of polybutadiene latex (PBL), which has attracted considerable attention in the field of agglomeration. However, the agglomeration process of PBL under different agglomeration conditions has not been studied. In this study, a coaxial cylindrical viscometer was used to perform agglomeration experiments. The different stages of PBL agglomeration can be determined by observing the viscosity changes, because the particle size of nanoparticles in the emulsion is an important factor affecting its viscosity. In this communication, the effects of the content of agglomerating agent, agglomeration temperature, and shear rate on the agglomeration process and particle size of PBL were studied. It was found that with the increase of the content of agglomerating agent, the time required to reach the adsorption saturation and complete the entire agglomeration of PBL decreased. When the content of the agglomerating agent was 4%, the agglomerated PBL showed a bimodal distribution. Then, the mean particle size of agglomerated PBL decreased with the increase of the content of the agglomerating agent. However, when the content of the agglomerating agent exceeded 20%, the mean particle size of agglomerated PBL did not change and remained stable at about 255 nm. Temperature has no obvious effect on the agglomeration process of PBL with 4% agglomerating agent content but can significantly reduce the agglomeration time with 16% and 24% agglomerating agent content. The effect of the shear rate on the agglomeration process of PBL with 4% agglomerating agent content is not obvious. With the increase of the shear rate, the time required for PBL to complete the agglomeration decreased for the systems with 12% and 24% agglomerating agents. In addition, the particle size of agglomerated PBL can be significantly reduced with the increase of shear rate when the content of the agglomerating agent is 12%. This study not only provides a new perspective for the study of the agglomeration process of PBL but also helps to precisely control the agglomeration conditions of PBL and improve the agglomeration efficiency.
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
MACROMOLECULAR RAPID COMMUNICATIONS
·
2024
·Vol. 45
·期 19
·2400259
·
IF 4.2
Zhihao Niu,Yimin Wang,Xin Wang,Dexian Yin,Tao Shou,Pengfei Cao,Xiuying Zhao,Shikai Hu,Liqun Zhang
The thermodynamic incompatibility between the soft and hard segments of thermoplastic polyurethane (TPU) results in a microphase-separated behavior and excellent mechanical properties. However, the effect of the chain extender on the degree of microphase separation (DMS) and the resultant mechanical properties of TPU have not been well studied because of the complex interactions between the soft and hard segments. Herein, hydroxyl-terminated polybutadiene-based TPUs(HTPB-TPUs) without hydrogen bonding between the soft and hard segments are synthesized using hydroxyl-terminated polybutadiene, toluene diisocyanate, and four different chain extenders, and the effect of the chain extender structure on DMS is analyzed experimentally using a combination of analytical techniques. Furthermore, the solubility parameters of the soft and hard segments, glass transition temperatures, and hydrogen-bond density of the HTPB-TPUs, are computed using all-atom molecular dynamics simulations. The results clearly reveal that the chain extender significantly affects the DMS and thus the mechanical properties of HTPB-TPUs. This study paves the way for studying the relationship between the structure and properties of TPU.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Yu Zhang,Jian Zheng,Xiao Zhang,Yongqiang Du,Ke Li,Yahao Liu,Guibo Yu,Yunfei Jia,Shijun Song
Polyurethane (PU), used as the adhesive of composite solid propellants, is prone to damage. Nowadays, self-healing capability has been regarded as the attractive solution. However, self-healing PU usually reveals unsatisfactory mechanical performances failing to meet the requirements of composite solid propellants. In this work, a feasible method was developed to achieve the adhesive with remarkable mechanical and self-healing characteristics by introducing dual dynamic bonds into hydroxyl-terminated polybutadiene (HTPB)-based PU. It exhibits a substantial efficiency of self-healing of about 93% for 2 h at 60 °C. Meanwhile, the self-healing efficiency is 74% when repairing for 6 h at 25 °C. Impressively, this material demonstrates significant mechanical properties, even over a wide temperature range. Its elongation at break at room temperature is up to 2706.8%. It exhibits 1447.9% and 1458.9% elongation at break at 70 °C and − 40 °C, respectively, significantly higher than that of HTPB. The present research represents an essential and achievable approach for the preparation of the high-performance self-healing composites propellant adhesive with outstanding high and low temperature mechanical properties.
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
CARBON
·
2018
·
IF 7.082
Suhang Chen,Yue Tang,Hongsheng Yu,Xinyan Guan,Luigi T. DeLuca,Wei Zhang,Ruiqi Shen,Yinghua Ye
Hydroxyl-terminated polybutadiene (HTPB) is extensively used in propulsion; however, it's trapped in low regression rate, partly related to poor thermal transfer from combustion. Carbon nanotubes (CNT) act as an energy transfer media, potentially accelerating the heat transfer and combustion performance of HTPB. Herein, multiwall CNT (MWCNT)/HTPB composites were prepared by dispersing MWCNT and surfactant into HTPB and toluene solvent through ball milling . Low MWCNT content (≤1%) promoted combustion, and excess MWCNT (≥2%) depressed, despite MWCNT shifting the HTPB-O 2 reaction to higher temperatures. (0.5%, 1%, 2% and 3%) MWCNT/HTPB composites reinforced the instantaneous regression rate by 11.2%, 31.6%, −21.3%, and −39.7% at Gox = 365 kg/m 2 ·s; by 27.0%, 25.0%, −26.4%, and −36.6% at Gox = 150 kg/m 2 ·s; while strengthened the average regression rate by 0.9%, 8.5%, −17.4%, and −36.7% at Gox = 365 kg/m 2 ·s; and by 5.4%, 8.9%, −8.3%, −22.6% at Gox = 100 kg/m 2 ·s. Specifically, the optimal MWCNT level was 1%, as demonstrated by the optimized reinforced thermal conductivity and slightly reduced energy release, since excessive MWCNT (>2%) hinders combustion through heat dissipation, high viscosity of the melting layer, low energy release and an attached carbon layer on the burning surface blocking the energy transfer.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 39
·21926-21932
·
IF 2.936
Jie Liu,Xiaodong Fan,Xin Min,Xiuzhong Zhu,Na Zhao,Zichao Wang
This work explores the synthesis of polybutadiene (PB) with high cis-1,4 unit content and narrow molecular weight distribution using a neodymium-based complex, consisting of neodymium(III) trifluoromethane sulfonate (Nd(CF3SO3)3) and coordinated with tris(2-ethylhexyl)phosphate (TOP). The complex's composition and structure are characterized by elemental analysis, XPS and FT-IR. Combined with Al(i-Bu)3, a binary catalyst is obtained and then applied to initiate the polymerization of butadiene. Results indicate that the catalyst system displays a high catalyst activity and the product polymer (PB) features a high cis-1,4 content (98.8%) and a remarkably narrow molecular weight distribution (Mw/Mn = 1.32). Compared with PB initiated by the current well-studied catalyst Nd(CF3SO3)3*3TBP/Al(i-Bu)3, the Nd(CF3SO3)3*3TOP allows significantly narrowing the molecular weight distribution of the PB, because the Nd(CF3SO3)3*3TOP is more easily dissolved in hexane. Therefore, butadiene was polymerized in a homogenous system and each monomer's polymerization was initiated in the single molecular state.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Qingqin Ye,Peitao Zheng,Xiaohu Ao,Dahua Yao,Zhiwen Lei,Yonghong Deng,Chaoyang Wang
Using conductive binders, instead of the traditional binders and conductive additives, is an effective way to increase the specific capacity and long cycle life of the silicon (Si) anode. However, the rigid conductive binders of Si anodes tend to form cracks during the repetitive huge volume changes of Si. Here, a novel n-type conductive binder, multi-block polymer of poly(1-pyrenemethyl methacrylate) and polybutadiene (PPy- b -PB) was designed. The polybutadiene (PB) rubber was incorporated into the conductive binder by combining condensation and reversible addition-fragmentation chain transfer polymerization. With high initial coulombic efficiency of 77.9%, the PPy- b -PB/Si anode possesses high reversible capacity (2274 mAh g −1 ) and capacity retention (87.1%) at the rate of 0.2 C (0.84 A g −1 ) after 200 cycles. The superior cyclic performance of the PPy- b -PB can be ascribed to the PB rubber, which enhanced the reversible deformation ability, flexibility, and adhesion length scale of the binder, without with a negligible change of the charge-transfer resistance for the anode. The original structure and the preparation method of the multi-block conductive binder provide a new way to manufacture multifunctional binders.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Yuhang Du,Yuanshan Cheng,Mingyao Zhang,Baijun Liu
Styrene–acrylonitrile copolymer (SAN) is widely used in various industries due to its excellent transparency, rigidity, and chemical resistance, but its brittle properties limit its utilization and development in niche areas. To improve the brittle properties of SAN resins for more applications, different PBA latexes were synthesized in this study by semicontinuous emulsion polymerization, and two key factors affecting the toughening effect of the resins, particle size and gel content of the poly butyl acrylate (PBA) rubber particles, were effectively and easily controlled. It was found that the crosslinker content and monomer dropping time could control the gel content of PBA latex, while the particle size of the latex was affected by the emulsifier distribution ratio and monomer dropping time. In addition, acrylate styrene acrylonitrile (ASA) resins were constructed by blending PBA-g-SAN graft copolymers with SAN resins, and impact strength tests were conducted to demonstrate the toughening effect on SAN resins. The experimental results show that the gel content can be as low as 73.03%, the particle size varies from 200 nm to 530 nm, and the maximum impact strength of ASA resin reaches 6.17 kJ/m 2 .
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2024
·
IF 3.9
Li Zhao,Shulai Lu,Ming Chen,Yuchao Wang,Shicheng Zhao
Polymer agglomeration is a useful way to enlarge the particle size of polybutadiene latex (PBL). However, the agglomeration process is very complex and is affected by many factors. Therefore, it is difficult to predict the mean particle size and distribution of agglomerated PBL. This study proposed a novel simulation method based on the artificial neural network (ANN) model. Firstly, the influence of agglomeration conditions on the particle size of agglomerated PBL were investigated, including the particle size of pre-agglomerate PBL, the amount, the α-methacrylic acid (α-MAA) content, the solid content and the particle size of agglomerating agent. It is found that these factors have a close nonlinear relationship with the mean particle size and polydispersion index (PDI) of agglomerated PBL. Then, a model containing 236 data points was built using ANN including these properties as input with mean particle size and PDI of agglomerated PBL as output. The coefficient of determination ( R 2 ) values predicted by ANN for training, validation, test and total data are 0.9879, 0.9964, 0.9930, and 0.9902, respectively. It indicates that there is a good agreement between experimental data and predicted results by ANN. This study demonstrates that a simple machine learning method has good performance in predicting the particle size of agglomerated PBL, which further improves the development efficiency of PBL polymer agglomeration. Graphical
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
FUSION ENGINEERING AND DESIGN
·
2021
·
IF 1.453
Jie Du,Xinxin Tan,Liping Wang,Cheng Qin,Xiaoqiong Chen,Zhigang Wu,Biao Guo,Wenhua Luo
Deuterated-tritiated polymers are a type of promising target materials for inertial confinement fusion (ICF). The preparation of a deuterated-tritiated polymer was performed from a deuterated polybutadiene under tritium through solid state catalytic tritiation with 5 wt% Pd/BaSO 4 as a catalyst. After reaction, the gas mixture in the vessel and the raw T 2 /Ar mixture in the flask were analyzed with a gas chromatography, a quadrupole mass spectrometer and a high resolution gas analysis mass spectrometer. The 2 H-NMR and 3 H-NMR spectra were employed to characterize the deuterated-tritiated polymer. Both isotopic exchange and addition during the reaction were confirmed and the tritium ratio of the deuterated-tritiated polymer was determined to be 26.5 %.The solid state tritiation free of solvents can avoid the generation of high radioactive liquids.
研究领域:
材料科学
·
核物理学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Gang Huang,Xi-ao Yan,Rongrui Shi,Jing Sun,Qiang Fang
With the rapid development of high speed and high frequency communication, organic low dielectric (low- k ) materials with both ultra-low dielectric constant ( D k ) and ultra-low dielectric loss ( D f ) are urgently required to ensure signal transmission speed and reliability. 1,2-polybutadiene ( 1,2-PB ) is renowned for its excellent dielectric properties, making it used in high-frequency printed circuit boards (PCBs). However, its poor thermal stability and mechanical properties hinder its application which requires persistent stability. To address this issue, a series of thermal-crosslinkable benzocyclobutene (BCB)-modified PBs were synthesized through a hydrosilylation reaction. These cured PBs exhibited significantly enhanced thermal stability with the glass transition temperature ( T g ) exceeding 400 °C. In particular, they displayed ultra-low D k (2.32–2.41) and ultra-low D f (<0.001). It was found that the properties of cured PBs were related to BCB loadings. Among the cured polymers, PB- g -B 30 demonstrated the optimal dielectric properties with a D k of 2.34 and a D f of 3.6 × 10 −4 . Subsequently, a PB- g -B 30 /glass fiber laminate was fabricated, exhibiting superior dielectric and comprehensive properties when compared to commercial low- k laminates. This study provides a facile method to develop PBs with ultra-low D k and D f and enhanced thermal stability. The outstanding comprehensive properties indicate their potential as low- k materials in high-frequency communication applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Coatings Technology and Research
·
2018
·Vol. 15
·期 6
·1413-1422
·
IF 1.619
Yi Hongling,Wei Ting,Lin Heng,Zhou Junjie
The effects of hydroxyl-terminated polybutadiene (HTPB) number average molecular weight ( \( \overline{{\boldsymbol{M\fancyscript{n}}}} \) ) and preparation temperature on montmorillonite (MMT) intercalation/exfoliation behavior were investigated. X-ray diffraction and Fourier transform infrared spectroscopy results indicated that 40 to 80°C were the preferred temperatures to obtain nanostructured HTPB/MMT. The higher \( \overline{{\boldsymbol{M\fancyscript{n}}}} \) (> 2800) of HTPB led to a more exfoliated nanostructure than lower \( \overline{{\boldsymbol{M\fancyscript{n}}}} \) as proven by transmission electron microscopy. The tensile strength, tensile modulus, and elongation at break of nanostructured HTPB/MMT/EP ternary composites were higher than those of the HTPB/EP binary blend, which was due to the HTPB/MMT hybrid structure. The effect of increasing molecular weight on impact strength in the ternary system was less than that in the binary system. The HTPB/MMT/epoxy hybrid composites with low concentration could improve the impact strength, which was due to the superposition effect of organic/inorganic nanostructures. In hybrid HTPB/MMT/epoxy composite system, the toughening was attributed to the slow crack growth and fast crack growth, and the dissipated energy of pulling or debonding nanoclay out from the matrix also contributed.
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
RSC Advances
·
2015
·Vol. 5
·期 35
·27421-27430
·
IF 3.84
Yingying Ren,Qing Gao,Cheng Zhou,Zhiyong Wei,Yu Zhang,Yang Li
A series of linear-comb highly branched poly(ε-caprolactone) (LC-PCL) with well-defined structure, high molecular weight and narrow polydispersity was synthesized using hydroxylated polybutadiene as macroinitiator and 1,5,7-triazabicyclo-[4.4.0]dec-5-ene (TBD) as catalyst at room temperature. First, the macroinitiator, functionalized hydroxylated polybutadiene was prepared by anionic polymerization of butadiene, epoxidation and ring-opening reaction. Then the hydroxyl groups in the hydroxylated polybutadiene initiated the ring-opening polymerization of ε-caprolactones in the presence of TBD. In an effort to optimize the reaction system, the effects of different reaction factors on the ring-opening polymerization were investigated. The simplicity of the reaction conditions, the ready availability of the catalyst, and the exquisite control over the polymerization were also demonstrated. The arm number, side chain length, and molecular weight of branched LC-PCL were regulated by adjusting the number of hydroxyl groups on macroinitiator and monomer/hydroxyl group feed ratios. Physical properties (thermal property, crystal structure and spherulitic morphology) of the obtained polymers were analyzed by DSC, TGA, WAXD and POM. The results showed that the branched PCL crystallize in the ordinary crystal form similar to linear PCL, and the crystallization and melting behaviors are strongly dependent on the side PCL chain length.
研究领域:
高分子化学
·
材料科学
✓ 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）