HOLZFORSCHUNG
·
2018
·Vol. 73
·期 5
·469-474
·
IF 2.079
Yaoge Huang,Gaiyun Li,Fuxiang Chu
Poplar wood samples (2×2×2 cm 3 ) were vacuum/pressure impregnated in alcoholic solution with 2-hydroxyethyl methacrylate (HEMA) and 3-(methacryloxy)propyltrimethoxysilane (MAPTES) in a mass ratio of 3/1 in the presence of catalytic amounts of azobisisobutyronitrile (AIBN). Because of their good solubility and permeability, the HEMA/MAPTES precursors evenly penetrate the poplar cell wall. The impregnated samples were heated at 75°C for 8 h, followed by a heating period at 103±2°C for 8 h, in the course of which an in situ polymerization occurred in the cell wall. The modified wood was characterized by Fourier transform infrared (FTIR) and Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, the dimensional stability of the modified wood was measured and found to be considerably improved.
研究领域:
材料科学
·
木材科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Shuyi Xie,Zhenzhen Liu,Aijun Feng,Xiaolong Hao,Rongxian Ou,Lichao Sun,Tao Liu,Qingwen Wang
Fast-growing poplar with the dominant characteristic of short rotation plantation offers a potential solution to the growing market demand for wood. However, its practical applications are limited due to shortcomings such as high flammability and poor dimensional stability. To address these issues, this study introduced a facile impregnation process involving the in-situ polymerization of bio-based furfuryl alcohol (FA) and ammonium phytate (AMP) to enhance the flame retardancy and dimensional stability of poplar. The biomass content was higher than 95% for this impregnation solution. The thermal stability experiments revealed that the residual char mass of AMP/FA-wood at 800°C increased by 305% compared to unmodified poplar. Moreover, the AMP/FA-wood demonstrated superior flame retardancy, achieving UL-94 V-0 rating and a high limiting oxygen index of 36.3%. Additionally, it exhibited decreased heat release and total smoke production of 48.9% and 79.8%, respectively, in comparison to unmodified poplar wood . The impressive flame retardancy of AMP/FA-wood was ascribed to the incorporation of AMP through the nitrogen-phosphorus synergistic intumescent mechanism. Notably, the in-situ polymerization of FA during the modification process, the AMP/FA-wood displayed exceptional dimensional stability which was confirmed by the moisture content , anti-swelling efficiency, and water absorption tests. Hence, AMP/FA-wood with its excellent flame retardancy, thermal stability, and dimensional stability, holds promise as a reliable wood supply for various applications such as furniture, home decor, construction, and building.
研究领域:
林业科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Ling Yuan Liao,Wen Hong Ruan,Ming Qiu Zhang,Li Weihao
The 5th generation mobile communication technology (5G) requires materials with high reliability, high dimensional stabilities, and low dielectric constant (Dk) and low loss factor (Df). However, achieving both high dimensional stabilities and low dielectric is difficult. In this work, we propose a strategy to improve dimensional stabilities of printed circuit board (PCB) substrates without reducing their dielectric properties by introducing crosslinking agents with trifluoromethyl groups and allyl groups to polymers. Polyphenylene oxide (PPO) was selected as the representative research object, and a series of cured PPO-Allyl-F with varying contents of trifluoromethyl and allyl side chains were designed and synthesized. The molecular structures of the thermosetting PPO were characterized using 1H nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy. The isothermal curing kinetics of the thermosetting PPO were monitored with in situ FTIR. The thermal stability, mechanical properties, glass transition temperature (Tg), coefficient of thermal expansion (CTE), and dielectric properties of the cured PPO-Allyl-F materials were investigated in detail. The results show that the obtained thermosetting PPO with improved dimensional stabilities and low dielectrics has great potential for the application in high-frequency electronic circuits. This work provides a new approach for developing high-performance polymers that can address the contradiction between dielectric properties and dimensional stability.
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 POLYMER RESEARCH
·
2024
·Vol. 31
·期 8
·1-13
·
IF 2.6
Wang Y. B.,Deng X. L.,Cao B. Y.,Feng H. P.,Chen J.,Li P. D.,Ren L.,Zhang M. Y.
In this article, a strategy is proposed to prepare highly toughened composites from polypropylene (PP), rice husk charcoal (RHC) and glycidyl methacrylate (GMA)-modified EPDM using melt blending and hot pressing. The structure of GMA-modified EPDM is confirmed by Fourier transform infrared spectroscopy (FTIR). The influences of the amounts of EPDM and GMA-modified EPDM on PP composites are investigated by virtue of mechanical properties testing, dimensional stability analysis, thermogravimetric analysis (TGA), X ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that the incorporation of GMA-modified EPDM significantly improves the toughness of PP composites and compared to PRHC the impact strength of PRKEG10 is up to the value of 537 J/m and increases by 555%, concurrently the tensile strength and modulus exhibit less decrease with the value of 8.22 MPa and 353 MPa, respectively. Shrinkage measurements show the dimensional change rates of length, width, and height decrease from 3.2%, 2.9%, and 3.3% to 1.73%, 1.46%, and 1.93%, respectively, improving the dimensional stability of PP composites. SEM reveals that shear yield and cavitation during the loading process lead to the excellent toughness of PP composites. This strategy provides a novel route to fabricate high ductility rice husk charcoal-based PP composites and expand certain industrial application.
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
Polymers
·
2020
·Vol. 12
·期 7
·1584
·
IF 3.426
Tingsong Liu,Wenhao Zhang,Jie Wang,Yan Zhang,Hui Wang,Fangli Sun,Lili Cai
Bamboo is a natural and renewable building material but its application has been limited due to the low dimensional stability and poor durability against mold. In this study, monomers of hydroxyethyl methacrylate (HEMA) andN-isopropyl acrylamide (NIPAM) were impregnated in bamboo to facilitate the in situ growth of poly-HEMA and NIPAM (PHN) copolymer. Prior to that, the effects of different reaction conditions, including the molar ratio of HEMA to NIPAM and their concentrations, the amount of initiator (ammonium persulfate, APS) and crosslinking agents (N,N′-Methylenebisacrylamide (MBA), and glutaric dialdehyde (GA)) on the swelling capacity of PHN were optimized. The formation of PHN was confirmed by using Fourier transform infrared spectroscopy and thermogravimetric analysis, which shows the characteristics peaks of both HEMA and NIPAM, and increased pyrolysis and glass transition temperatures, respectively. After impregnation of PHN pre-polymerization formulation to bamboo, it was observed that PHN filled most of the pits in the bamboo cell wall and formed a tight network. Moreover, the dimensional stability of PHN treated bamboo was significantly improved with an anti-swelling efficiency of 49.4% and 41.7%, respectively, after wetting–drying and soaking–drying cycles. A mold infection rate of 13.5% was observed in PHN-treated bamboo as compared to a 100% infected control group after a 30-day mold resistance test. Combined results indicate that in situ polymerization of HEMA and NIPAM in bamboo is a promising method to develop exterior used bamboo products with enhanced dimensional stability and mold resistance.
研究领域:
材料科学
·
林学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Yuliang Jiang,Chao Wang,Jiefeng Pan,Arcadio Sotto,Jiangnan Shen
The preparation of quaternary ammonium polysulfone anion exchange membranes (AEMs) with good dimensional stability and alkaline stability is an urgent problem to solve. In response, a series of cross-linked based on polysulfone and 4, 4′-trimethylenedipiperidine (TMDP) as crosslinkers with different degrees AEMs were developed in this work through a simple process. Among the fabricated AEMs, CAPSF-5 exhibits superb alkaline stability in a 1 M KOH aqueous solution at 60 °C for 15 days, whereas the non-crosslinked APSF membrane became tremendously brittle within 24 h and could not be further studied under the same conditions. In addition, even at 60 °C, CAPSF-5 demonstrates a superior dimensional stability compared to the non-crosslinked APSF membrane due to the formation of a dense internal network structure. These observations demonstrate that crosslinked CAPSF membranes can be a viable strategy to improve the deficiency of the polysulfone backbone, especially in terms of alkaline stability.
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
Polymers
·
2023
·Vol. 15
·期 7
·1727
·
IF 5
Qinchen Duan,Xin Zhang,Shuang Lang,Guowei Liu,Hui Wang,Xiaojian Zhou,Guanben Du
Energy storage materials to modulate indoor microclimates are needed to improve energy efficiency and for human comfort. Of these, phase-change material (PCM) is considered a very useful material because of its excellent latent heat energy storage. For application, some synthetic porous materials for supporting PCM are usually not friendly enough for people and housing environments due to their non-degradation characteristics. Hence, to develop an eco-friendly porous material is needed in order to encapsulate PCM composites that are always expected in indoor applications. In this work, heat-treated bamboo bricks were delignified to provide a delignified bamboo (DB) matrix. A phase-change composite was then fabricated by impregnating DB with polyethylene glycol (PEG) polymer. Impregnation was carried out under wet conditions to ensure the regular arrangement of the DB structure so as to achieve dimensional stability. The final DB/PEG composite was investigated for dimensional stability, load rate, latent heat, and phase-change temperature. Results showed that the DB matrix could be easily impregnated with PEG polymer under wet conditions, and the DB/PEG composite was found to have high enthalpy and a large phase-change temperature interval. Moreover, the composite was found to be a good regulator of indoor temperature and a stable dimension with a snow-white appearance. In summary, this DB/PEG composite is an energy storage material with the potential to modulate ambient indoor temperature and reduce building energy consumption.Keywords:delignified bamboo;polyethylene glycol;phase-change temperature;energy storage;dimensional stability
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2017
·
IF 6.035
Chen Xiao Lin,Yi Zhi Zhuo,En Ning Hu,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
Covalent crosslinking is considered to be a promising strategy to balance the dimensional stability and conductivity of anion exchange membranes (AEMs). Nevertheless, crosslinking using diamine crosslinkers would introduce hydrophobic alkyl chains into the ionic domain resulting in a significant decline in hydroxide conductivity and crosslinking via catalyst is discouraged. Herein, we presented a strategy for preparing crosslinked AEMs without using catalyst and the crosslinked moiety is away from the ionic domain. The crosslinking was carried out by converting the trifluorovinyl groups into perfluorocyclobutane groups via thermal treatment. The designed side-chain structure is responsible for the obvious hydrophilic/hydrophobic phase separated morphology and interconnected ion conducting channels, as confirmed by atomic force microscopy , transmission electron microscopy and small angle X-ray scattering. The obtained membrane exhibited high dimensional stability and a highest conductivity of 77.1 mS cm −1 at 80 °C. Furthermore, the crosslinked AEMs also had robust mechanical properties , good thermal stability and reasonable alkaline stability.
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 MEMBRANE SCIENCE
·
2021
·
IF 8.742
Qian Wang,Lei Huang,Jifu Zheng,Qifeng Zhang,Guorui Qin,Shenghai Li,Suobo Zhang
Anion exchange membranes (AEMs) with high anionic conductivity and mechanical robustness are required for alkaline membrane fuel cells (AMFCs) and are significantly influenced by the water uptake (WU) of the membrane. When the swelling ratio (SR) becomes too large, the mechanical integrity of the membrane becomes compromised, which may have catastrophic consequences for the fuel cell. Herein, backbone Poly(arylpiperidinium) (PAP) with no ether bond, rigidity and hydrophobic structure was combined with the hydrophobic guanidinium salt to design and synthesize a series of AEMs containing novel guanidinium salts through a simple and efficient route. The introduction of the guanidinium salt structure with large steric hindrance significantly improved the dimensional stability of the AEMs; the WU of membrane material at 80 °C was under 12%, and the SR was less than 3%. In addition, the AEMs showed excellent thermal stability, with the decomposition temperatures of the guanidinium group and the backbone being 350 °C and 450 °C, respectively.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 4
·738
·
IF 4.967
Wenhao Zhang,Jianchao Zhou,Zhijin Cao,Xinxing Wu,Hui Wang,Shuaibo Han,Yan Zhang,Fangli Sun,Ting Zhang
The extension of wood to a wider field has been restrained significantly due to its dimensional instability that arises from variation in moisture content, which in turn brings about the risk of cracking, warping or distortion. This work proposed a novel strategy to stabilize wood by means of the in situ construction of a thermotropic shape memory polymer (SMP) inside wood. The cross-linked copolymer network (PMP) with good shape memory behavior was first investigated based on the reaction of methyl methacrylate (MMA) and polyethylene glycol diacrylate (PEGDA) in a water/ethanol solution; then, the PMP was constructed inside wood via vacuum-pressure impregnation and in situ polymerization. The weight gain, volume increment and morphology observations clearly revealed that the PMP was mainly present in wood cell lumens, cell walls and pits. The presence of PMP significantly enhanced the dimensional stability of and reduced the cracks in wood. The desirable shape recovery abilities of PMP under heating-cooling cycles were considered to be the main reasons for wood dimensional stabilization, because it could counteract the internal stress or retard the shrinkage of cell walls once water was evaporated from the wood. This study provided a novel and reliable approach for wood modification.Keywords:shape memory polymer;wood;in situ construction;dimension stability;anti-cracking
研究领域:
材料科学
·
林业工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Wenbin Dong,Liujun Pei,Jun Zhu,Shibo Cui,Feichao Zhu,Chenglong Wang,Jiping Wang
In the realm of environmental protection and sustainable development, polylactic acid (PLA) materials have garnered significant attention due to their biodegradability. Moreover, PLA is more widely used in the clothing and home textile industries. However, the application of PLA in the textile industry is constrained by hydrolysis issues during conventional aqueous dyeing processes. This paper investigates a waterless dyeing technique utilizing linear silicone (LS) as a nonaqueous dyeing medium. Because PLA fibers are dyed in a nonaqueous environment, the breaking strength of PLA fabrics in the LS waterless dyeing system increased by 4% to 10%, and the breaking elongation improved by 7% to 20% at dyeing temperatures of 110 and 120 °C. However, it showed a reduction of 23.4% at 120 °C in water-bathed dyeing. The LS waterless dyeing system facilitates high-temperature dyeing of PLA fibers, ensuring that the fibers remain intact at temperatures below 140 °C. In contrast, when subjected to traditional water bath dyeing at 120 °C, the fibers exhibit significant breakage. The hydrolysis concerns are mitigated in the LS waterless dyeing bath, resulting in enhanced thermal stability and mechanical properties compared to that in fibers dyed in a conventional water-bathed dyeing system. At equivalent temperatures, the K/S value of dyed PLA fabric can be improved when a small dosage of acetic acid is employed in a waterless dyeing bath, while color fastness to washing, rubbing, and light remain uninfluenced. The selected dyeing medium can be recycled and reused, which not only significantly improves the resource utilization efficiency of the dyeing process but also effectively reduces the generation and emission of waste. This study provides a promising approach for waterless dyeing of PLA fiber, facilitating their practical application and marking an important milestone toward sustainability in the textile industry.
研究领域:
纺织科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2017
·
IF 5.527
Mali Zhou,Xu Chen,Jiefeng Pan,Shanshan Yang,Bo Han,Lixin Xue,Jiangnan Shen,Congjie Gao,Bart Van der Bruggen
To improve the dimensional stability of electrodialysis membranes, a series of crosslinked sulphonated polysulfone cation exchange membranes with different degrees of sulfonation were prepared by a simple and low energy consumption method, namely UV-crosslinking. The crosslinking reaction was performed by UV irradiation and using 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (TPO) as photoinitiator and trimethylolpropane tri-acrylate (TMPTA) as crosslinker . The scanning electron microscopy (SEM) and atomic force microscopy (AFM) results showed that crosslinking leads to a denser and smoother surface. Compared with the swelling and water uptake results of pristine membranes , the crosslinked membranes exhibited an enhanced dimensional stability, especially at higher temperature (40–70 °C). The thermogravimetric analysis and measurement of mechanical properties indicated that the crosslinked membrane has better mechanical and thermal properties. The electrochemical properties were analyzed, and the membrane after crosslinking showed a better ion permselectivity . When applied in electrodialysis and compared to the commercial membrane with a NaCl removal ratio of 75.6%, the crosslinked membranes showed a more efficient performance (NaCl removal ratio = 89.1% for SPSU-60). These improvements showed that the crosslinked membranes can be promising candidates for high-temperature and industrial application.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）