JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 3
·e53318
·
IF 3.057
Aoqi Li,Yingqing Ye,Peixin Gong,Bo Xiao,Bo Jiang
Compared with traditional conjugates 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS), 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) is an emerging biological coupling reagent and has been used in the amidation of hyaluronic acid. In this paper, DMTMM was used to achieve the amidation of chitosan (CS) with glucuronic acid (GA) in an aqueous medium to generate a GA-CS derivative. The grafting efficacy was preliminarily compared with the EDC/NHS-mediated reaction. As a result, the substitution degree of 17.6% for DMTMM-mediated grafting and 13.1% for EDC/NHS chemistry indicated that DMTMM-mediated synthesis of GA-CS appeared to be more efficient. The reaction kinetics experiments showed that GA-CS derivative with a degree of substitution up to about 26.1% was obtained using equal molar ratios of DMTMM and GA exceeding CS at room temperature. These results indicate that employing DMTMM as a coupling agent is a feasible and promising strategy for the amidation modification of chitosan.
研究领域:
生物化学
·
材料科学
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DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 8
·1861
·
IF 5
Jihang Hu,Xiaoqing Wang
As the only renewable resource among the four basic materials (steel, cement, plastic, wood), wood itself and wood products have a “low carbon” value and play an important role in storing carbon. The moisture absorption and expansion properties of wood limit its application scope and shorten its service life. To enhance the mechanical and physical properties of fast-growing poplars, an eco-friendly modification procedure has been used. This was accomplished by the in situ modification of wood cell walls by vacuum pressure impregnation with a reaction of water-soluble 2-hydroxyethyl methacrylate (HEMA) and N,N’-methylenebis(acrylamide) (MBA). The anti-swelling efficiency of HEMA/MBA-treated wood was improved (up to 61.13%), whereas HEMA/MBA-treated wood presented a lower weight-gain rate (WG) and water-absorption rate (WAR). It was observed that the modulus of elasticity, hardness, density, and other properties of modified wood had improved significantly, as indicated by XRD analysis. Modifiers diffuse primarily within cell walls and cell interstices of wood, causing crosslinks between the modifiers and the cell walls, reducing its hydroxyl content and blocking the channels for water movement, thereby enhancing its physical properties. This result can be obtained by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX), Nitrogen adsorption test imaging ATR-FTIR (Attenuated total reflection-Fourier-Transform Infrared) Spectroscopy, and nuclear magnetic resonance (NMR) and Nitrogen adsorption test. Overall, this straightforward, high-performance modification method is crucial for maximizing wood’s efficiency and the sustainable development of human society.Keywords:wood modification;reaction mechanism;cell walls;grafting;properties
研究领域:
林业科学
·
材料科学
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DOI
PubMed
高影响因子
MATERIALS LETTERS
·
2022
·
IF 3.574
Hongming Tang,Linyao Zhou,Xinchao Bian,Tianchang Wang,Lidong Feng,Bao Zhang,Yanlong Liu,Xuesi Chen
Grafting reaction between poly (lactic acid) (PLA) and cardanol was initiated by dicumyl peroxide at different compositions, and the mechanical, thermal properties were characterized. In absence of dicumyl peroxide (DCP), the PLA/cardanol blends showed a typical plastic behavior with increasing cardanol content, i.e. decrement of tensile strength, accompanied by increment of elongation at break, while the notched Izod impact strength kept low level until the cardanol content reached 20 wt%. When DCP was introduced into the blends, only 15 wt% cardanol content was needed to improve the notched Izod impact strength significantly. According to the thermal behavior testing results, the grafting of cardanol onto PLA chains might take responsibility for the further improvement of impact strength with less cardanol content.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Chunyang Li,Duo Ji,Yuxin Wan,Xu Yang,Manzhi Shao,Hong Zhao,Jiansheng Sun
Surface discharge on the EPDM/XLPE interface is threatening the safe operation of power cable system and limiting the further improvement of its voltage level. To improve the electrical strength of EPDM/XLPE interface, the surface of EPDM was modified by grafting of voltage stabilizer 4-allyloxy-2-hydroxybenzophenone (AOHBP) based on liquid-phase impregnation and subsequent free radical grafting reaction thermally initiated by DCP. EPDM samples were modified by mixed reagents of DCP and AOHBP with different mass ratios of 1:2, 1:3 and 1:4, respectively. The SEM observation and XRD analysis results indicate that the crystals of AOHBP with a uniform distribution are covered on the surface of EPDM during the sample preparation process and then dissolved after extraction by acetone. The FTIR and ATR results show that the AOHBP molecules are successfully grafted onto the surface of EPDM samples, but there remain a lot of ungrafted reagent molecules on the surface of EPDM before solvent extraction. The grafting rate of AOHBP increases with the proportion of DCP in the mixed reagents. As for the unextracted modified EPDM samples, both the AC and DC breakdown voltage of the EPDM/XLPE interface are increased compared with pure EPDM, and further increased after the ungrafted molecules are extracted because the effect of voltage stabilizer on scavenging high-energy electrons is more efficiently utilized at a smoother interface. The interface breakdown voltage of the sample modified with 1:2 mass ratio of DCP/AOHBP mixed solution is the highest because of its highest grafting rate of voltage stabilizer. This work has proposed a new technical path to improve the electrical aging resistance of polymer insulating surface.
研究领域:
高分子材料科学
·
电气工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Zijun Zhang,Xinyue Yao,Yan Xu,Haining Na,Chao Fang,Zhu Jin
The synthesis of monomers with two epoxy structures (EIA) was successfully achieved by adopting holo-biobased feedstocks and in situ solvolysis reaction. The molecular structure of EIA was subjected to characterization through the use of infrared spectroscopy (IR), mass spectrometry (MS), and nuclear magnetic resonance hydrogen spectroscopy ( 1 H NMR). The EIA was employed as the epoxy monomers for the synthesis of the grafted compatibilizer, resulting in the successful preparation of a fully bio-based and high epoxy value grafted compatibilizer (PLA-g-EIA (PLE)). The effects of varying proportions of the monomer (EIA) and Bis(tert-butylperoxy-1-methylethyl)-benzene (BIBP) on the dynamic grafting reaction were investigated systematically using IR, 1 H NMR, melt flow index (MFR), and differential scanning calorimetry (DSC). Furthermore, the compatible effects of PLE on the mechanical performances, rheological properties, and microstructure of bamboo powder (BP) enhanced PLA composites were also investigated. Furthermore, a series of comparisons were conducted between PLE and a homemade PLG under identical conditions. The grafting degree (GD) of PLE reached 1.28 % under identical conditions (monomer mass addition of 3 %, monomer: initiator mass ratio of 20:3), whereas the GD of homemade PLA-g-GMA (PLG) was only 0.82 %. In comparison to PLG with varying contents, the prepared PLE markedly augmented the interfacial adhesion between two phases, thereby promoting an enhancement of impact, tensile, and flexural strength. Furthermore, the presence of PLE (5 wt%) enhanced the impact strength by up to 37 %, tensile strength by up to 3.03 MPa, and flexural strength by up to 6.16 MPa of PLA/BP composites compared to the absence of the compatibilizers. Meanwhile, PLE (5 wt%) was 1.68, 2.16, and 2.02 times more effective than PLG in enhancing the notch impact, tensile, and bending strength of composites, respectively.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Dongming Qi,Chenghai Liu,Zhijie Chen,Hangnan Chen,Chujuan Huang,Zhihai Cao
A formation mechanism of guava-like polymer/SiO 2 nanocomposite particles (NCPs) in in situ emulsion (co) polymerization systems based on the enhanced homogenous nucleation was proposed in the present paper. The reactive 3-(trimethoxysilyl) propyl methacrylate modified SiO 2 nanoparticles (NPs) were chemically linked to form a large amount of SiO 2 clusters at the beginning of polymerization. The formation of the SiO 2 clusters driven by highly efficient grafting reaction of monomers to SiO 2 NPs could be regarded as an enhanced homogenous nucleation process. The SiO 2 clusters functioned as the main polymerization loci to form guava-like polymer/SiO 2 NCPs in the following polymerization process. The morphological evolution of the polymer/SiO 2 NCPs, and the role of the grafting reaction and nucleation pattern in the formation of the guava-like polymer/SiO 2 NCPs were systematically investigated.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 17
·5911
·
IF 3.4
Juan Wang,Zhikai Dong,Jingwen Chen,Shuangjun Chen
UV debonding acrylate adhesive (UDAA) plays a crucial role in the semiconductor industry, where its excellent adhesion is required to ensure the stability of silicon wafers and leave no residue on the surface after UV irradiation. The necessary UV debonding is achieved through the formation of rigid networks by the reactions of all the vinyl groups in the system. Acrylate copolymers with vinyl groups are typically obtained by the grafting reaction of isocyanate with a side-chain hydroxyl comonomer. However, these grafting reactions easily fail due to early cross-link formation. In this study, we illustrate a straightforward method for preparing UDAA by conducting a postgrafting reaction after one-step mixing of isocyanate functional monomer (IPDI-H) and hydroxyl acrylate copolymers (BA-H), thereby skipping the abovementioned vinyl grafting process. The chemical structures of the synthesized IPDI-H and BA-H were confirmed using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) analysis. Gel permeation chromatography (GPC) was employed to determine their molecular weights, while differential scanning calorimetry (DSC) was used to determine their glass transition temperatures. The postgrafting reactions successfully introduced vinyl groups onto the polyacrylate copolymer chains, resulting in high bonding strength during use and a significant decrease in peeling strength after UV irradiation. Rheological methods, including the three-interval thixotropy test (3ITT) and tack test modes, were employed to characterize a series of acrylate UV debonding adhesives. The recovery percentage of the storage modulus in the 3ITT mode indicated that a 0.6 wt% isocyanate curing agent made the UV debonding adhesives resistant to deformation. From the maximum normal force in the tack test mode, it was found that UDAA with 10 wt% PETA monomer and 30 wt% C5 tackifying resin exhibited excellent combined adhesion and debonding properties, which were further confirmed by peel strength tests. Microscope images of the wafer surfaces after removing the adhesive tapes demonstrated the excellent UV debonding properties achieved after 40 s of UV irradiation through the postgrafting reaction. The prepared UDAA has excellent properties; the peel strength can reach 15 N/25 mm before UV irradiation and can be reduced to 0.5 N/25 mm after ultraviolet irradiation. This research establishes a comprehensive method for understanding and applying UDAA in various applications.Keywords:UV debonding adhesives;acrylates;postgrafting;cross-linking;rheology
研究领域:
材料科学
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高分子化学
·
半导体制造
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产品关联
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2021
·Vol. 79
·期 11
·9543-9562
·
IF 2.87
Gong Jiaying,Qiang Zhe,Ren Jie
A one-step reactive extrusion process has been demonstrated to toughen the poly(lactic acid) (PLA) blend without sacrificing its mechanical strength and degradability. Specifically, poly(lactic acid) (PLA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and the peroxide initiator were first introduced into the mixer and then heated at the elevated temperatures for triggering the grafting reaction during the extrusion. During this process, the thermal decomposition of PHBV results in the unsaturated bonds that can directly grafted onto the PLA backbones by free radical reactions. From this study, we found that PLA/PHBV blend with a mass ratio of 80/20 (PLA/PHBV) and 0.3 wt% 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (DBPH) is an optimized condition, leading to an improved elongation at break of 15.95%, which is 3.1 times of the PLA and 1.5 times of the PLA/PHBV blend without the initiator, while tensile strength exhibited very limited decreased compared to PLA. Overall, this work presents an environmentally friendly and industrial feasible approach to prepare bio-based toughened PLA for improving the elongation at break, while retaining the tensile strength and degradability.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2022
·Vol. 300
·期 9
·1087-1099
·
IF 2.434
Peña Jhair Andres,Du Xin Jing,Xing Jin Feng
Hybrid nanomaterials were synthesized via grafting poly(N-isopropylacrylamide) (PNIPAM) over silica nanoparticles in a one-pot reaction using the internal and external surface of the nanoparticles as a microreactor system. Silica nanoparticle properties were tuned through templating and pore-swelling agents which allows obtaining spherical and elongated morphologies. Polymerization reactions were carried out at 80 °C for 4 h, using two initiator systems and N,N′-methylenebisacrylamide as a cross-linker. The structures obtained were studied by SEM and TEM micrographs, and the presence of polymer was confirmed through 1 HNMR and FTIR analysis. The thermoresponsive behavior was analyzed by DLS and DSC. It was found that the silica core structure and the initiator solubility affect considerably the aggregation and the size distribution of the grafted nanoparticles. Therefore, it is observed that different parameters can be used to drive grafting reactions without any previous functionalization step on the core surface, showing a straightforward method for their production.
研究领域:
材料科学
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化学工程
·
纳米技术
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产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2022
·Vol. 80
·期 11
·12447-12462
·
IF 2.843
Liu Fangjun,Shen Chenxi,Jiang XueLiang,You Feng,Yao Chu,Shangguan Yecheng
Ordinary polypropylene homopolymer (PP) has low melt strength and mechanical properties, which greatly restricts its application in foam molding. In this work, high melt strength polypropylene (HMSPP) is successfully fabricated by melting grafting technique using dicumyl peroxide as an initiator and trimethylolpropane triacrylate (TMPTA) as a grafting monomer. The effects of different reaction temperatures and formulas on modified PP are investigated. The results show that the introduction of TMPTA will reduce the melt flow rate, and improve the grafting ratio, torque, melt strength (MS), mechanical properties, thermal stability, and crystallization rate of polypropylene. It is found that HMSPP prepared at 170 °C 1.2 Phr TMPTA has the best comprehensive properties, with MS increased by 3.8 times, elongation at break increased by 120%, flexural modulus increased by 25%, impact strength increased by 33.3%, and thermal decomposition temperature increased by 52.6 °C. In addition, PP/HMSPP is extruded and foamed, and the results show that the foaming performance of HMSPP is better than that of PP. In general, the introduction of TMPTA improves the mechanical properties, melt strength, foaming property, and thermal stability of PP. Graphical abstract
研究领域:
材料科学
·
聚合物工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 7
·
IF 1.866
Hua Mei,Ran Wang,Wentan Ren,Yong Zhang
A novel organic–inorganic hybrid of epoxycyclohexyl polyhedral oligomeric silsesquioxane (e-POSS)–grafted carboxylic methoxypolyethylene glycols (mPEG-COOH), that is, a POSS-mPEG graftomer, was synthesized. The grafting reaction of e-POSS and mPEG-COOH was characterized by Fourier transform infrared (FTIR) and 1 H-NMR spectroscopy. Then the graftomer was used to develop new composite solid polymer electrolyte (SPE) films with a carboxylated nitrile rubber–epoxidized natural rubber (XNBR-ENR) self-crosslinked blend system as a dual-phase polymer matrix. The self-crosslinked reaction of the XNBR-ENR matrix was investigated using ATR-FTIR. The morphology of the SPE films and the distribution of lithium salt were investigated using field emission scanning electron microscopy and X-ray diffraction, and the result illustrated that the addition of POSS-mPEG could promote and accelerate the dissociation of LiClO 4 . The best effect within the range of this study was achieved when 25 phr POSS-mPEG was involved. The differential scanning calorimetry analysis proved that the glass-transition temperature of the composite SPE films was reduced with the increase of POSS-mPEG. The ionic conductivity of the composite SPE films was investigated by electrochemical impedance spectroscopy. The highest ionic conductivity in this study of 2.57 × 10 −5 S cm −1 was obtained with 25 phr POSS-mPEG loading. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44460.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 10
·1-10
·
IF 2.6
Yang Lei,Gao Lijing,Wei Ruiping,Xia Rongying,Wang Ziqi,Liu Huijun,Yao Mingzhu,Ma Guanghui,Xiao Guomin
Ethylene-vinyl acetate (EVA)grafted 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (V4) polymer EVA-g-V4 was prepared by free-radical solution grafting reaction. The results of the purified grafted products by FT-IR, 1 H NMR, XRD, TG and DSC show that V4 has been successfully grafted onto the main chain of EVA. The effects of the dosage of V4 and BPO on grafting ratio were studied. When the dosage of V4 was 6.0 wt%, and the dosage of BPO was 0.8 wt%, the grafting ratio was up to 1.4%. The cross-linking behaviour was verified by SEM. Compared with pure EVA film, the peel strength, mechanical properties, volume resistivity and hydrophobicity of EVA-g-V4 film all improved with increasing grafting ratio. This work provides a new option in the field of photovolatic encapsulation materials.
研究领域:
材料科学
·
能源技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）