POLYMER ENGINEERING AND SCIENCE
·
2014
·Vol. 55
·期 1
·8-13
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IF 1.441
Tian Lan,Wenjie Yang,Juan Peng,Mingke Li,Yinghan Wang
The article aimed to decrease the memory effect of polymer dispersed liquid crystals (PDLCs) films, reversible additional-fragmental chain transfer (RAFT) polymerization was used to synthesize RAFT-polystyrene (RAFT-PS), which was a kind of RAFT macroinitiators and used to prepare PDLCs via photo polymerization induced phase separation (PIPS). Different RAFT agents were used to synthesize RAFT-PS. The effect of photoinitiator concentration on the memory effect of these PDLCs was investigated, and the effect of structures of RAFT macroinitiators on the memory effect of the PDLCs was also discussed. The results showed that PDLC films with higher photoinitiator concentration and polymer matrix which had two rigid chains in two ends showed lower memory effect, which could be reduced from 10.9% to 2.5% in this experiment. POLYM. ENG. SCI., 55:8–13, 2015. © 2014 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·Vol. 143
·期 3
·1391-1395
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IF 2.072
Kemin Wang,Yuhui Lu,Penghui Chen,Jingsong Shi,Hongning Wang,Qiang Yu
Benzophenone (BP) is a common initiator which is often used in the UV-curing production and related fields. However, the shortcomings such as toxicity, odor, and migration always limit the development of the traditional BP photoinitiator . Polymeric benzophenone photoinitiator (PEG-BP) was synthesized basing on polyethylene glycol (PEG), succinic anhydride , 4-hydroxybenzophenone and epichlorohydrin . The structure of PEG-BP was characterized by IR and 1 H NMR. The radiation absorption of PEG-BP was detected by UV spectrophotometer with the maximum absorption wavelength at 283 nm in acetonitrile solvent, undergone significant redshift corresponding to small molecule photoinitiator BP, thus enhanced the photosensitive efficiency of UV-curing system in the long wavelength region. Besides, PEG-BP has better water solubility than BP, thus could be used in both oil and aqueous solution. The obvious advantage of this initiator was the elimination of amine based hydrogen donors and to provide alternative hydrogen donors with easily availability and non-toxicity. The effects of molecular weights of PEG-BP, photoinitiator concentration, UV-radiation intensity and different monomers on photopolymerization kinetics were investigated in detail. The synthesized polymeric photoinitiators are attractive to be used as type II photoinitiators.
研究领域:
高分子化学
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光化学
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材料科学
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功能材料
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辐射固化技术
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DOI
高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 4
·2433-2443
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IF 5.044
Zhou Yihang,Wang Kai,Hu Dongbo
A previous study on consolidation of waterlogged archaeological wood (WAW) via surface initiated ARGET ATRP of the cell walls has shown its potential of maintaining the dimensional stability. But the defects lie in the unsuitable initiator immobilization methods and polymerization conditions, which impedes its application. Therefore, we are proposing a novel functionalization method for initiator immobilization in water or water/ethanol solution and an improved thermo-initiated ARGET ATRP system. First, mercaptoethylamine (MEA) was used to functionalize WAW with amino groups in water under circumneutral conditions. Then, quinone-based initiators reacted with those amino groups realizing its immobilization. Finally, by using less active reductants such as ascorbic acid 2-glucoside and glucose, monomer, catalyst, and reductant were able to permeate into the WAW samples at room temperature and polymerization was initiated by heating to 60 °C (for ascorbic acid 2-glucoside) or 80 °C (for glucose). Both satisfying uniformity and dimensional stability (77.0–85.1% ASE) can be achieved through the described approach. Moreover, the described functionalization methods may also provide reference for WAW consolidation material designs and applications in other lignocellulosic materials in the future.
研究领域:
考古学
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高分子科学
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文物保护科学
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DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2018
·Vol. 58
·期 12
·2185-2191
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IF 1.551
Xuying Nan,Yi Huang,Jianzhong Shao,Huiqiong Yan,Mingshu Wu,Yuhua Yao
Silk peptide used as a co-initiator in type 2 photo-initiator has not been known. In this study, the photoinitiation system is composed of the sensitizer, the synergist and silk peptide with low molecular weight (<3,500), which is used to initiate photopolymerization of common monomer. The same photopolymerization was performed to evaluate the co-initiating ability of four essential amino acids of silk peptide, and of four pentapeptides synthesized using them as substrates, respectively. It was suggested that the glycine residue and alanine residue on silk peptide might be mainly responsible for the co-initiating role. And the co-initiating function might be ascribed to the electron/hydrogen donation of silk peptide. Silk peptide combined with the sensitizer and iodonium salt could also efficiently initiate photo-curing of hydrogel precursors. And due to excellent water solubility of silk peptide, the water absorption of the formed hydrogel could be further improved. These studies will open an opportunity for the application of silk peptide as a biocompatible co-initiator. POLYM. ENG. SCI., 58:2185–2191, 2018. © 2018 Society of Plastics Engineers
研究领域:
材料科学
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生物医学
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高分子化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Zhiquan Li,Xiucheng Zou,Guigang Zhu,Xiaoya Liu,Ren Liu
Developing efficient unimolecular visible light-emitting diode (LED) light photoinitiators (PIs) with photobleaching capability, which are essential for various biomedical applications and photopolymerization of thick materials, remains a great challenge. Herein, we demonstrate the synthesis of a series of novel PIs, containing coumarin moieties as chromophores and oxime ester groups as initiation functionalities and explore their structure–activity relationship. The investigated oxime esters can effectively induce acrylates and thiol-based click photopolymerization under 450 nm visible LED light irradiation. The initiator O-3 exhibited excellent photobleaching capability and enabled photopolymerization of thick materials (∼4.8 mm). The efficient unimolecular photobleachable initiators show great potential in dental materials and 3D printings.
研究领域:
材料科学
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化学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
Polymers
·
2016
·Vol. 8
·期 2
·55
·
IF 2.944
Baijun Liu,Yajun Wang,Mingyao Zhang,Huixuan Zhang
Particle coagulation is a facile approach to produce large-scale polymer latex particles. This approach has been widely used in academic and industrial research owing to its higher polymerization rate and one-step polymerization process. Our work was motivated to control the extent (or time) of particle coagulation. Depending on reaction parameters, particle coagulation is also able to produce narrowly dispersed latex particles. In this study, a series of experiments were performed to investigate the role of the initiator system in determining particle coagulation and particle size distribution. Under the optimal initiation conditions, such as cationic initiator systems or higher reaction temperature, the time of particle coagulation would be advanced to particle nucleation period, leading to the narrowly dispersed polymer latex particles. By using a combination of the Smoluchowski equation and the electrostatic stability theory, the relationship between the particle size distribution and particle coagulation was established: the earlier the particle coagulation, the narrower the particle size distribution, while the larger the extent of particle coagulation, the larger the average particle size. Combined with the results of previous studies, a systematic method controlling the particle size distribution in the presence of particle coagulation was developed.Keywords:emulsion polymerization;particle size distribution;coagulation;initiator
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
POLYMERS & POLYMER COMPOSITES
·
2022
·
IF 1.841
Ming Gong,Daijun Zhang,Jiayang Zhang,Jun Li,Xiangbao Chen
Vinyl polymerization is an important path for in-situ polymerization of thermoplastic resins. BPO (Benzoyl peroxide) and DMT (dimethyl-p-toluidine) were chosen to initiate the radical polymerization of MMA (methyl methacrylate) in this work. Optimization of initiator concentration was studied through reaction rate of polymerization progress and properties of PMMA (polymethyl methacrylate). At first, the catalytic of DMT in MMA polymerization was studied through polymerization experiments and rheological experiments. Results showed that DMT could catalyze more than one molecular BPO in the whole reaction period. It can catalyze the decomposition of BPO after being connected to PMMA chains. Second, the BPO: DMT ratio was set to 2:1 to study the ideal content by comparing the mechanical properties of PMMA. Results showed that with the increase of initiator contents, Tg, molecular weight, and residual monomer were all declining. Meanwhile, the mechanical properties of PMMA matrix first increased and then decreased. This phenomenon was analyzed by 1H-NMR and SEM. And the optimal BPO-DMT concentration was 1.0 mol%–0.5 mol%.
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 36
·
IF 1.866
Yangzhi Xie,He Huang
On the basis of 2-hydroxyl-2-methyl-1-phenylpropanone (HMPP) and poly(ethylene glycol) (PEG), we prepared amphiphilic macrophotoinitiators (HMPP–PEG–HMPP) by first reacting HMPP with isophorone diisocyanate and subsequently reacting it with PEGs with different chain lengths. Fourier transform infrared spectroscopy, high-performance liquid chromatography, and 1 H-NMR were used to confirm the structure of the amphiphilic macrophotoinitiators. Ultraviolet (UV) absorption spectra showed that the amphiphilic macrophotoinitiators had maximum absorption wavelengths that were similar to those of the low-molecular-weight photoinitiator HMPP. The photolysis rate of the amphiphilic macrophotoinitiators was slightly lower than that of HMPP, but the migration rate of the amphiphilic macrophotoinitiators from a UV-cured matrix was much lower compared to that of HMPP. Because of their amphiphilic nature, these macrophotoinitiators may play roles as both photoinitiators and emulsifiers, and they have been applied to the solution polymerization of water-soluble monomer acrylamide in water and the emulsion polymerization of methyl methacrylate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43910.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY
·
2025
·Vol. 38
·期 1
·11-19
·
IF 0.7
Mengting Zhao,Mengyun Wang,Li Jin,Boyang Cheng,Tianjiao Hou,Xuan Shen
The development of high-performance UV-LED excited photoinitiators (PIs) is one of the current research hot spots in the field of photopolymerization. Thioxanthone (TX) derivatives have good UV-visible absorption ability under UV excitation. In this article, four novel thioxanthone derivatives were designed and synthesized as one-component polymerizable photoinitiators, and their structures were confirmed by FT-IR and 1H NMR. Their photophysical/photochemical, kinetic and migration stability were investigated experimentally by UV-vis spectrophotometer and Fourier transform infrared spectrometer. The photolysis and photoinitiation mechanisms of four initiators were elucidated. Comparison of the results for the TX system showed that these TX derivatives are highly efficient one-component polymerizable PIs with high migration stability, which has the potential to be used in UV curing systems, especially for food packaging and biomedical applications.
研究领域:
高分子化学
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光化学
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材料科学
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生物医学工程
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食品包装技术
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产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2012
·Vol. 62
·期 10
·1457-1464
·
IF 1.902
Youmei Bao,Jing He,Yuesheng Li
Hyperbranched polyesters with thioether linkages were facilely prepared from methyl 10-undecenoate, a castor oil-derived renewable chemical. The monomer was obtained in excellent yield through thiol–ene click chemistry in the presence of catalytic amounts of photoinitiator under UV irradiation. Subsequent bulk polycondensation via a transesterification process catalyzed by Ti(OBu) 4 , Sb 2 O 3 or Zn(OAc) 2 gave hyperbranched polyesters with high molecular weights and unusual crystalline properties. The degree of branching in the range 0.45 − 0.54 calculated from quantitative 13 C NMR spectroscopy and low inherent viscosities of 0.16 − 0.25 dL g −1 strongly confirmed the hyperbranched structures of the resultant polymers. © 2012 Society of Chemical Industry
研究领域:
材料化学
·
可再生资源化学
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Shunsheng Wei,Jingrun Yuan,Gaoling Yang,Haizheng Zhong,Yuping Dong,Jianbing Shi
Precise pixel control of quantum dots (QDs) offers unparalleled opportunities for various display applications, such as the OLED and Micro-LED. However, precise selective patterning of QDs is still a challenge due to the lack of a design methodology. Therefore, the aim of this study was thus to develop a photoinitiator-grafted oligomer for “on demand” control of active free radicals to improve the line edge roughness in QD patterning. This photosensitive oligomer was constructed by grafting the photosensitive benzophenone structure onto a phenolic resin oligomer, thus resulting in the confinement of active free radicals and highly selective photolithography. As a proof of concept, we have demonstrated high-quality QD patterns with high resolution and low edge roughness by using direct in situ photolithography. This work opens an avenue for the precise design and synthesis of QD photoresists, improving the precision of QD patterning for display applications.
研究领域:
材料科学
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显示技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2013
·
IF 2.596
De zhan Ye,Li Jiang,Chao Ma,Ming-hua Zhang,Xi Zhang
The influence of lignin species on the grafting mechanism of lignosulfonate (from eucalyptus and pine, recorded as HLS and SLS, respectively) with acrylic acid (AA) was investigated. The graft polymers were confirmed by the absorption of carbonyl groups in the FTIR spectra. The decreasing phenolic group's content (Ph-OH) is not only due to its participation as grafting site but also to the negative effect of initiator. In the initial period (0–60 min), HLS and SLS both accelerate the polymerization of AA. Additionally, Ph-OH group's content is proportional to product yield ( Y %), monomer conversion ( C %) and grafting efficiency (GE%), strongly indicating that it acts as active center. Nevertheless, compared with HLS, Y % and C % in SLS grafting system are lower though it has higher Ph-OH group's content, which is due to the quinonoid structure formed by the self-conjugated of phenoxy radical in Guaiacyl unit. Finally, the lignosulfonate grafting mechanism was proposed.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）