PROGRESS IN ORGANIC COATINGS
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2016
·
IF 2.632
Guangxue Chen,Xiaoyuan Guan,Ruixin Xu,Junfei Tian,Minghui He,Wei Shen,Jianwen Yang
In this paper, UV-curable castor oil-based polyfunctional polyurethane acrylate (COME-PUA) was synthesized via photo-click chemistry and isocyanate polyurethane reaction. Facile and highly efficient side-chain functionalization of castor oil (CO) was first achieved via thiol-ene photo-click chemistry with β-mercaptoethanol (ME). 1 H NMR result indicated that almost 100% conversion of double-bond in CO was observed within 10 min, and the average hydroxyl functionality of the obtained polyol COME was about 6. Next, COME was modified by isocyanate polyurethane reaction with hydroxypropyl acrylate (HPA), isophorone diisocyanate (IPDI) and PEG-200 as the chain extender in order to prepare the resin COME-PUA. Results of both 1 H NMR and FTIR revealed that the targeted COME and COME-PUA were successfully synthesized. Furthermore, UV-curing kinetic of COME-PUA was revealed by real-time FTIR, showing a higher UV-curing rate than the common CO-PUA. Finally, some physical properties of curing films were studied.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
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2020
·
IF 2.671
Yongxia Ren,Yunsheng Dong,Ruoning Yang,Youwei Yao
Ultraviolet (UV)/thermal dual-curable polyurethane acrylate (PUA) mixtures were prepared using a PUA oligomer , tripropylene glycol diacrylate (TPGDA), benzoyl peroxide (BPO), 2,4,6-trimethylbenzoyldiphenyl phosphine oxide (TPO), and cobalt isooctanoate. For purposes of comparison, a UV-curable PUA mixture was prepared by mixing the PUA oligomer, TPGDA, and TPO. When placed under a UV lamp (400 W, 50 mW/cm 2 ), the surface drying time of each curable mixture was approximately 2 s. The content of volatiles during UV curing (the intensity of the lamp was 100 mW/cm 2 ) was less than 0.3 wt%, and the content of potential volatiles (the test condition was heating at 110 °C for 1 h after UV curing) was below 1.0 wt%. Compared with the UV-cured sample, the UV/thermal dual-cured sample containing cobalt isooctanoate had more favorable properties, that is: (1) better acid and alkali resistance; and (2) better thermal stability and higher gel content. The temperature at 5 wt% weight loss ( T 5wt.% ) and the gel fraction of the UV-cured sample (the curing condition was 1 min of UV irradiation) were 269.4 °C and 94.6%, respectively. The T 5wt.% and the gel fraction of the UV/thermal dual-cured sample (cured at 100 °C for 10 min after 1 min of UV irradiation) were 318.2 °C and 99.8%, respectively. BPO and cobalt isooctanoate had little effect on the surface drying rate of the curable mixtures, and the performance of the cured samples was improved by thermal treatment following irradiation with UV. Considering the dyeing effect of BPO, this system provides a more practical approach to the complete curing of colored UV-curable resins.
研究领域:
材料科学
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聚合物化学
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DOI
高影响因子
Chemistry-An Asian Journal
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2022
·Vol. 18
·期 1
·e202201097
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IF 4.839
Shuangyan Hu,Lijun Liu,Heng Li,David Pahovnik,Nikos Hadjichristidis,Xuechang Zhou,Junpeng Zhao
Graphical The reactions between poly( ϵ -caprolactone) and epoxides catalyzed by strong phosphazene bases result in ester-ether copolymers with high randomness owing to concurrent ring opening and transesterification. Enzymatic degradability of the copolymers can be bidirectionally regulated by the pendant group derived from the substituent of epoxide. A series of ester-ether copolymers were obtained via the reaction between α , ω -dihydroxyl poly( ϵ -caprolactone) (PCL) and ethylene oxide (EO) or monosubstituted epoxides catalyzed by strong phosphazene bases. The two types of monomeric units were distributed in highly random manners due to the concurrence of epoxide ring-opening and fast transesterification reactions. The substituent of epoxide showed an interesting bidirectional effect on the enzymatic degradability of the copolymer. Compared with PCL, copolymers derived from EO exhibited enhanced hydrophilicity and decreased crystallinity which then resulted in higher degradability. For the copolymers derived from propylene oxide and 1,2-butylene oxide, the hydrophobic alkyl pendant groups also allowed lower crystallinity of the copolymers thus higher degradation rates. However, further enlarging the pendant groups by using styrene oxide or 2-ethylhexyl glycidyl ether caused a decrease in the degradation rate, which might be ascribed to the higher bulkiness hindering the contact of ester groups with lipase.
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
PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
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2022
·Vol. 33
·期 7
·2265-2275
·
IF 3.348
Xuan Fei,Yingkang Zhu,Jinggang Wang,Zhen Jia,Xiaoqing Liu
To enhance the crystallization of poly(butylene 2,5-furandicarboxylate) (PBF) thus substitute its petroleum-based analogue poly(butylene terephthalate) (PBT), a series of high molecular weight poly(butylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate) (PBCF) copolyesters with low contents (0–19 mol%) of 1,4-butanediol (BDO) are synthesized from 2,5-furandicarboxylic acid (FDCA), 1,4-cyclohexanedimethylene (CHDM) and BDO. Their chemical structures and compositions are confirmed by nuclear magnetic resonance ( 1 H NMR and 13 C NMR). Their number average molecular weights are from 20,500 to 36,100 g/mol with the polydispersity index ( Ð ) of 1.67–1.99. The thermal stability and crystallization behaviors are investigated by thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC). Results show that PBCFs demonstrate comparable crystallization rate to PBT as the crystallization half time is from 18 to 29 s and the melting enthalpy is 34.1–41.4 J/g as well as the higher melting temperature of 238–263°C than 225°C for PBT. In addition, PBCFs exhibit excellent mechanical properties of tensile modulus between 1220 and 1510 MPa. These investigations suggest that a moderate amount CF unit can improve the melting temperature and enhance the originally weak crystallizability of furan-based polyesters. Generally, PBCFs can be the engineering plastic with satisfied thermal and mechanical performance.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Zhang Kai,Xin Jiaying,Lu Xuechun
This study established a Candida rugosa lipase (CRL) system to catalyze triolein and ethyl ferulate interesterification. The products were identified, and the binding mode between the substrates and CRL was predicted through molecular docking. Three methods for preparing CRL-AuNPs were proposed and characterized. It was found that the addition of 40 mL of 15 nm gold nanoparticles increased the CRL activity from 3.05 U/mg to 4.75 U/mg, but the hybridization efficiency was only 32.7 %. By using 4 mL of 0.1 mg/mL chloroauric acid, the hybridization efficiency was improved to 50.7 %, but the enzyme activity was sharply decreased. However, when the molar ratio of Mb to HAuCl 4 was 0.2, the hybridization efficiency increased to 71.8 %, and the CRL activity was also enhanced to 5.98 U/mg. Under optimal conditions, the enzyme activity of CRL-AuNPs③ was maintained at 95 % after 6 repetitions and 85.6 % after 30 days at room temperature.
研究领域:
生物化学
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酶工程
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纳米生物学
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产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
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2024
·
IF 6.5
Yanmei Zhu,Chao Zhou,Li Liu,Guangfeng Wu
Trimethylolpropane (TMP) as a cross-linker and KH-602, a siloxane coupling agent, were precisely grafted onto the branched chains of PPCD waterborne polyurethanes using molecular structure design. A series of waterborne polyurethanes (WPUs) were synthesized by selecting polycarbon dioxide-based polyol (PPCD) and isocyanate (IPDI) as soft and hard segments. The effects of changes in the content of TMP and KH-602 on the performance of the WPU coatings were investigated by analyzing the adhesion, mechanical, and thermal properties. The results showed that the thermal stability of the polyurethane coatings was significantly improved, and the decomposition temperature increased from 190.3 °C to 274 °C at a weight loss of 5 %. In addition, the water contact angle increased from 63.4° to 75.5° with the increase in polysiloxane content in the coating. This increase in hydrophobicity was accompanied by a significant increase in bond strength, with peel strength increasing 2.44-fold from 1.19 to 2.91 N/mm. This innovative formulation has excellent heat resistance and adhesion properties and therefore has potential for a wide range of applications in waterborne polyurethane coatings.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 133
·期 1
·
IF 1.768
Yue Zhu,Xiang Gao,Yingwu Luo
Poly(methyl methacrylate) (PMMA) block copolymer is interesting because it is compatible with many polymers. A series of poly(methyl methacrylate)- b -poly( n -butyl acrylate) (PMMA- b -PnBA) diblock copolymers with various compositions was synthesized via reversible addition–fragmentation chain-transfer (RAFT) emulsion polymerization with the amphiphilic oligo(methacrylic acid 41 - b -methyl methacrylate 8 ) RAFT agent as both the polymerization mediator and surfactant. The molecular weights of the block copolymers agreed well with the theoretical prediction, although the polydispersity indices were relatively broad. The resulting core [poly( n -butyl acrylate)]–shell (PMMA) particles of PMMA- b -PnBA were found to be very effective impact modifiers for polycarbonate (PC). The diblock copolymer was well dispersed in 100–300-nm particles in the PC matrix, and the dispersed particle size was highly dependent on the block copolymer compositions. PMMA 250 - b -PnBA 550 (the subscripted number signifies the designed degree of polymerization), which was dispersed into 100-nm particles, presented the best capability for improving the impacting properties. Compared with the neat PC, the notched impact strength of PC toughened by 5 wt % PMMA 250 - b -PnBA 550 was increased by four times to 62.81 kJ/m 2 with the same yield strength, a slightly decreased modulus, an increased elongation at break, and an increased tensile strength. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132 , 42833.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Yanyan Wang,Yao Qin,Xiangyuan Li,Jingbo Zhao
Under the background of sustainable development in polyurethane field, the aminolysis of cyclic carbonates (CCs) is one of the most promising and competitive ways to prepare non-isocyanate polyurethane (NIPUs). Nowadays, most of the 5-membered CCs are synthesized by a catalytic cyclocarbonation of epoxides with CO 2 . In this study, a new dicyclocarbonate with a hexanediamide unit (HDADC) was prepared through a CO 2 -free green route. A hexanediamide tetraol (HDATL) was synthesized first by the amidation of dimethyl adipate (DMA) with 3-amino-1,2-propanediol (3-APDL), and then HDADC was prepared by the cyclocarbonation of HDATL with excess ethylene carbonate (EC). Four bio-based linear NIPUs containing polyitaconamide (PIA) sequences (L-NIPUs) were prepared via a solvent-free and catalyst-free aminolysis of HDADC with H 2 N-terminated PIA prepolymers. The L-NIPUs exhibited tensile strength up to 27 MPa and the maximum elongation at break of 392 %. Easy hydrogen bonding of the hexanediamide and flexible PIA segments made the L-NIPUs show excellent toughness and high mechanical property. An efficient and green route was established to synthesize hexanediamide dicyclocarbonate from DMA, 3-APDL, and EC under normal pressure. Bio-based L-NIPUs were prepared and showed good mechanical property.
研究领域:
材料科学
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化学工程
·
可持续发展
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DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 11
·2640
·
IF 3.426
Peng Dong,Jing Feng,Sujuan Li,Tingli Sun,Qingshan Shi,Xiaobao Xie
Starting from primary amine bearing cyclic carbonatetert-butyl-(2-oxo-1,3-dioxan-5-yl) carbamate (TBODC) and caprolactone (CL), amphiphilic poly(caprolactone-ran-amino trimethyl carbonate)s (P(CL-ran-ATC)s) random copolymers with controlled molecular weight and composition were synthesized via ring opening polymerization (ROP) and deprotection, using stannous octoate (Sn(Oct)2) as catalyst and benzyl alcohol (BnOH) as initiator. Therefore, hydrophilic/lipophilic ratio (HLR) of the P(CL-ran-ATC)s copolymers can be finely adjusted by the feed ratio of TBODC and CL. The antimicrobial activity againstStaphylococcus aureus(S. aureus) andEscherichia coli(E. coli) of P(CL-ran-ATC)s were proportional to HLR, and P(CL-ran-ATC)s presented more vigorous bactericidal activity towardsS. aureus. The minimum inhibitory concentration (MIC) values of P(CL-ran-ATC 50.9%) are 2000 μg mL−1and 3000 μg mL−1forS. aureusandE. coli. While P(CL-ran-ATC 50.9%) exhibited deficient hemolytic activity as 1.41%. In addition, the P(CL-ran-ATC)s showed extremely low cytotoxicity towards fibroblast L929 cells.Keywords:cyclic carbonate;primary amine;poly(ester-carbonate)s;antimicrobial activity;low hemolysis and cytotoxicity
研究领域:
高分子化学
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材料科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2018
·
IF 3.468
Chuanchuan Liu,Qiang Yao
The thermal degradation of resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP) has been studied by 31 P NMR, Q-TOF, and GPC at normal and extreme heating conditions. The thermal degradation begins with the elimination reaction that generates reactive monomers and arynes. The aryne-bisphosphate adducts or their decomposition products were identified through Q-TOF analysis. Through the intertwined condensations, transesterifications, and elimination reactions, the reactive acid phosphates are formed and eventually convert the bisphosphates into volatile triphenyl phosphate, oligomeric aryl/acid polyphosphates, and non-volatile polyphosphoric acid. It is these reactions and products that provide the bisphosphates effective pathways for entry into the vapor phase or action in the condensed phase. The facility of these reactions, particularly the elimination reaction that is the initiation step, to occur is critical for the high efficiency of flame retardancy displayed by the bisphosphates. A thermal Melvin rearrangement of the bisphosphates to arylphosphonates has also been established.
研究领域:
材料科学
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化学
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高分子科学
·
分析化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Ngoc Khanh Tran,Duraisamy Senthil Raja,Yen-Te Lee,Tien Khoa Le,De-Hao Tsai
Glycerol carbonate (GLC) offers a range of benefits including biodegradability , versatility, and its potential for carbon capture and utilization. Base catalysts play a crucial role for GLC synthesis by facilitating the activation of reactants, enhancing nucleophilicity , accelerating reaction kinetics, and enabling catalyst regeneration . In this study, metal–organic framework (MOF) derived hybrid structure, CaO-MgO@Al 2 O 3 , was developed as a base catalyst to promote transesterification of glycerol with dimethyl carbonate (DMC) to form GLC. The results show that hydrothermal plus wet-impregnation routes formed the hybrid nanostructure with homogenously dispersed Ca, Mg and Al elements. Further, the synthesized catalysts showed significantly high specific surface area and basicity (2.656 mmol g −1 ). High selectivity (>99 %) and high GLC yield (96.2 %; 208.9 mmol g-cat −1 ) were achievable. This study demonstrated the rational design concept of MOF-derived hybrid structures used in the enhancement of base catalysis for transesterification of DMC to GLC, offering an effective solution with mild reaction conditions and high conversion.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Nan Liu,Fahu Yang,Dong Liu,Fei Chen
Polyesters are extensively utilized across various fields due to their superior physical and chemical properties; enhancing the toughness of polyesters is currently imperative for extending their applications. In this study, a novel acrylate elastomer (BMHx) with controllable hydroxyl groups was designed to melt-blend with polyethylene naphthalene (PEN), to enhance the fracture toughness of PEN. The hydroxyl group in BMHx can effectively enhance the compatibility of PEN and BMHx, thus reducing the average particle size of BMHx to endow it to disperse in PEN more uniformly, leading to a high toughness PEN material. The tensile toughness of PEN/BMH10 can reach 4.01 MJ/m3, and the notched impact strength is 8.02 kJ/m2, which are 18 times and 3.8 times higher than that of PEN, respectively. These findings provide a new strategy to toughen the polyester and thus a general usefulness.
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
高影响因子
危险品化学品经营许可证（带存储）