REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Fada Li,Bo Chen,Yu Han,Yiwen Cao,Xiaoxue Hong,Mancai Xu
Phenol, catechol , and pyrogallol were employed as the hydrogen-bond donors to chemically modify the commercial adsorbent Amberlite XAD16 via Friedel-Crafts reaction, and three phenols-modified XAD16 were named as, XAD16-Ph(OH), XAD16-Ph(OH) 2 , and XAD16-Ph(OH) 3 respectively. The resulting polymers had porous parameters including Brunauer-Emmett-Teller (BET) surface area ( S BET ) and total pore volume ( V total ) similar to Amberlite XAD16, however the oxygen (O) content was remarkably increased after the Friedel-Crafts reaction in the presence of anhydrous FeCl 3 as catalyst. The synthesized polymers had larger equilibrium adsorption capacities toward ε-caprolactam ( q max = 69.2 mg/g) than Amberlite XAD16 due to the enhanced adsorption contributed by hydrogen bonding between the phenolic hydroxyl groups uploaded on the polymers and the carbonyl of ε-caprolactam (CPL). Experimental data indicated that the removal percentage of CPL reached 93.2% at a concentration of 0.2840 g/25 mL for XAD16-Ph(OH) 2 while the equilibrium data were fitted by the Freundlich and Langmuir models, and the kinetic data were described by the pseudo-second-order rate equation and characterized by the micropore diffusion model.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Feng-Ming He,Yan-Fang Xiao,Qin Zhang,Min Jiang,Xin Li,De-Ming Guo,Li Chen,Bo-Wen Liu,Yu-Zhong Wang
Polyamide 6 (PA 6) is an important polymer widely used in daily life. However, increasing demands for high performance and recyclability, driven by cutting-edge applications and the ongoing energy crisis, have presented major challenges to the development of PA 6. In this work, we report a simple copolymerization method to design a PA 6 copolymer with high performance and chemical recyclability. A functional monomer named ISA was synthesized via the imidization reaction between isatoic anhydride and the active amino group in α-amino-ε-caprolactam, a mature bio-based platform molecule. The chemical similarity between ISA and caprolactam (CPL) ensured high-quality polymerization, resulting in the corresponding copolymer PA 6- co -ISA with high molecular weight, excellent spinnability, great melt-crystallization performance, and mechanical robustness. As expected, high flame retardancy was obtained thanks to the gaseous dominated flame-retardant effect of the N-containing heterocyclic ring. More importantly, owing to the unchanged polymeric main chain structure, the copolymer could be easily recycled to CPL, and the repolymerized polymer showed great overall properties equal to the original one. This work provides a feasible approach for the preparation of high-performance and closed-loop recyclable polymeric materials.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 32
·25365-25371
·
IF 3.84
Yang Li,Kai Wang,Kang Qin,Tao Wang
As an important green synthesis technology of caprolactam, the Beckmann rearrangement reaction of cyclohexanone oxime using high temperature and pressure water as the reaction media was carefully studied with a microreactor. An important byproduct – acetamide was confirmed with a selectivity higher than 40% in the subcritical water, which was more serious than the reported cyclohexanone. The effects of phase state and operating conditions, such as reaction temperature, pressure, flow rate ratio and reactant residence time, on the cyclohexanone oxime conversion and caprolactam selectivity were carefully analyzed, and the results showed that keeping the reaction close to the supercritical state was critical for the preparation of caprolactam.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 58
·期 9
·1523-1529
·
IF 1.449
Yusheng Dong,Jizong Chen,Fredrick Nzioka Mutua,Yuanbo Gao,Tingting Yang,Yong He
To modify the properties of poly(hexamethylene oxamide) (PA62), amine-terminated polyoxypropylene glycols (PGs) were introduced into the polyoxamide main chain as soft segments. A series of PA62/PG2 copolymers were synthesized successfully by a two-step method. Fourier transform infrared spectroscopy, solution proton nuclear magnetic resonance spectroscopy ( 1 H-NMR), differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction were used to analyze the structures and to investigate the properties of these copolymers. The saturated water absorption was also evaluated by gravimetric analysis for PA62/PG2 copolymers. The results revealed the incorporation of PG2 effectively modified the properties of PA62 and the copolymers with PG2 content of 10–20 mol% possessed high melting point (293°C–314°C), good thermal stability and low saturated water absorption. POLYM. ENG. SCI., 58:1523–1529, 2018. © 2017 Society of Plastics Engineers
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Forests
·
2023
·Vol. 14
·期 6
·1242
·
IF 2.9
Ziheng Wang,Sheng He,Jiangtao Shi,Xuefeng Zhang,Weiqi Leng
Furfurylated wood has many advantages, such as decay resistance, dimensional stability, hardness, etc. However, furfurylation increases the brittleness and decreases the flexural resistance of wood, which greatly limits its application. Therefore, caprolactam (CPL) is incorporated with furfuryl alcohol (FA) to improve the performance of furfurylated wood. In this study, an FA and CPL combinational modifier was used to treat masson pine (Pinus massonianaLamb.) earlywood and latewood. The synergistic interaction of both components with the wood cell walls was systematically evaluated via microstructural, chemical, and thermal analysis using scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), and differential scanning calorimetry (DSC). The SEM images showed that polymerized modifiers were distributed in tracheids, ray cells, and pits, with a higher degree of distribution in latewood tissues. The FA-CPL co-treatment led to the highest degree of distribution in cell cavities as well as of cell wall swelling. The results of the weight percentage gain (WPG) of modified wood agreed with the SEM findings that the FA-CPL co-treatment could more effectively increase the WPG than individual modification. The results of FTIR and XPS revealed that FA and CPL might chemically bind with each other as well as react with lignin and hemicellulose in the cell walls during the curing process. In addition, the interactions between modifiers and cell walls were slightly different for earlywood and latewood. DSC analysis indicated that the wood hygroscopicity decreased and the thermal stability improved after modification.Keywords:furfuryl alcohol;caprolactam;vacuum impregnation;synergistic interaction;earlywood;latewood
研究领域:
材料科学
·
木材化学
·
林业
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2016
·
IF 1.846
Gan bing Yao,Zhan xiang Xia,Zhi hui Li,Chao Shao
The solid–liquid equilibrium (SLE) for ternary system of caprolactam + cyclohexanone oxime + methyl tert-butyl ether were determined at three temperatures of (278.15, 293.15 and 308.15) K under pressure of 101.2 kPa. Three isothermal phase diagrams of the system were constructed based on the measured mutual solubility data. There were two pure solids formed in the ternary phase diagram , including pure caprolactam and pure cyclohexanone oxime, which were identified by the method of Schreinemakers' wet residue. At each temperature, the phase diagram contained three crystallization regions (which corresponded to caprolactam, cyclohexanone oxime, and a mixture of caprolactam and cyclohexanone oxime), two crystallization curves, and one co-saturated point. The crystallization field of caprolactam was larger than that of cyclohexanone oxime. The NRTL model was employed to correlate and calculate the ternary phase diagram. The calculated ternary phase diagram with the NRTL model agreed well with the experimental ones. The solid–liquid phase equilibrium and phase diagram for the ternary system of caprolactam + cyclohexanone oxime + methyl tert-butyl ether could provide basis for the purification process of caprolactam.
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
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2025
·
IF 5.2
Peizhuo Han,Lei Wang,Huimin Li,Changlin Yao,Yaqian Qu,Xu Zhang,Hanlin Zhao,Yaqi Ren,Bozhang Li,Lufeng Xu,Weiguo Song,Xutang Tao
Molnupiravir (MPV) is an oral antiviral drug widely used for the treatment of coronavirus disease 2019 (COVID-19). However, the commercial form I of MPV has a poor tabletability, greatly restricting its manufacture. To solve this problem, a new cocrystal named MPV-caprolactam (CPL) was discovered by melt crystallization, and its crystal structure was successfully determined by single crystal X-ray diffraction. Meanwhile, the formation mechanism of the MPV-CPL cocrystal was studied via the formation enthalpies, and the negative formation enthalpy (−27.61 J/g at 25 ℃) is responsible for the crystallization of the MPV-CPL cocrystal. Finally, the powder tableting properties of the MPV-CPL cocrystal were investigated, and the MPV-CPL cocrystal has superior tabletability, achieving a tensile strength of 2.06 ± 0.09 MPa at 262.5 MPa compression pressure — a 1.93-fold increase over pure MPV. The MPV-CPL cocrystal also shows good compressibility, compactibility, and plasticity. This work establishes two key advances: (1) melt crystallization is a supplement to solution methods, and it can produce pharmaceutical cocrystals that tend to form solvates in solution, and (2) the improvement in tabletability of MPV-CPL cocrystal overcomes the main barrier in developing MPV tablets, which makes it a promising candidate for developing MPV tablets.
研究领域:
药学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 3.6
Yang Liu,Guodong Cao,Xuelong Zhu,Yi Zhang,Chenglu Liang,Yukun Chen
Upcycling the wasted polyamide 6 (PA6) to its monomer caprolactam via depolymerization is a promising way to build the resource cycling and alleviate the environmental pollution. High efficient catalyst for PA6 depolymerization is desirable and crucial. Herein, a sulfonated Fe-MOF catalyst was designed and performed as solid acid catalyst for the PA6 depolymerization for the first time. Results showed that a 100% conversion of PA6 solid to water-soluble liquid products can be achieved at temperatures of 250°C after only 1-h reaction. LC/MS results indicated that the water-soluble products were mainly composed of caprolactam and their oligomers. Without catalyst, nearly no water-soluble products can be obtained at the same condition. Moreover, a high selectivity of 90% caprolactam production in the water-soluble liquid products was achieved at 260°C, 5 h. The reaction rate constants at 240°C, 250°C, and 260°C were determined to be 0.024, 0.033, and 0.064, respectively, with a Ea value of 101.8 kJ/mol, showing positive temperature dependent relationship. The comparison of catalytic performances over sulfonated Fe-MOFs, FeCl 3 ·6H 2 O and the pristine un-sulfonated Fe-MOF suggested the synergistic contribution of Fe sites (Lewis acid centers) and the sulfonic acid sites to the catalytic performances. Graphical Water soluble liquid products (100 wt.%) with a high selectivity of 90% caprolactam can be achieved by the addition of Fe-MOF catalyst under a mild condition through the synergistic catalytic contribution of Fe sites (Lewis acid centers) and the sulfonic acid sites.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Zsófia Kovács,Ákos Pomázi,Andrea Toldy
The complexity of recycling crosslinked polymer composites has promoted the use of thermoplastic in situ polymerisable matrices, including ε-caprolactam-based polyamide 6 (PA6) in long-fibre reinforced composites. Their uptake by the automotive industry has created a need for adequate flame retardancy, which poses several challenges: flame retardants may hinder the in situ polymerisation reaction; moreover, the fibre reinforcement can filter out the additives not soluble in ε-caprolactam during liquid moulding composite processing, such as thermoplastic resin transfer moulding (T-RTM). We discussed the feasibility of the flame retardancy of ε-caprolactam-based PA6 and its composites, including the solubility of the additives in ε-caprolactam and their effect on the polymerisation reaction and fire performance. We evaluated the correlations between the flame retardant structure and the inhibition of polymerisation. Finally, we briefly summarised the composite processing and coating technologies suitable for preparing flame retarded ε-caprolactam-based PA6 matrix and composite systems, as well as the most often used tests for their characterisation.
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
Polymer Chemistry
·
2019
·Vol. 11
·期 6
·1211-1219
·
IF 4.76
Fu-Rong Zeng,Jing Xu,Lin-Hao Sun,Jimei Ma,Hong Jiang,Zi-Long Li
Poly(ester amide)s (PEAs) attract considerable attention owing to their intriguing properties. However, the establishment of precise structure–property relationship for PEAs is hindered by the ambiguous primary structures of these biologically important polymers. Herein, we propose polyesterification as an efficient strategy for the synthesis of copolymers of ε-caprolactone (CLo) and ε-caprolactam (CLa). Two sorts of AB-type monomers bearing halogen and carboxylic acid terminal groups, namely 6-bromohexanoic acid (1) and 6-(6-bromohexanamido)hexanoic acid (2), underwent nucleophilic substitution in a step-growth manner to furnish P(CLo) (P0) and P(CLo-alt-CLa) (P5), respectively. Moreover, random copolymers P1–P4 were also synthesized by copolymerization of 1 and 2 in predetermined feed ratios. Thermal properties, crystal structure, surface wettability, thermal responsiveness and degradation profiles of P0–P5 along with P(CLa) (P6) were investigated. The melting ranges of polymers P0–P6 become narrowed if the structural regularity is pronounced, and the melting temperatures (Tms) are fundamentally determined by chemical composition and sequence distribution. The crystal structures and morphologies of P0–P6 are influenced by their chemical compositions, and the unit cell changes from orthorhombic to α-monoclinic while increasing the molar fraction of the CLa unit. Moreover, alternating copolymer P5 shows upper critical solution temperature (UCST) behavior in dimethyl sulfoxide (DMSO).
研究领域:
高分子化学
·
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Green Chemical Engineering
·
2023
·
IF 0
Xin Guo,Zhiyuan Wang,Ye Yang,Jiahui Zhang,Yanduo Liu,Zhiyuan Mu,Siqi Jiang,Chunxiao Ren,Dan Lv,Yufeng Hu,Zhichang Liu
A production technique with the high yield and environmentally friendly process need be developed for ε-Caprolactam (CPL) in the chemical industry. This technology is highly desired to design and synthesize high−performance catalysts for liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) to CPL. In this work, 3-methyl-1-(propyl-4-sulfonyl) imidazolium methanesulfonate ([PHSO 3 MIM][MSA]) with highly efficient and excellent yield is synthesized successfully. When the optimum molar ratio of ZnCl 2 over [PHSO 3 MIM][MSA] was 0.02, it exhibits the high selectivity (94%) of CPL at 90 °C for 1 h. Interestingly, Fourier-transform infrared (FT-IR) investigations show that the functional Brønsted−Lewis acidic types of ionic liquids (ILs) are formed by the uniformly distributed ZnCl 2 and [PHSO 3 MIM][MSA]. In addition, the hydrogen bond (H-bond) is formed between CHO and ILs. After ten reaction cycles, no significant structure changes are observed in the recovered [PHSO 3 MIM][MSA]·ZnCl 2 . The solubilities of ILs are predicted by using COSMO-RS model, the results show that [PHSO 3 MIM][MSA] is a promising candidate for the liquid phase Beckmann rearrangement of CHO into CPL. Finally, a theoretical model of the H-bond interactions between ILs and CHO is further confirmed to support the advance of reaction mechanism. A feasible way is provided for the CPL production technique in the liquid phase Beckmann rearrangement reaction.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Mingzhe Jiang,Hao Tan,Lixin Jiang,Jintang Duan,Xueping Gu,Lianfang Feng,Cailiang Zhang
The anionic ring-opening polymerization of ε-caprolactam (CL) offers significant potential for producing polyamide 6 (PA6). To establish optimal conditions for designing an efficient and continuous PA6 production process, this study examines the anionic polymerization of CL at temperatures above the crystallization point of PA6. The focus is on the effects of the temperature, activator type and concentration, and catalyst concentration on the polymerization process and product characteristics. At 220 °C, the use of bifunctional methylene diphenyl diisocyanate (MDI) as an activator initiates cross-linking reactions, producing insoluble, nonmelting PA6. In contrast, anionic polymerization without an activator prevents gel formation but results in uncontrollably high molecular weights. The introduction of monofunctional N-acetyl caprolactam (AcCL) as an activator eliminates cross-linking reactions at temperatures above 220 °C while allowing precise control of the product’s molecular weight through adjustments in AcCL concentration.
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）