POLYMER DEGRADATION AND STABILITY
·
2017
·
IF 3.386
Danfeng Zhang,Shen Yao,Shuai Li,Jun Wang,Youwei Yao
A new thermal stabilizer , La-Gly (Gly = n -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-glycin), was synthesized. Through discoloration and dehydrochlorination tests at 180 °C, La-Gly is found to possess high stabilizing efficiency for poly(vinyl chloride) (PVC): as the mass ratio of La-Gly to PVC resin is increased from 0.3/50.0 to 2.0/50.0, the time to degradation of PVC samples increases from 90 min to 190 min. Studies on combinations of La-Gly and ZnSt 2 , and of La-Gly and dibenzoyl methane (DBM) show that the initial color of PVC is improved, as the ratio of ZnSt 2 to La-Gly or DBM to La-Gly is increased from 0.3/1.2 to 1.2/0.3. One sample (50.0 g PVC, 0.6 g ZnSt 2 , 0.9 g La-Gly, 3.4 g tributyl citrate) shows the best balance between initial color and long-term thermal stability (140 min). Studies on dynamic thermal stability of the samples (50.0 g PVC, x g La-Gly, 3.4 g tributyl citrate, x = 0.3, 0.6, 0.9, 1.2, 1.5, 2.0) show that when x equals 1.2, the thermal dynamic stability time is 24.5 min, much longer than 6.4 min and 4.8 min, respectively, for two controls (50.0 g PVC, 1.5 g LaSt 3 , 3.4 g tributyl citrate; 50.0 g PVC, 0.6 g CaSt 2 , 0.9 g ZnSt 2 , 3.4 g tributyl citrate).
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2016
·
IF 3.12
Mei Wang,Jianling Xia,Jianchun Jiang,Shouhai Li,Kun Huang,Wei Mao,Mei Li
A novel liquid Ca/Zn thermal stabilizer was synthesized from tung-maleic anhydride (TMA) as feedstock and evaluated for its stabilizing effects on poly (vinyl chloride) (PVC). First, N -(3-amino-benzoic acid) tung-maleamic acid (ABTMA) was prepared from the ammonolysis of TMA and para -aminobenzoic acid (PABA). Then its complex calcium salt (ABTMA-Ca) and zinc salt (ABTMA-Zn) were synthesized through a one-step method, and investigated by Fourier transform infrared spectroscopy and elemental analysis . ABTMA-Ca and ABTMA-Zn were separately treated with diethylene glycol monobutyl ether at 120 °C for 3 h to form liquid ABTMA-Ca (LABTMA-Ca) and liquid ABTMA-Zn (LABTMA-Zn). The effects of LABTMA-Ca/LABTMA-Zn, CaSt 2 /ZnSt 2 and C36DA-Ca/C36DA-Zn on thermal stability of PVC were studied through Congo Red test, discoloration tests and dynamic thermal stability analysis. The LABTMA-Ca/LABTMA-Zn thermal stabilizer exhibit excellent long-term stability. Analysis of tensile and dynamic mechanical properties shows PVC samples stabilized with LABTMA-Ca/LABTMA-Zn and the other two Ca/Zn systems all display comparable strength , modulus and glass transition. A common stabilizing mechanism of LABTMA-Ca/LABTMA-Zn system and its radical mechanism were presented, respectively.
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
MATERIALS SCIENCE FORUM
·
2015
·
IF 0
Xiao Peng Xu,Si Chen,Yan Qin Shi,Bo Zhen Wu,Meng Ma,Xu Wang
The effect of orotic acid (OA) and its mixtures with calcium stearate (CaSt2) and zinc stearate (ZnSt2) in various ratios on the thermal stability of PVC has been investigated by Congo red and discoloration tests. The results shows that OA acts as a long-term thermal stabilizer for PVC like CaSt2, and the combination of OA and ZnSt2 exhibited a synergistic stabilization effect at a certain ratio. This is due to the ability of OA to absorb HCl released during the degradation of PVC to diminish its catalytic effects, and react with ZnCl2 to stop its catalytic effect for PVC. CaSt2-ZnSt2/OA stabilizers exhibit good synergistic effects with both acceptable initial color and long-term stability for PVC
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 24
·e53960
·
IF 3
Yanqin Shi,Lukai Chen,Songyan Lu,Yuchen Yao,Si Chen,Huiwen He,Meng Ma,Xu Wang
A new kind of highly efficient organic zinc thermal stabilizer for polyvinyl chloride (PVC), zinc arginine stearate [Zn(Arg)(St)], is designed by introducing the arginine and stearate to the same zinc atoms to regulate the binding energy between anions and cation. Gaussian soft is used to calculate the binding energy. The results of Fourier transform infrared spectra, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry show that Zn(Arg)(St) has been successfully synthesized. Zn(Arg)(St) stabilized PVC displays excellent Congo red, static and dynamic thermal stability time, especially the excellent initial whiteness and whiteness retention time. The thermal stability mechanism of Zn(Arg)(St) attributes to the different binding energy between the two anions and zinc cation, which results in Zn(Arg)(St) continuously replacing the unstable chlorine atoms step by step by Arg and St anions. Moreover, the amino group in Arg could complex ZnCl 2 to inhibit the “zinc burning” effect, and the guanidine group could absorb HCl to inhibit the “autocatalytic effect” of HCl. In addition, Zn(Arg)(St) has a remarkable lubrication effect, which also enhances the thermal stability of PVC. Thus, Zn(Arg)(St) is an environmentally friendly thermal stabilizer for PVC with an excellent thermal stability effect. Importantly, this work also proposes a new method to design highly efficient thermal stabilizers for PVC.
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
POLYMER DEGRADATION AND STABILITY
·
2014
·
IF 2.633
Guoan Chen,Liqiang Gu,Youwei Yao
A Zn-containing complex ([ZnL 2 ]· x H 2 O, x ≈ 4, abbreviated as ZnL 2 ; HL = 1,3-dihydroxy-2-hydroxymethyl-2-(salicylidimino)propane) was synthesized and used as a thermal stabilizer . Through discoloration and dehydrochlorination tests at 180 °C, ZnL 2 was proved to be a co-stabilizer of long-term thermal stability for poly(vinyl chloride) (PVC): compared with the PVC samples stabilized using typical metallic soap stabilizers with the mass ratio of calcium stearate (CaSt 2 ) to zinc stearate (ZnSt 2 ) ranging from 1.5/0 to 0/1.5, whose induction time ( t i ), stability time ( t s ) respectively ranged from 9 to 54 min, from 12 to 56 min, the PVC samples stabilized using combinations with the mass ratio of CaSt 2 to ZnL 2 from 1.5/0 to 0/1.5 showed apparent thermal stability with t i , t s ranging from 44 to 85 min, from 49 to 88 min. PVC sample (PVC resin = 50.0 g, ZnL 2 = 1.5 g, pentaerythritol = 0.3 g, dioctyl phthalate = 2.5 g) displayed a significant long-term thermal stability with t i of 102 min, t s of 105 min, and totally-turning-black time of 170 min.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 99
·97036-97047
·
IF 3.289
Mei Wang,Jianling Xia,Jianchun Jiang,Shouhai Li,Mei Li
Dipentene-maleic anhydride (DPMA) was prepared by the Diels–Alder addition of dipentene with maleic anhydride. DPMA was converted via ammonolysis with para-aminobenzoic acid (PABA) to form N-(3-amino-benzoic acid)terpene-maleamic acid (ABDPMA), which was then converted to zinc soap (ABDPMA-Zn) or calcium soap (ABDPMA-Ca). Their chemical structures were confirmed by FT-IR and ICP-AES. Thermal stabilizing effects of ABDPMA-Ca/ABDPMA-Zn were compared with ABTMA-Ca/ABTMA-Zn (ABTMA: N-(3-amino-benzoic acid)tung-maleamic acid), C36DA-Ca/C36DA-Zn (C36DA: dimer fatty acid), ZnMA/ZnO (MA: maleic acid), EFC/ZnSt2/ESBO (EFC: calcium salt of epoxidised fatty acid; ESBO: epoxidised soybean oil, and CaSt2/ZnSt2 (St: stearic acid). Thermal stabilities of poly(vinyl chloride) (PVC) compounds were determined using Congo Red test, discoloration test, ultraviolet-visible spectroscopy analysis and thermogravimetric analysis. Dynamic mechanical and tensile properties of the PVC compounds were also studied. Besides better plasticization performance, ABDPMA-Ca/ABDPMA-Zn improved the long thermal stability of PVC compared with ABTMA-Ca/ABTMA-Zn, C36DA-Ca/C36DA-Zn, and CaSt2/ZnSt2.
研究领域:
高分子化学
·
材料科学
·
塑料加工
·
热稳定化
·
功能添加剂
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2017
·
IF 3.386
Mei Li,Jianling Xia,Haiyang Ding,Chengxiang Ding,Mei Wang,Shouhai Li
An adduct of myrcene and maleic anhydride (AMMA) was synthesized using a Diels-Alder reaction. The adduct was transformed into the corresponding sodium , calcium salt and zinc salts (Na-AMMA, Ca-AMMA, and Zn-AMMA) using a metathesis reaction . The chemical structures of AMMA, Na-AMMA, Ca-AMMA, and Zn-AMMA were confirmed with Fourier transform infrared spectroscopy (FTIR), Inductively coupled plasma-atomic emission spectrometry (ICP-AES), 1 H and 13 C nuclear magnetic resonance ( 1 H NMR and 13 C NMR), and X-Ray Diffraction (XRD). Mixed Ca/Na/Zn salts from AMMA provided thermal stabilization for poly (vinyl chloride) (PVC). The thermal and mechanical properties of the PVC samples were investigated using discoloration and Congo red tests, scanning electron microscopy analysis (SEM), thermal gravity analysis (TGA), TGA–FTIR analysis, thermal gravity-mass spectrometer analysis (TGA-MS), and dynamic mechanical analysis (DMA). Optimal design of the Ca/Na/Zn-AMMA formulation was studied. The application of Ca/Na/Zn-AMMA in an optimized formulation for a biobased, primary thermal stabilizer for PVC could significantly improve PVC thermal stability. The optimized Ca/Na/Zn-AMMA formulation had higher thermal stability, higher storage modulus , and lower glass transition temperatures than PVC blends without any thermal stabilizers and using commercial CaSt 2 /ZnSt 2 . The weights of the Ca/Na/Zn-AMMA samples were 33.3–75.0% that of CaSt 2 /ZnSt 2 , but provided higher thermal stability. Myrcene-derived Ca/Na/Zn-AMMA was shown to have strong potential as a primary PVC thermal stabilizer.
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Yuewen Shao,Kai Sun,Mengjiao Fan,Guoming Gao,Junzhe Wang,Lijun Zhang,Shu Zhang,Xun Hu
Copper-based catalysts are active for hydrogenation, while they are prone to sintering in hydrothermal conditions. In this study, alloying Cu with Ni and Zn was adopted to suppress sintering of copper species in the catalyzed conversion of furfural to cyclopentanone (CPO) and cyclopentanol (CPL) in the aqueous phase. The results indicated that Zn acted as a “glue” for aiding the formation of CuZn or CuNiZn alloy. The formation of the ternary CuNiZn alloy in CuNiZn/Al2O3 catalyst created the developed porous structure, induced the formation of abundant Lewis acidic sites and Brønsted acidic sites, and enhanced the dispersion and the total surface area of Cu species. These together rendered CuNiZn/Al2O3 with superior activity to monometallic or bimetallic Cu-based catalysts for the production of CPO and CPL (sum yield of 86% over Cu1.0Ni1.0Zn1.0/Al2O3), which was attributed to the synergy between CuNiZn alloy and Brønsted acidic sites. Alloying Ni with Cu and Zn weakened the adsorption of the C═C bond in the furan ring of furfural, while enhancing the activation of C═O and C–O–C bonds in furfural, avoiding the deep hydrogenation of the furan ring, facilitating the rearrangement of furfuryl alcohol to CPO, and improving the turnover frequency for the production of CPO from furfural remarkably (1011.3 h–1 over Cu1.0Ni1.0Zn1.0/Al2O3 vs 23.9 h–1 over Cu1.0/Al2O3). The formation of ternary CuNiZn alloy could not only suppress the sintering of metallic Cu species during the reduction in hydrogen but also effectively prevent the aggregation of Cu species in the aqueous phase, enhancing the catalytic stability under hydrothermal conditions.
研究领域:
催化化学
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Yanqin Shi,Songyan Lu,Biao Ma,Si Chen,Meng Ma,Huiwen He,Xu Wang
A bis-uracil derivative with a long aliphatic chain of 11 carbon atoms, USU-C, was synthesized by an optimized method. The migration rate test indicated that USU-C had better migration resistance compared to OSU. This advantage enabled the PVC samples containing USU-C to maintain good transparency and low haze for a long time. It had also been proven USU-C has better thermal stability and whiteness retention than OSU by the thermal stability tests. Based on summarizing this work and our previous studies, a new design method was proposed to enhance the transparency and thermal stability effect of thermal stabilizers on PVC based on Hansen solubility parameters (HSP) theory. Impressively, the quantitative mathematical function between the HSP and the carbon atom number in the long aliphatic chain of bis-uracil derivatives was also derived, which could be used to guide the structure design of new bis-uracil derivatives with long term migration resistance, preeminent transparency, and high thermal stability for PVC in the follow-up study, even other organic thermal stabilizers.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Wenhua Feng,Ze Xiao,Binyi Chen,Yunhong Pi,Changsong Hu,Wenli Zhang,Qingwei Meng,Tiejun Wang
As non-noble metal catalyst, Cu-based catalyst shows promising applying potential in the aqueous-phase reforming of methanol (APRM) due to its high dehydrogenation activity and low CO selectivity, but the poor thermal and hydrothermal stability. Herein, a Cu@S-1 catalyst with ultrasmall-2nm Cu nanoparticles size was synthesized for the first time using one-step in-situ encapsulation strategy. By the confinement effect of the zeolite Silicalite-1 (S-1) micropores, the 1 wt%Cu@S-1 catalyst exhibited absolutely superior thermal stability without using any other promoter, as well as relatively good hydrothermal stability. After 600–700 °C high-temperature treatment, no obvious aggregation of the Cu nanoparticles was found, and superior performance in the steam reforming of methanol (SRM) was maintained after running for 36 h at 300 °C. In the APRM at 210 °C, the 1 wt%Cu@S-1 catalyst showed six-fold higher hydrogen releasing rate (4.26 × 10 5 μ mo l H 2 · g Cu − 1 · h − 1 ) than the impregnated 1 wt%Cu/S-1-im catalyst, meanwhile it exhibited even better performance than the commercial 5%Pd/C catalyst. Compared with the impregnated 1 wt%Cu/S-1-im catalyst, the confinement effect of the internal pores of the S-1 for the Cu nanoparticles in the 1 wt%Cu@S-1 catalyst effectively inhibited aggregation of the Cu particles and Cu leaching in APRM, thus greatly improved the activity and hydrothermal stability.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2022
·Vol. 85
·期 5
·1636-1647
·
IF 2.43
Jin Yuning,Wu Danping,Ma Na,Dai Wei
MOFs (metal-organic frameworks) significantly suffer from water- and heat instable issues, restricting their practical application, such as the capture of hazardous anionic dyes (e.g. Congo red, CR) from water. In the present contribution, a series of novel composites (UiO-67@CNTs) composed of microporous UiO-67 (Zr6O4(OH)4(CO2)12) and mesoporous CNTs (carbon nanotubes) have been innovatively synthesized by an in-situ hydrothermal reaction strategy. This UiO-67@CNT impressively retains structural integrity whether contacted with strong acid, distilled water, and strong alkali conditions even for 20 days. Due to the existence of CNT, its heat stability can reach up to 480 °C, which is superior to that of UiO-67. Open Zr(IV) sites, mesoporous, and high surface area in the structure of UiO-67@CNTs play associative effects for CR capture ability. CR uptakes over (5.0)UiO-67@CNTs can reach 1024 mg/g, exceeding some other previous adsorbents in literature. Importantly, UiO-67@CNTs could retain a remarkable CR capture ability even after the fifth cycle. This work expands views for water-heat resistant MOF-based composite with excellent ability of CR capture. UiO-67@CNTs exhibited outstanding hydrolytic stability, retaining intactness for 20 days even in strong acid and alkali. UiO-67@CNTs performed more excellent thermal stability until 480 °C. Novel UiO-67@CNTs have potential applications for CR capture.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 43
·49319
·
IF 2.52
Weihua Ye,Qinghua Chen,Zheng Chen,Zhi Wen,Zhengfu Liao
Uracil derivatives are potential nontoxic thermal stabilizers of poly(vinyl chloride) (PVC) and have a better stabilization effect. 5,6-diamino-1,3-dimethyluracil (DDU) was investigated as a thermal stabilizer for PVC. The stabilization effect of DDU was measured by thermogravimetric analysis, thermal aging test, and recording the time of the color change of the Congo red paper (Congo red test). Meanwhile, the processability of PVC stabilized by DDU was investigated through dynamic performance test. The results showed a better stabilizing effect compared with calcium stearate (CaSt 2 ) and zinc stearate (ZnSt 2 ). To explain the stabilization of DDU, the probable mechanism was suggested that DDU absorbed and chemically bonded with hydrogen chloride. Therefore, DDU could be used as a thermal stabilizer of PVC.
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
危险品化学品经营许可证（带存储）