JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 58
·期 22
·3183-3195
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IF 0
Ruilu Guo,Yuemin Liu,Lixia Zhou,Na Li,Guangxin Chen,Zheng Zhou,Qifang Li
There are many benefits associated with thermoplastic silicones, but very few examples exist: silicone resins or rubbers are normally thermosets. In this article, a facile and efficient approach was reported to prepare thermoplastic silicone by introducing a bulky side siloxane group. Monofunctional polyhedral oligomeric silsesquioxane (POSS), as the bulky siloxane group, was grafted onto the linear polysiloxane backbone via thiol–ene click reaction, endowing the liquid polysiloxane with thermoplastic nature. The POSS-grafted polysiloxane could be remolded by a hot-melting or solution casting process. It was worth noting that the novel thermoplastic silicone was composed of both linear siloxane main chains and siloxane side groups, which was distinctly different from previous researches on thermoplastic silicones consisted of siloxane main chains and organic side groups. Thermal analysis, rheological characterization and molecular dynamics simulation results revealed the thermoplastic properties of POSS-grafted polysiloxane depended on the bulky POSS's hindrance to the movement of the polymer backbone rather than the interaction between the organic side groups. Graphical Due to various applications of silicone materials, thermosetting silicone material waste has accumulated tremendously. Attempt to ease this situation, a new type of transparent thermoplastic silicone resin material is developed and may broaden its future use. The synthesis method enriches the types of thermoplastic silicones and provides a new idea for the recovery and reuse of silicone materials.
研究领域:
材料科学
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高分子化学
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DOI
Applied Sciences-Basel
·
2023
·Vol. 13
·期 9
·5726
·
IF 2.7
Yujia Chen,Wei Tan,Li Li,Hongbing Ji
It is a challenge to research and develop silicon surfactants with good acid and alkali stability. In the present paper, methylpropenyl polyether modified nonionic silicone surfactant (MPNTS), an alkali-resistant and hydrolysis-resistant silicone surfactant, was synthesized by hydrosilylation of 1,1,1,3,5,5,5-heptamethyl trisiloxane (MDHM) and methylpropenyl polyether (EO(7)). The polyether segments are grafted onto the main chain of organosilicon heptamethyl trisiloxane at a molar ratio of 1:1.05 (n(Si-H):n(C=C)). To evidence product formation, the MPNTS were analyzed by FT-IR and1H NMR spectroscopy. The surface tension of NPNTS is 18.68 mN/m, and the CMC value is 78 mg/L by a contact angle tester. MPTNS shows hydrolytic stability and maintains that it could keep surface activity after standing for 60 days at pH = 7–10. The compatibility performance analysis shows that MPNTS has good compatibility and synergy with cationic, anionic, and nonionic surfactants, and it reveals the application prospects in daily chemicals, agricultural adjuvants, and other products.Keywords:silicone surfactant;trisiloxane;stability;synergy
研究领域:
化学
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材料科学
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表面活性剂技术
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 16
·7469-7479
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IF 2.7
Zhu Yuqin,Wang Di,Guo Zhongliang,Wen Huiying
In this paper, flame retardant composites were prepared by incorporating three flame retardants (FRs), including triphenyl phosphate (TPP), polysiloxane (PSQ) and phosphite functionalized polysiloxane (PPSQ), respectively into a polylactic acid (s/PLLA) matrix. The results indicated that the ultimate oxygen index increased from 20.6% (s/PLLA) to 22.5% (s/PLLA/TPP), 21.1% (s/PLLA/PSQ), and 23.3% (s/PLLA/PPSQ). The composites exhibited a decrease in peak heat release rate (pHRR) and prolonged peak time according to the cone calorimetry analysis. s/PLLA/PPSQ possessed the highest residual carbon content and the densest char residue with finest and smallest pores, indicating excellent flame-retardant performance. The crystallization behavior analysis revealed that the three FRs resulted in an increased crystallization rate and crystallinity. Notably, the crystallinity of s/PLLA/PPSQ increased from 25.8% in s/PLLA to 37.3%. Additionally, PSQ and PPSQ effectively enhanced the mechanical properties of composite materials. Compared to s/PLLA, the tensile strength of s/PLLA/PSQ and s/PLLA/PPSQ increased by 11.5% and 31.3% respectively, and storage modulus increased by 50.0% and 14.6%. This research demonstrated that among the three additives, PPSQ can effectively provide both flame retardancy and mechanical properties to the s/PLLA matrix, resulting in the composite with the best comprehensive performance.
研究领域:
材料科学
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聚合物工程
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DOI
高影响因子
BIOMASS & BIOENERGY
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2022
·
IF 5.774
Jia Wang,Liwei Liao,Li'ao Wang,Lei Wang
There has been no standard method for sampling and analysis of siloxane in biogas . The appropriate sampling method must ensure that the composition of samples collected in siloxanes does not change during sampling and analysis. To this end, three sampling methods (two-tandem (section A and B)) impingers with acetone as absorbent (TTIA), coconut activated carbon adsorbent tubes (CACT), and silica gel adsorbent tubes (SGT)) were evaluated in this paper. Hexamethyldisiloxane (L2), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5) detected in section B were less than 7% of those in section A of the three methods. The gas chromatography coupled with mass spectrometry (GC-MS) was used for quantitative analysis of the siloxane in the samples. The results demonstrated that target compounds were completely adsorbed by the three methods. For D3, D4, and D5, recovery rates of CACT were 103%, 126%, and 120%, recovery rates of SGT were 114%, 112%, and 114%, and recovery rates of TTIA were 45%, 86%, and 92%, respectively. According to the one-way analysis of variance test, there was no significant difference between recovery rates of CACT and SGT, whereas they were higher than those of TTIA. The siloxane contents in dry synthesis gas collected by three methods were generally higher than those in wet synthesis gas. The contents of D3, D4, and D5 did not change significantly with storage temperatures except L2. However, the content of D3 stored at 25 °C was unstable over time, which reduced by 16% on average at 12 h.
研究领域:
环境科学
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分析化学
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DOI
高影响因子
RENEWABLE ENERGY
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2024
·
IF 9
Siqi Lv,Rui Zhang,Yuanping He,Zichuan Ma,Xiaolong Ma
Volatile methyl siloxanes (VMSs), which are converted to silica sediments during biogas burning, are regarded as the most problematic VMSs in existing biogas cleaning systems. However, the majority of methods for VMS removal, including cryogenic condensation, physical absorption, chemical absorption and porous material adsorption have been constrained by these methods' intrinsic drawbacks. Here, we present an alternate method for removing VMS from gas streams that are based on the materials supported by H 2 SO 4 . Simple incipient wetness impregnation was used to create MCM-41-supported H 2 SO 4 (SSA/MCM) materials, which showed high reactive adsorption property for hexamethyldisiloxane (L2) elimination in the temperature range of 80–160 °C with the peak reactivity at 100 °C. With maximum Q B and Q m values of 191.3 and 365.6 mg g −1 , respectively, dynamic adsorption findings showed the significance of altering the intake concentration, gas flow rate, adsorbent mass, relative humidity, as well as H 2 SO 4 loading in determining the L2 removal efficacy. Furthermore, it was established that the L2 reactive adsorption was caused by the polymerization of L2 by supported H 2 SO 4 , which produced the creation of polysiloxane. The findings offer an important foundation for creating a cutting-edge biogas cleaning method.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 21
·10237-10245
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IF 3.925
Yunfan Xu,Mengdong Guo,Shilong Lu,Zengyue Wei,Shengyu Feng
To reduce the pressing environmental concerns and negative environmental impact of non-recyclable materials, recyclable polymers pose promising and useful solutions. In this work, recyclable poly(sulfone siloxane)s were synthesized by the introduction of siloxane units into the main chain of aliphatic polysulfones via ring-opening polymerization of three types of sulfone-containing cyclosiloxane monomers with different lengths of alkyl segments. The results of wide-angle X-ray diffraction analysis revealed that the prepared polymers were amorphous. Thermal properties of the recyclable poly(sulfone siloxane)s were further investigated by differential scanning calorimetry and thermogravimetric analysis. Moreover, poly(sulfone siloxane)s were selectively depolymerized into the initial cyclic monomers using KHSO4 in an aqueous tetrahydrofuran solution at room temperature, suggesting the recyclability of the polymers. This work may provide a simple and useful strategy to design novel poly(sulfone siloxane)s with good solubility and recyclability.
研究领域:
材料科学
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环境科学
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高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
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IF 2
Zhen Chen,ZhanKun Jiang,Jinyi Chen,Ping Lu,Chao Hua,Qing Yuan
The vapor–liquid equilibrium (VLE) data for decamethyltetrasiloxane (MD2M) and dodecamethylpentasiloxane (MD3M) are pivotal for efficient distillation separation process in the silicone industry. The isobaric VLE data for the binary system of MD2M + MD3M were determined at 11.0, 50.0, and 101.3 kPa using a modified Othmer still. The experimental data satisfied thermodynamic consistency tests, including Herington’s method and the Van Ness criterion. The VLE data were fitted using the NRTL, UNIQUAC, and Wilson activity coefficient models. The results show that the UNIQUAC model performs slightly better than the other models. The VLE data and model parameters reported here are essential for the design and simulation of separation processes for MD2M and MD3M, contributing valuable insights for industrial-scale operations.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2020
·Vol. 306
·期 3
·2000621
·
IF 3.853
Peng Wang,Lei Yang,Mingqi Sun,Zhenhuai Yang,Shuai Guo,Gang Gao,Liangge Xu,Dongchao Ji,Wenxin Cao,Jiaqi Zhu
The fabrication of silicon elastomer with good mechanical properties and self-healing ability is still a challenge. Herein, a facile method to fabricate a transparent healable double-network (DN) elastomer by introducing polyborosiloxane (PBS) into self-healing polydimethylsiloxane (HPDMS) networks is demonstrated. Tensile testing shows that the mechanical properties of PBS and HPDMS are both improved. The DN elastomer shows high transparency across the visible spectrum with an average transmittance of 75%. Because of the breakage and reconstruction of reversible imine bonds and B O dative bonds, the elastomer exhibits excellent self-healing properties with a maximum healing efficiency of 98% at room temperature. Meanwhile, the elastomer can be repeatedly reprocessed with a recovery of 85% of virgin mechanical strengths. This work provides a new insight to design transparent, self-healing silicone elastomers with a simple and eco-friendly method.
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
MATERIALS LETTERS
·
2015
·
IF 2.489
Chaohong Dong,Zhou Lu,Fengjun Zhang,Ping Zhu,Lin Zhang,Shuying Sui
Iodine butyl- N -sulfonate amino polysiloxane [(IB- N -SA) PDMS] was synthesized as a novel water repellent and flame retardant and it was characterized by FT-IR. The water repellency of treated cotton fabric with (IB-N-SA) PDMS was studied and the results showed that the water contact angle increased from 88.37° to 124.49°. The flame retardant properties of treated cotton fabric were evaluated by limiting oxygen index (LOI) and the vertical burning test. The treated cotton fabric obtained good flame retardancy with a LOI value of 30.9%. Furthermore, The combustion properties of treated cotton fabric were assessed by cone calorimeter and it demonstrated that the treated cotton fabric with (IB-N-SA) PDMS generated less combustion heat and obtained better flame retardancy which can be confirmed by the increase of TTI and FPI values and the decrease in the values of HRR, THR, EHC, Mass loss and CO 2 /CO ratio.
研究领域:
纺织化学
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材料科学
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产品关联
DOI
高影响因子
MOLECULES
·
2021
·Vol. 26
·期 4
·1130
·
IF 4.412
Xifeng Hou,Yanhui Zheng,Xiaolong Ma,Yuheng Liu,Zichuan Ma
To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association withSBET,Vmicroand contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas.Keywords:reduced graphene oxide aerogel;hexamethyldisiloxane;adsorption;hydrophobicity;siloxane
研究领域:
材料科学
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环境工程
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 18
·9901-9909
·
IF 2.936
Chunyu Zhang,Lijie Qu,Yingnan Wang,Tianlu Xu,Chunling Zhang
An effective method was described here to improve the thermal insulation and stability of polysiloxane foam (SIF) by controlling the chain length of hydroxyl-terminated polydimethylsiloxane (OH-PDMS). A series of SIFs were prepared through foaming and cross-linking processes with different cross-linking densities. The morphology of SIF was investigated by environmental scanning electron microscopy. The results demonstrated that increasing the chain length of OH-PDMS reduced the average cell size from 932 μm to 220 μm. Cell density ranged from 4.92 × 106 cells per cm3 to 1.64 × 108 cells per cm3. The thermal insulation capability was significantly enhanced, and the SIF derived from the long-chain OH-PDMSs yielded a minimum thermal conductivity of 0.077 W mK−1. Cell size reduction and an increase in cell density were considered to be the main factors to reduce thermal conductivity. Thermal stability, which was also improved, mainly depended on the free motion rate of the polysiloxane chains and cross-linking density of the polysiloxane networks.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR RESEARCH
·
2017
·Vol. 25
·期 11
·1076-1084
·
IF 1.405
Li Linshuang,Xu Yong,Che Jianfei,Su Xu,Song Chaoran,M Xiuping
A series of fluorinated poly(imide siloxane) (PIS) copolymers were prepared with fluorine dianhydride 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and two kinds of functional diamine, 2,2'-bis(trifluoromethyl)-[ 1,1'-biphenyl]-4,4'-diamine (TFMB) and 1,3-bis(3-aminopropyl) tetramethyldisiloxane (GAPD) via a conventional two-stage process with thermal imidization. The soft and hard segments in the copolymer chain were composed of 6FDA-GAPD and 6FDA-TFMB, respectively. The structure of the resulting copolymers was determined by Fourier transform infrared (FT-IR) and 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy. Optical, adhesion, mechanical, and thermal properties of these PIS copolymers have been evaluated with respect to real siloxane loading kept to 0, 1.4, 2.6, 4.1, and 5.5 wt% in the copolymers, which is lower than the theoretical content of siloxane loading due to a disproportionation reaction of the siloxane chain. The resulting PIS copolymers showed excellent optical transparency in the UV-visible range and good adhesion property. The cutoff absorption wavelength ( λ 0 ) of the resulting PIS copolymers films was less than 345 nm and the maximum transmittance ( λ max ) was up to 91%. The introduction of siloxane segment dramatically improved the adhesion property of PIS copolymers from 1.29 to 2.26 MPa (measured by means of shear strength) compared to the fluorinated homopolyimide (6FDA-TFMB) synthesized without siloxane moiety. The thermal and mechanical properties of the resulting PIS copolymers decreased slightly with the increase in siloxane loading but still remain a good level. Due to the addition of trifluoromethyl (-CF 3 ) group and siloxane moiety, the solubility of PIS films was greatly enhanced and they were able to be dissolved in polar aprotic solvents, such as DMAC, DMF, and NMP. The contact angle, surface energy and water absorption were also studied in order to discuss their hydrophobic property.
研究领域:
材料科学
·
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）