POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Yaoyuan Xu,Jun Long,Runze Zhang,Yunzhe Du,Shengjie Guan,Yuying Wang,Lingyun Huang,Hongwei Wei,Li Liu,Yudong Huang
Silicone resins, due to its excellent high thermal stability, are widely applied in high-temperature environment. However, it is still a problem that the initial decomposition temperature of silicone resins is relatively low, which limits their wider applications. In this paper, three kinds of polyhedral oligomeric silsesquioxane (POSS) (aminopropyl, mercaptopropyl and chloropropyl) were synthesized and analyzed by FTIR, NMR and MS for structure characterization and purity analysis. Significant improvement of thermal stability was achieved by incorporating POSS into silicone resins. Three different POSS were used to modify silicone resins, and the effects of different POSS on thermal stability of silicone resins were studied. The results indicated that the thermal stability of octa-aminopropyl POSS modified silicone resins improved most significantly, with the decomposition temperature increased by nearly 45 °C compared with pure silicone resins. Moreover, the thermal decomposition mechanism of silicone resins with different POSS was studied, and chemical simulation indicated the thermal stability of silicone resins greatly improved by forming hydrogen bond between POSS and silicone resins. And the results showed one distinctive mode of increasing thermal stability, forming hydrogen bond to block resin chains' movements.
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
·
2024
·
IF 4.1
Yu Zhang,Gang Wang,Yuxuan Xu,Jiajun Sun,Xiaohong Zhang,Ting Zheng,Lili Zhang
The high brittleness of epoxy resin at cryogenic temperature restricts their wide application in cryogenic engineering. In this study, polyhedral oligomeric silsesquioxane (POSS) with -Si-O-Si- molecular chains were synthesized, and the mechanical properties of diglycidyl ether of bisphenol A (E51 epoxy resin) were significantly enhanced at room temperature (RT) by incorporating a 4% POSS and curing agent 4,4′-diamino-diphenylmethane (DDM) as the E51/POSS/DDM resin system. Subsequently, by adding different contents of epoxidation hydroxyl-terminated polybutadiene (EHTPB) into the E51/POSS/DDM resin system, the EHTPB-E51/POSS/DDM resin system was prepared. The investigation into the impact of EHTPB content on the mechanical properties of EHTPB-E51/POSS/DDM resin system at room temperature (RT) revealed that EHTPB-E51/POSS/DDM resin system with 10% EHTPB exhibited the most favorable results. Specifically, the elongation at break, flexural strength , and critical stress intensity factor (K IC ) were measured to be 6.82%, 143.75 MPa, and 1.83 MPa m 1/2 , respectively. These values demonstrated a notable improvement of 53.3%, 26.9%, and 86.7% compared to those for the E51/DDM resin system. Concurrently, at 77 K, the elongation at break and critical stress intensity factor (K IC ) increased by 37.8% and 73.5%, respectively. The toughening mechanism of the prepared EHTPB-E51/POSS/DDM resin system was further explored through resin-curing cross-linking simulation networks and SEM images of the fracture surface of resin samples. The study of EHTPB and POSS synergistically toughened epoxy resin provided a new efficient method to prepare epoxy resins with high toughness at low temperatures.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2019
·
IF 5.997
Yuming Chen,Peng Liang,Zhen Yue,Wei Li,Chuanding Dong,Binbo Jiang,Jingdai Wang,Yongrong Yang
Chain entanglement was very important for adjusting the processability and mechanical property of nascent ultrahigh molecular weight polyethylene (UHMWPE). So far, it is still a mystery to unravel the formation mechanism of entanglements when the ethylene polymerization is conducted by the heterogeneous catalysts. In this study, a series of weakly entangled UHMWPE was synthesized by the polyhedral oligomeric silsesquioxane/MgCl2 nanoaggregates modified Ziegler–Natta catalysts. The structure of nanoaggregates was evaluated by X-ray photoelectron spectroscopy, density functional theory simulations, and scanning probe microscope experiments, where the coordination strategy of MgCl2 and hydroxyl of POSS was investigated. These nanoaggregates presented extremely low activity on ethylene polymerization and were proved to serve as isolators for separating the active sites and growing chains. The entanglement density of nascent UHMWPE (reflected by the value of initial storage modulus G′(t=0)) was exponentially decayed with the polymerization activity of increased numbers of nanoaggregates. Importantly, this exponentially decayed effect contributed by increased numbers of POSS/MgCl2 isolators offset the rapid power function increment of entanglements upon rising the temperature, which was the essential reason for the successful synthesis of weakly entangled UHMWPE even at 85 °C. Finally, we have proposed the dependence and sensitivity of G′(t=0) (i.e., indicating the initial entanglement density of nascent polymers) on the polymerization activity, which was able to trace the formation of entanglements during polymerization through the POSS modified heterogeneous catalyst.
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 39
·49167
·
IF 2.52
Jiaqi Shang,Song Mei,Danyu Zhao,Jianping Deng
Optically active hybrid particles consisting of chiral organic component and inorganic component integrate the individual advantages of the components in one entity. This article reports a new type of optically active hybrid particles constructed by helical substituted polyacetylene and octavinyl polyhedral oligomeric silsesquioxane (OvPOSS). The hybrid particles were prepared in a two-step process. First, helical substituted polyacetylene with pendent vinyl groups was synthesized and named as macromonomer (MM). Then, hybrid particles were prepared from MM and OvPOSS by free radical suspension polymerization, in which OvPOSS acted simultaneously as comonomer and crosslinking agent. OvPOSS and MM together constituted a crosslinked network and formed spherical, porous hybrid particles. The resulting hybrid particles exhibited the desired optical activity, according to circular dichroism spectroscopy measurement. As an organic/inorganic hybrid molecule itself, OvPOSS moderately improved the thermostability of the organic component and meanwhile increased the porosity of the hybrid particles. It also helped to tune the surface morphology of the hybrid particles. The present study provides a novel class of optically active hybrid particles, and the preparation strategy may further work as a versatile platform for developing novel chiral hybrid materials.
研究领域:
材料科学
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有机化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 35
·20579-20587
·
IF 3.119
Xiaoxuan Xu,Songlong Jiao,Zhengquan Liu,Lei Liu
A porous MoS2-polyhedral oligomeric silsesquioxane (POSS) nanohybrid was prepared from octavinyl-POSS nanoparticles and MoS2 nanosheets for the first time, the structure and composition of which were confirmed by X-ray powder diffraction (XRD), Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM), energy dispersive spectra (EDS) and thermal gravimetric analysis (TGA). As a comparison, MoS2 nanosheets, octavinyl-POSS and MoS2-POSS nanohybrid were used as lubricating additives for liquid paraffin (LP), which decreased the friction coefficients of LP by 7.8% (MoS2), 14.1% (octavinyl-POSS), and 18.8% (MoS2-POSS). Compared with MoS2 and octavinyl-POSS, the MoS2-POSS nanohybrid can be dispersed in organic solvents more homogeneously without adscititious dispersants or surfactants due to its better organic compatibilities. SEM and EDS analyses indicate that a synergistic frictional effect is responsible for the improved friction-reduction and anti-wear behavior.
研究领域:
材料科学
·
摩擦学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Coatings
·
2022
·Vol. 12
·期 2
·153
·
IF 3.236
Xing Zhao,Lang Guo,Liqin Wang,Ziming Wang,Meiman Peng,Liping Zheng,Qing Niu
Moisture-curable polyurethane (MCPU) is a specifically designed material for the consolidation of fragile cultural objects in high-humidity environments. In order to solve the problem of its susceptibility to yellowing due to heat ageing, polyhedral oligomeric silsesquioxane (POSS) was added to the MCPU to prepare POSS/MCPU. The appearance, stability and mechanical properties of the POSS/MCPU films were characterized using a UV–Vis spectrophotometer, a gloss meter, a colorimeter, a thermal analyzer and a universal material testing machine. The results showed that the films are colorless and transparent and have a light transmission of over 80%. The addition of POSS has almost no effect on the chromaticity of the MCPU, while the thermal stability of the POSS/MCPU is improved compared to the pristine MCPU. The modified film is 2.50 times more resistant to yellowing by heat. The addition of POSS also simultaneously enhances the strength and toughness of the film. Using POSS/MCPU to reinforce the fragile object, the material was found to be significantly effective, indicating it has the potential to be used during the extraction of fragile cultural objects from archaeological sites.Keywords:conservation materials;moisture-curable polyurethane;POSS;consolidant
研究领域:
文物保护
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 2
·373
·
IF 3.164
Xiuhuan Song,Xiaoxiao Zhang,Tianduo Li,Zibiao Li,Hong Chi
A series of hybrid thermoplastic polyurethanes (PUs) were synthesized from bi-functional polyhedral oligomeric silsesquioxane (B-POSS) and polycaprolactone (PCL) using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent for the first time. The newly synthesized hybrid materials were fully characterized in terms of structure, morphology, thermal and mechanical performance, as well as their toughening effect toward polyesters. Thermal gravimeter analysis (TGA) and differential scanning calorimetry (DSC) showed enhanced thermal stability by 76 °C higher in decomposition temperature (Td) of the POSS PUs, and 22 °C higher glass transition temperature (Tg) when compared with control PU without POSS. Static contact angle results showed a significant increment of 49.8° and 53.4° for the respective surface hydrophobicity and lipophilicity measurements. More importantly, both storage modulus (G’) and loss modulus (G’’) are improved in the hybrid POSS PUs and these parameters can be further adjusted by varying POSS content in the copolymer. As a biodegradable hybrid filler, the as-synthesized POSS PUs also demonstrated a remarkable effect in toughening commercial polyesters, indicating a simple yet useful strategy in developing high-performance polyester for advanced biomedical applications.Keywords:bi-functional POSS;hydrophobic modification;thermoplastic polyurethane;mechanical performance
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2021
·Vol. 13
·期 20
·3489
·
IF 4.329
Yashu He,Jingting Wang,Igor S. Sirotin,Vyacheslav V. Kireev,Jianxin Mu
This study reports on a series of crosslinked poly(arylene ether)s with POSS in the main chain. The fluorinated and terminated poly(arylene ether)s were first synthesized by the nucleophilic reaction of diphenol POSS and decafluorodiphenyl monomers, including decafluorobiphenyl, decaflurobenzophenone, and decafluorodiphenyl sulfone. They were then reacted with 3-hydroxyphenyl acetylene to produce phenylacetylene-terminated poly(arylene ether)s. The polymers were of excellent processability. When heated to a high temperature, the polymers converted into a crosslinked network, exhibiting a low range of dielectric constant from 2.17 to 2.58 at 1 HMz, strong resistance against chemical solutions, low dielectric losses, and good thermal and hydrophobic properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2025
·Vol. 32
·期 4
·1-11
·
IF 2.8
Qiu Caihong,Liao Xiafeng,Zheng Yiru,zhang Haowen,Lu Zhen,Hou Linxi
To address the challenge of controllable and precise regulation of the phase behavior of block copolymers, this study proposes a novel strategy to regulate the self-organization behavior of PS-P2VP block copolymers through supramolecular self-assembly. PS-P2VP was synthesized via the RAFT method, and three POSS molecules with different non-covalent interactions were synthesized and used to form complexes with the PS-P2VP copolymers. Characterization techniques such as NMR, GPC, FT-IR, TGA, DSC, SAXS, and SEM, along with theoretical methods, were employed to analyze the impact of POSS on the phase behavior of PS-P2VP. The results demonstrate that POSS is particularly effective in modulating the self-assembled phase behavior in the lamellar phase of block copolymers, with BPOSS-Cl showing the most significant modulation, enabling the complexes to achieve third-order peaks in SAXS measurements. This conclusion is further supported by theoretical calculations. The study not only reveals the mechanism by which POSS regulates the self-assembly behavior of PS-P2VP but also provides a promising direction for advancing autonomous phase selection in block copolymers.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF DENTISTRY
·
2024
·
IF 4.8
XuanMei Ai,ZhaoNan Liu,TianQi Wang,Qi Xie,WeiLi Xie
Introduction This study create a dental composite by hybirding polyhedral oligo-sesquioxide nano monomers and bioactive glass BG 45S5. Methods Make an experimental composite resin material with a 60 % filler content overall by substituting 20 % of the filler with BG 45S5. The experimental resins are grouped and named P0, P2, P4, P6 and P8 based on the reactive nanomonomer methacrylic acid-based multifaceted oligomeric sesquisiloxane (POSS) added by 2 %–8 % in the resin matrix portion of each group. Utilize a universal testing machine to analyze and compare the mechanical properties of these, then perform Fourier infrared spectrum analysis, double bond conversion analysis, and scanning electron microscope analysis. Based on this, after soaking the experimental materials artificial saliva solution or lactic acid solution for a while, the pH changes of the solution, the release of Ca 2+ and PO 4 3− ions, and the precipitation of apatite on the resin material's surface were tested and analyzed. Cell viability tests were used to assess sample cell viability and quantify the cytotoxicity of biological cells. The independent sample t-test was used to examine the group comparisons, and a difference was considered statistically significant at P <0.05. Results Outstanding mechanical and the double bond conversion are demonstrated by the nanocomposites when the POSS concentration hits 4 wt%. Agglomeration will cause the performance to deteriorate if the concentration beyond this threshold. In the P4 group, the double bond conversion, CS, and FS rose by a large margin, respectively, in comparison to the blank control group P0. Thankfully, the data demonstrate that adding POSS increases adhesive ability when compared to the blank group P0, however, there is no discernible difference between the other experimental groups. The acid neutralization capacity of the P4 group is essentially the same as that of the control group (P0). Ca 2+ and PO 4 3− ions are released in significant amounts following treatment with lactic acid solution, although this tendency is clearly less pronounced in artificial saliva. SEM and EDX data indicate that when the experimental resin is soaked in lactic acid solution and artificial saliva, apatite precipitation will happen on its surface. The results of the cell viability test indicated that there was no statistically significant difference between the experimental groups, and the viability of the cells increased after 24hours and 48 hours. Conclusions POSS was included into the composite resin along with 20% bioactive glass as a filler. When the proportion of POSS is less than 4%, the indices of composite resin materials rise in a dose-dependent way. When this value is surpassed, performance begins to deteriorate. The inclusion of POSS has no influence on the biological activity of the composites, which means that the hybrid composite resin is capable of acid neutralization, ion release, and apatite precipitation. Clinical Significance The experimental composite resin can be used as an intelligent material in clinical treatment. It has the clinical application potential of preventing demineralization of tooth hard tissue, promoting remineralization, and improving edge sealing through apatite precipitation.
研究领域:
牙科材料学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Bin Yu,Anthony Chun Yin Yuen,Xiaodong Xu,Zhen-Cheng Zhang,Wei Yang,Hongdian Lu,Bin Fei,Guan Heng Yeoh,Pingan Song,Hao Wang
High-performance MXene-based polymer nanocomposites are highly desirable for diverse industry applications due to their exceptional mechanical, thermal and other properties. Nevertheless, it remains an intractable challenge to create flame retardant polymer/MXene nanocomposites due to the difficulty to achieve uniform dispersion of MXenes. Here, we reported a facile strategy for the surface manipulation of two-dimensional titanium carbide nanosheets (Ti 3 C 2 T x ) with 3-aminopropylheptaisobutyl-polyhedral oligomeric silsesquioxane (AP-POSS) (POSS-Ti 3 C 2 T x ) through electrostatic interactions. The POSS-Ti 3 C 2 T x is steadily dispersed in many polar solvents. Upon incorporated into polystyrene (PS), the combined effect of AP-POSS and MXene makes the resultant PS nanocomposites exhibit significantly improved thermal and thermoxidative stability, e.g. 22 °C and 39 °C increases in the temperature at 5 wt% mass loss under nitrogen and air, respectively. Meanwhile, a 39.1 % reduction in the peak heat release rate, a respective 54.4 % and 35.6 % reduction in the peak CO production rate and the peak CO 2 production rate was achieved, which are superior to those of its own and previous counterparts. This outstanding fire safety is attributed to the combination of adsorption, catalytic and barrier effects of POSS-Ti 3 C 2 T x . Hence, as-designed functionalized MXenes can be effectively applied in PS to formulate multifunctional polymer nanocomposites attractive for wide potential applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 4
·462
·
IF 4.7
Junhua Chen,Zhenxian Wu,Qingwei Wang,Chuanghui Yang,Jinlian Chen,He Zhang,Yinping Wu,Dong-Yu Zhu,Xiangying Hao
Water-based chloroprene latex is a solvent-free, environmentally friendly adhesive. Currently, its market demand is growing rapidly. However, there are problems such as a lack of heat resistance and poor mechanical properties, which limit its application. The introduction of vinyl-POSS (OVS) into the resin structure can effectively improve the thermal stability of chloroprene adhesives. In this paper, modified waterborne chloroprene latex was prepared by copolymerization of methyl methacrylate and OVS with chloroprene latex. The results showed that vinyl-POSS was successfully grafted onto the main chain of the waterborne chloroprene latex, and the modified waterborne chloroprene latex had good storage stability. With the increase in vinyl-POSS, the tensile strength of the chloroprene latex firstly increased and then decreased, the tensile property (peel strength of 20.2 kgf) was maintained well at a high temperature (100 °C), and the thermal stability of the chloroprene latex was improved. When the addition amount was 4%, the comprehensive mechanical properties were their best. This study provides a new idea for the construction of a new and efficient waterborne chloroprene latex system and provides more fields for the practical application of waterborne chloroprene latex. This newly developed vinyl-POSS modified chloroprene latex has great application potential for use in home furniture, bags, and seat cushions.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）