Olefin Metathesis–Based Chemically Recyclable Polymers Enabled by a Fused-Ring Monomer

2020 ◽  
Author(s):  
Junpeng Wang ◽  
Devavrat Sathe ◽  
Junfeng Zhou ◽  
Hanlin Chen ◽  
Hsin-Wei Su ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Ring Opening ◽  
Strain Energy ◽  
Decomposition Temperature ◽  
Excellent Thermal Stability ◽  
Fused Ring ◽  
Promising Solution ◽  
Sustainable Materials ◽  
Tunable Mechanical Properties

Abstract A promising solution to address the challenges in plastics sustainability is to replace current polymers with chemically recyclable ones that can depolymerise into their constituent monomers for circular use of materials. Despite the progress, few depolymerisable polymers exhibit the excellent thermal stability and strong mechanical properties of traditional polymers. Here we report a series of chemically recyclable polymers that show excellent thermal stability (decomposition temperature > 370 ºC) and tunable mechanical properties. The polymers are formed via ring-opening metathesis polymerisation of cyclooctene with a trans-cyclobutane installed at the 5,6-positions. The additional ring converts the non-depolymerisable polycyclooctene into a depolymerisable polymer by reducing the ring strain energy in the monomer (from 8.2 kcal/mol in unsubstituted cyclooctene to 4.9 kcal/mol in the fused ring). The fused-ring monomer enables a broad scope of functionalities to be incorporated, providing access to chemically recyclable elastomers and plastics that show promise as next-generation sustainable materials.

scholarly journals Performance Evaluation of Cellulose Nanofiber with Residual Hemicellulose as a Nanofiller in Polypropylene-Based Nanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1064
Author(s):  
Mohd Nor Faiz Norrrahim ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Mohd Ali Hassan ◽  
Nor Azowa Ibrahim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Weight Loss ◽  
Tensile Strength ◽  
Performance Evaluation ◽  
Flexural Strength ◽  
Decomposition Temperature ◽  
Cellulose Nanofiber ◽  
Hemicellulose Removal ◽  
Reinforcement Material

Residual hemicellulose could enhance cellulose nanofiber (CNF) processing as it impedes the agglomeration of the nanocellulose fibrils and contributes to complete nanofibrillation within a shorter period of time. Its effect on CNF performance as a reinforcement material is unclear, and hence this study seeks to evaluate the performance of CNF in the presence of amorphous hemicellulose as a reinforcement material in a polypropylene (PP) nanocomposite. Two types of CNF were prepared: SHS-CNF, which contained about 11% hemicellulose, and KOH-CNF, with complete hemicellulose removal. Mechanical properties of the PP/SHS-CNF and PP/KOH-CNF showed an almost similar increment in tensile strength (31% and 32%) and flexural strength (28% and 29%) when 3 wt.% of CNF was incorporated in PP, indicating that hemicellulose in SHS-CNF did not affect the mechanical properties of the PP nanocomposite. The crystallinity of both PP/SHS-CNF and PP/KOH-CNF nanocomposites showed an almost similar value at 55–56%. A slight decrement in thermal stability was seen, whereby the decomposition temperature at 10% weight loss (Td10%) of PP/SHS-CNF was 6 °C lower at 381 °C compared to 387 °C for PP/KOH-CNF, which can be explained by the degradation of thermally unstable hemicellulose. The results from this study showed that the presence of some portion of hemicellulose in CNF did not affect the CNF properties, suggesting that complete hemicellulose removal may not be necessary for the preparation of CNF to be used as a reinforcement material in nanocomposites. This will lead to less harsh pretreatment for CNF preparation and, hence, a more sustainable nanocomposite can be produced.

scholarly journals Structure and Properties of Polyoxymethylene/Silver/Maleic Anhydride-Grafted Polyolefin Elastomer Ternary Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1954
Author(s):  
Yang Liu ◽  
Xun Zhang ◽  
Quanxin Gao ◽  
Hongliang Huang ◽  
Yongli Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Maleic Anhydride ◽  
Ag Nanoparticles ◽  
Decomposition Temperature ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Maximum Value ◽  
Polyolefin Elastomer ◽  
Local Defects

In the present study, silver (Ag) nanoparticles and maleic anhydride-grafted polyolefin elastomer (MAH-g-POE) were used as enhancement additives to improve the performance of the polyoxymethylene (POM) homopolymer. Specifically, the POM/Ag/MAH-g-POE ternary nanocomposites with varying Ag nanoparticles and MAH-g-POE contents were prepared by a melt mixing method. The effects of the additives on the microstructure, thermal stability, crystallization behavior, mechanical properties, and dynamic mechanical thermal properties of the ternary nanocomposites were studied. It was found that the MAH-g-POE played a role in the bridging of the Ag nanoparticles and POM matrix and improved the interfacial adhesion between the Ag nanoparticles and POM matrix, owing to the good compatibility between Ag/MAH-g-POE and the POM matrix. Moreover, it was found that the combined addition of Ag nanoparticles and MAH-g-POE significantly enhanced the thermal stability, crystallization properties, and mechanical properties of the POM/Ag/MAH-g-POE ternary nanocomposites. When the Ag/MAH-g-POE content was 1 wt.%, the tensile strength reached the maximum value of 54.78 MPa. In addition, when the Ag/MAH-g-POE content increased to 15wt.%, the elongation at break reached the maximum value of 64.02%. However, when the Ag/MAH-g-POE content further increased to 20 wt.%, the elongation at break decreased again, which could be attributed to the aggregation of excessive Ag nanoparticles forming local defects in the POM/Ag/MAH-g-POE ternary nanocomposites. Furthermore, when the Ag/MAH-g-POE content was 20 wt.%, the maximum decomposition temperature of POM/Ag/MAH-g-POE ternary nanocomposites was 398.22 °C, which was 71.39 °C higher than that of pure POM. However, compared with POM, the storage modulus of POM/Ag/MAH-g-POE ternary nanocomposites decreased with the Ag/MAH-g-POE content, because the MAH-g-POE elastomer could reduce the rigidity of POM.

Effect of Long-Term Aging on Microstructure and Mechanical Properties of a Wrought Ni-Base Superalloy

2015 ◽  
Vol 816 ◽  
pp. 546-550
Author(s):  
Chao Yuan ◽  
Huan Wang ◽  
Jian Ting Guo ◽  
He Yong Qin
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Room Temperature ◽  
Excellent Thermal Stability ◽  
Good Thermal Stability ◽  
Increasing Trend ◽  
Size And Morphology ◽  
Strength And Plasticity ◽  
Base Superalloy

During long-term and high temperature service, microstructures of superalloys may change and then have an adverse impact on mechanical properties, so the stabilities of a wrought Ni-base superalloy aging without stress at 650°C were investigated in this paper. The results showed that the size and morphology of γ' precipitates in the alloy were not obviously influenced with the increase of exposure time, and primary MC carbides present excellent thermal stability. Moreover, almost no detrimental phase was found. Tensile strength and plasticity at room temperature after aging remained steady. Under the condition of 650°C/823MPa, the stress ruptures life presented increasing trend overall and plasticity decreases slightly. In conclusion, the experiment alloy presents a good thermal stability at 650°C.

Preparation, Characterization and Application of Siloxane Succinate Fatliquor

2011 ◽  
Vol 233-235 ◽  
pp. 292-297 ◽  
Author(s):  
Tao Tao Qiang ◽  
Xiang Luo ◽  
Long Fang Ren ◽  
Xue Chuan Wang ◽  
Bao Yuan He
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Castor Oil ◽  
Ring Opening ◽  
Rapeseed Oil ◽  
Raw Materials ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
Dyeing Property ◽  
Ring Opening Reaction

The silicone succinate surfactant (PMPS) was synthesized by ring-opening reaction using polyether alcohol amine modified polysilosane (PAPS) with maleic anhydride (MA) as the raw materials, and p-toluenesulfonic acid (PTSA) was used as the catalyst. Sulfated castor oil and sulfated rapeseed oil were combinated with PMPS to prepare a new leather fatliqour (PMPSF) composed mainly of PMPS. The molecular structure of PMPS was characterized by FTIR spectra; the thermal properties of PMPS was characterized and analyzed by TGA. PMPSF was used in sheepskin wet blue leather and compared with oxidative sulfited vegetable oils (L-3) and RF-1 fatliquor; the waterproof and mechanical properties of the leather were measured. The results show that the thermal decomposition temperature of PMPS is 192.8°C. Fatliquor PMPSF provids a good level-dyeing property, the leather oiled by it has good flexibility and fullness, the waterproofness and mechanical properties of leather are also good. Moreover, compared with the leather fatliquored by L-3, the thickening rate of leather oiled by PMPSF reaches 13.7%.

Effect of silanized sisal fiber on thermo-mechanical properties of reinforced epoxy composites

2019 ◽  
Vol 54 (15) ◽  
pp. 2037-2050
Author(s):  
M Moeez Mughal ◽  
M Wasim Akhtar ◽  
M Moazam Baloch ◽  
Muddassir Ali Memon ◽  
Junaid Ali Syed ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Epoxy Composite ◽  
Decomposition Temperature ◽  
Sisal Fiber ◽  
Stability Parameters ◽  
Molar Solution ◽  
Integral Procedure ◽  
Thermal Stability Parameters ◽  
Kinetics Of

An effective method was adopted to improve the thermo-mechanical properties of the epoxy composite by functionalization of the sisal fiber. Initially, a neat sisal fiber was acetylated with molar solution of acidic mixture (0.5:1 of HNO3:H2SO4) that removed the content of lignin and hemicellulose and increased the crystallinity of the sisal fiber. The acetylated sisal ( a-sisal) fiber was further treated with 3-aminpropyltriethoxy silane to graft the silanol moieties on sisal fiber. The functionalization of the sisal fiber with 3-aminpropyltriethoxy silane exhibits the strong interaction with epoxy, resulting in homogenous dispersion of the sisal fiber in epoxy. The composite possesses great enhancement in thermal and mechanical properties. The tensile strength in functionalized sisal epoxy composite ( CP-f-Sisal) was significantly enhanced up to 23% in comparison to non-functionalized sisal epoxy composite ( CP-n-Sisal) by adding 15 wt.% of the sisal fiber. In addition, the functionalized sisal epoxy composite ( CP-f-sisal) shows better thermal stability as compared to non-functionalized sisal epoxy composite ( CP-n-sisal). Similar results are attributed by investigating the kinetics of thermal stability parameters that include activation energy and integral procedure decomposition temperature.

scholarly journals Enhanced strength of nano-polycrystalline diamond by introducing boron carbide interlayers at the grain boundaries

2020 ◽  
Vol 2 (2) ◽  
pp. 691-698 ◽  
Author(s):  
Bo Zhao ◽  
Shengya Zhang ◽  
Shuai Duan ◽  
Jingyan Song ◽  
Xiangjun Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Boron Carbide ◽  
Grain Boundaries ◽  
Materials Science ◽  
Polycrystalline Diamond ◽  
Excellent Thermal Stability

Polycrystalline diamond with high mechanical properties and excellent thermal stability plays an important role in industry and materials science.

scholarly journals Promotion of poly(vinylidene fluoride) on thermal stability and rheological property of ethylene-tetrafluoroethylene copolymer

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 541-549 ◽  
Author(s):  
Jing Qian ◽  
Chao Fu ◽  
Xianyou Wu ◽  
Xianghai Ran ◽  
Wei Nie
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Vinylidene Fluoride ◽  
Decomposition Temperature ◽  
Application Area ◽  
Thermal Decomposition Temperature ◽  
Rheological Measurements ◽  
Maximum Decomposition Rate ◽  
Poly Vinylidene Fluoride ◽  
Ethylene Tetrafluoroethylene

AbstractIn this work, the thermal stability, rheological properties and mechanical properties of ethylene-tetrafluoroethylene copolymer (ETFE)/poly(vinylidene fluoride) (PVDF) blends were investigated by thermogravimetric analysis, rheometer and the tensile test. Thermal results indicated that blends had better thermal oxidation resistance than pure ETFE. Particularly, the initial thermal decomposition temperature (Td0) and the temperature at maximum decomposition rate (Tdmax) of PVDF/ETFE (10/90 wt%) blends were at 374.49°C and 480°C, which were 52.6°C and 34°C higher than pure ETFE. The activation energy of thermal degradation (Ed) of ETFE was 66 kJ/mol, while the PVDF/ETFE (10/90 wt%) blends presented a higher Ed, near 187 kJ/mol. Furthermore, rheological measurements demonstrated that the shear-thinning tendency of blends became stronger with increasing PVDF content. PVDF/ETFE (10/90 wt%) blends had somewhat lower mechanical properties than ETFE, which was still high enough for various applications. Blends with PVDF provided an efficient method to extend the application area of ETFE.

Research on Preparation, Properties and UV Curing Behaviors of Novel Myrcene-Based Vinyl Ester Resin

2013 ◽  
Vol 807-809 ◽  
pp. 2826-2830 ◽  
Author(s):  
Xue Juan Yang ◽  
Shou Hai Li ◽  
Xiao Dong Tang ◽  
Jian Ling Xia
Keyword(s):  
Thermal Stability ◽  
Vinyl Ester ◽  
Impact Resistance ◽  
Uv Curing ◽  
High Hardness ◽  
Decomposition Temperature ◽  
Ftir Analysis ◽  
Vinyl Ester Resin ◽  
Initial Decomposition Temperature ◽  
Excellent Thermal Stability

Myrcene-based vinyl ester resin (VER) monomer was prepared via simple Diels-Alder reaction and ring-opening esterification. The molecular structure and UV curing behaviors of prepared VER monomer were characterized using FTIR analysis method. Moreover, the mechanical properties, thermal stability and hardness of its UV cured product were also investigated. FTIR analysis results demonstrated that the target myrcene-based VER monomer has been successfully synthesized. UV curing behaviors analysis showed that prepared myrcene-based VER monomer could reach ultimate cured level within 50 s. Physical properties study showed that the UV cured product has certain tensile, flexural, impact resistance properties and high hardness. TGA indicated the UV cured product had excellent thermal stability, as it showed high thermal initial decomposition temperature at 359.6 °C .

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