scholarly journals Design, Preparation, and Evaluation of a Novel Elastomer with Bio-Based Diethyl Itaconate Aiming at High-Temperature Oil Resistance

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1897
Author(s):  
Hui Yang ◽  
Haijun Ji ◽  
Xinxin Zhou ◽  
Weiwei Lei ◽  
Liqun Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Butyl Acrylate ◽  
Glycidyl Methacrylate ◽  
Average Molecular Weight ◽  
Ethyl Acrylate ◽  
Number Average Molecular Weight ◽  
Elongation At Break ◽  
Oil Resistance ◽  
Monomer Ratio ◽  
Preparation And Evaluation

A novel elastomer poly(diethyl itaconate-co-butyl acrylate-co-ethyl acrylate-co-glycidyl methacrylate) (PDEBEG) was designed and synthesized by redox emulsion polymerization based on bio-based diethyl itaconate, butyl acrylate, ethyl acrylate, and glycidyl methacrylate. The PDEBEG has a number average molecular weight of more than 200,000 and the yield is up to 96%. It is easy to control the glass transition temperature of the PDEBEG, which is ranged from −25.2 to −0.8 °C, by adjusting the monomer ratio. We prepared PDEBEG/CB composites by mixing PDEBEG with carbon black N330 and studied the oil resistance of the composites. The results show that the tensile strength and the elongation at break of the composites with 10 wt% diethyl itaconate can reach up to 14.5 MPa and 305%, respectively. The mechanical properties and high-temperature oil resistance of the composites are superior to that of the commercially available acrylate rubber AR72LS.

High-Temperature Homopolymerization of Ethyl Acrylate andn-Butyl Acrylate:  Polymer Characterization

2005 ◽  
Vol 38 (18) ◽  
pp. 7619-7628 ◽  
Author(s):  
Congling Quan ◽  
Masoud Soroush ◽  
Michael C. Grady ◽  
Joan E. Hansen ◽  
William J. Simonsick
Keyword(s):  
High Temperature ◽  
Butyl Acrylate ◽  
Ethyl Acrylate ◽  
Polymer Characterization ◽  
Acrylate Polymer

scholarly journals Polar poly(n-butyl acrylate)-g-polyacrylonitrile elastomer with high temperature elasticity and healability as flexible electronic substrate

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuzhu Zheng ◽  
Deli Xu ◽  
Shiyou Tian ◽  
Manli Li ◽  
Wenwen Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Graft Copolymer ◽  
Butyl Acrylate ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Self Healing ◽  
Chemical Structures ◽  
Flexible Electronic ◽  
Ag Nanowires ◽  
Cyano Groups

AbstractIn this work, graft copolymer poly (n-butyl acrylate)-g-polyacrylonitrile with poly (n-butyl acrylate) as backbones and polyacrylonitrile as side chains (PnBA-g-PAN) was synthesized by macromonomer method and emulsion polymerization. The macromonomer was synthesized by atom transfer radical polymerization and end-group modification. The chemical structures and thermal properties of macromonomer and graft copolymer were investigated by FTIR, GPC, NMR and TGA, etc. The mechanical properties of graft copolymer elastomer was also measured by uniaxial tensile test. Rheological properties at different temperature and mechanical property demonstrated that graft copolymer elastomer possessed elasticity until 180 oC because of cyclization of cyano groups. Ag nanowires@PnBA-g-PAN composite elastomer was developed, and the resulted material exhibited autonomic healing property on account of segments’ flexibility and dynamic interaction between Ag nanowires (AgNWs) and cyano groups. This is a general method for generation of elastomer with high temperature elasticity and fast self-healing. The composite elastomer has potential application in flexible electronic conductor.

Some inequalities for moments and coefficients of variation for a large class of probability functions

1979 ◽  
Vol 16 (3) ◽  
pp. 665-670 ◽  
Author(s):  
Burt V. Bronk
Keyword(s):  
Large Class ◽  
Average Molecular Weight ◽  
Empirical Measure ◽  
Number Average Molecular Weight ◽  
Positive Real ◽  
Coefficients Of Variation ◽  
Probability Densities ◽  
Rigorous Bounds ◽  
Illustrative Application

Some inequalities for moments and coefficients of variation of probability densities over the positive real line are obtained by means of simple geometrical relationships. As an illustrative application rigorous bounds are obtained for the ratio of weight average to number average molecular weight for a large class of distributions of macromolecules, giving a more precise characterization of this empirical measure of heterogeneity.

Chemistry and Properties of Imide Oligomers from Phenylethynyl-Containing Diamines

2000 ◽  
Vol 12 (1) ◽  
pp. 213-223 ◽  
Author(s):  
J G Smith ◽  
J W Connell
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Research Effort ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Similar Composition ◽  
Imide Oligomers ◽  
Calculated Number

As an extension of work on pendent phenylethynyl-containing imide oligomers, three new diamines containing pendent phenylethynyl groups were prepared and characterized. These diamines were used to prepare pendent and pendent and terminal phenylethynyl imide oligomers via the amide acid route in N-methyl-2-pyrrolidinone at a calculated number average molecular weight of 5000 g mol−1. The pendent phenylethynyl groups were randomly distributed along the oligomer backbone and provided a means of controlling the distance between reactive sites. The imide oligomers were characterized and thermally cured, and the cured polymers evaluated as thin films and compared with materials of similar composition prepared from 3,5-diamino-4′-phenylethynylbenzophenone. This work was performed as part of a continuing research effort to develop structural resins for potential aeronautical applications.

Kinetic Studies on the Curing Reactions of Fluoroepoxy Oligomer and Cycloaliphatic Amine

2013 ◽  
Vol 747 ◽  
pp. 753-756 ◽  
Author(s):  
Thitinun Chongtum ◽  
Wunpen Chonkaew
Keyword(s):  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Kinetic Studies ◽  
Equivalent Weight ◽  
Number Average Molecular Weight ◽  
Polymeric Systems ◽  
Acid Titration ◽  
Curing Kinetic ◽  
Gel Permeation

The curing kinetic analysis is an important technique for the characterization of the curing behavior of reactive polymeric systems. In this study, fluoroepoxy oligomer was synthesized from trifluoromethyl aniline and epichlorohydrin. The epoxide equivalent weight (EEW) and the number average molecular weight (Mn) of the systhesized fluroepoxy oligomer determined from acid titration and gel permeation chromatography were found to be 312.16 g/eq and 534 g/mol, respectively. The mixtures of the fluoroepoxy oligomer were mixed with the cycloaliphatic amine in various stiochiometric ratios (1:1, 1: 1.5 and 1:2). The effects of the stiochiometric ratio on the curing behaviors were studied using both isothermal and non-isothermal DSC methods. Ozawas, Kissingers and Friedmans methods were employed to investigate the kinetic parameters. The results showed that the peak temperature (Tp) increased with the increasing heating rate. The activation energy (Ea) calculated from Ozawas and Kissingers methods were much larger than that from Friedmans method.

scholarly journals Crystallization, Structure and Significantly Improved Mechanical Properties of PLA/PPC Blends Compatibilized with PLA-PPC Copolymers Produced by Reactions Initiated with TBT or TDI

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3245
Author(s):  
Lixin Song ◽  
Yongchao Li ◽  
Xiangyu Meng ◽  
Ting Wang ◽  
Ying Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Average Molecular Weight ◽  
Toluene Diisocyanate ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Cooling Process ◽  
Material Degradation ◽  
Elongation At Break ◽  
Poly Propylene

Poly (lactic acid) (PLA)-Poly (propylene carbonate) (PPC) block copolymer compatibilizers are produced in incompatible 70wt%PLA/PPC blend by initiating transesterification with addition of 1% of tetra butyl titanate (TBT) or by chain extension with addition of 2% of 2,4-toluene diisocyanate (TDI). The above blends can have much better mechanical properties than the blend without TBT and TDI. The elongation at break is dramatically larger (114% with 2% of TDI and 60% with 1% of TBT) than the blend without TDI and TBT, with a slightly lower mechanical strength. A small fraction of the copolymer is likely formed in the PLA/PPC blend with addition of TBT, and a significant amount of the copolymer can be made with addition of TDI. The copolymer produced with TDI has PPC as a major content (~70 wt%) and forms a miscible interphase with its own Tg. The crystallinity of the blend with TDI is significantly lower than the blend without TDI, as the PLA blocks of the copolymer in the interphase is hardly to crystallize. The average molecular weight increases significantly with addition of TDI, likely compensating the lower mechanical strength due to lower crystallinity. Material degradation can occur with addition of TBT, but it is very limited with 1% of TBT. However, compared with the blends without TBT, the PLA crystallinity of the blend with 1%TBT increases sharply during the cooling process, which likely compensates the loss of mechanical strength due to the slightly material degradation. The added TDI does not have any significant impact on PLA lamellar packing, but the addition of TBT can make PLA lamellar packing much less ordered, presumably resulted from much smaller PPC domains formed in the blend due to better compatibility.

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