A novel fluoro-terminated hyperbranched poly(phenylene oxide) (FHPPO): synthesis, characterization, and application in low-k epoxy materials

Luo, Lijuan; Qiu, Teng; Meng, Yan; Guo, Longhai; Yang, Jing; Li, Zhuoxin; Cao, Xingzhong; Li, Xiaoyü

doi:10.1039/c3ra40721g

Cited by 31 publications

(26 citation statements)

References 51 publications

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“…The higher free volumes for lignin–COOH@epoxy, which are reflected from their increases in Δα, may be the result of the integration of hyperbranched and rigid lignin into the epoxy. The similar phenomena were reported when other hyperbranched polymers was introduced into epoxy …”

Section: Resultssupporting

confidence: 84%

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

Sun

Wang

Stubbs

et al. 2017

Macro Materials & Eng

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The reactive phenolic and aliphatic hydroxyl groups in lignin facilitate its chemical modification to yield either epoxy monomers or curing agents (hardeners). Epoxy monomers from lignin could be obtained via epoxidation reaction between hydroxyl groups of lignin and epichlorohydrin or diglycidyl ether, and organosolv lignin or partially depolymerized lignin were exploited for their better solubility in organic solvent or higher hydroxyl content. [3] On the other hand, lignin-based hardeners were also designed and synthesized, and they could potentially reduce or eliminate the current usage of the toxic amine curing agents. [4] Although the pristine phenolic groups on lignin could react readily with epoxy monomers, carboxylic acid or amino groups are commonly introduced into lignin molecules to improve their miscibility with epoxy monomers. Especially, the carboxyl acid-functionalized lignin has been given much attentions. [5] The carboxylated lignin could be synthesized either via oxidation of aromatic ring by ozone in the presence of sodium hydroxide, or by esterification reaction of hydroxyl groups in lignin with anhydrides.Although the utilization of lignin as a comonomer or cocuring agent in epoxy has been attempted, it has often been reported that either the mechanical properties of resultant lignin epoxy composites at high lignin content were unsatisfactory or the mechanical properties were enhanced only when lignin acts as an additive at very low content, commonly less than 2 wt%. It is still a challenge to improve the mechanical properties by using lignin as an alternative hardener at high content. In this paper, the simultaneous strength reinforcement and toughness enhancement by employing carboxylated lignin as a cohardener at moderate content (10.0 wt %) is reported. We first modified pristine lignin with carboxylic acid groups by reacting it with succinic anhydride. In comparison with the pristine lignin, the resultant carboxylic acid-functionalized lignin (lignin-COOH) shows much better solubility in tetrahydrofuran (THF). It was mixed with epoxy monomer and amine hardener with aid of THF and then cured after removal of the solvent. The improved mechanical properties of the resulting composites should be ascribed to homogeneous dispersion of lignin-COOH within epoxy matrix, rigid structure of phenolic fragments in lignin, and the reduced crosslink density in the epoxy lignin composites. BiopolymersIt is demonstrated that pristine or functionalized lignin can be used in epoxy as a cohardener or comonomer; however either unsatisfactory mechanical properties or low lignin content remains a challenge in utilizing the sustainable biomass to replace petrochemical product. In this study, carboxylic acid-modified kraft lignin (lignin-COOH) is synthesized and used as a cohardener for epoxy with loading content of up to 10.0 wt%. With incorporation of 10.0 wt% of lignin-COOH, the resulting composite exhibits increments of 16%, 13%, 20%, and 95% on tensile modulus, flexural modulus, tensile strength, and tou...

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Section: Resultssupporting

confidence: 84%

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

Sun

Wang

Stubbs

et al. 2017

Macro Materials & Eng

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“…This phenomenon has also been observed by other researchers. [31][32][33][34] Because of the long aliphatic chains of CTMA, external stresses can be redistributed, and plastic deformations will be induced by the exible cross-linker. This is the reason why the fracture surfaces become rougher.…”

Section: Morphology Of the Fractured Surfacesmentioning

confidence: 99%

A renewable tung oil-derived nitrile rubber and its potential use in epoxy-toughening modifiers

Xiao

Liu

et al. 2019

RSC Adv.

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“…However, in these works, hyperbranched modifiers suffer from tediousness stepwise and higher cost, leading to difficulty in a large scale industrial application . In fact, a lot of papers are available in the literature, which describes the various synthetic approaches for the preparation of HBPSi using catalytic hydrosilylation, esterification, hydrolysis of siloxanes, reversible‐deactivation radical polymerization (RDRP), and proton transfer reactions (PTR) . However, these synthetic techniques suffer from different drawbacks.…”

Section: Introductionmentioning

confidence: 99%

OH‐ and NH₂‐Terminated Hyperbranched Polysiloxanes: Controlled Synthesis, Characterization, Toughening, and Reinforcing Epoxy Resin

Chen

Zhang

Cui

et al. 2018

Macro Chemistry & Physics

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A new silicon-containing hyperbranched polysiloxane (HAHBPs) is successfully synthesized via a one-pot A 2 + B 3 strategy using diethylene glycol and (3-aminopropyl)triethoxysilane (KH550) under solvent-free and catalystfree conditions. Then, for the first time, the HAHBPs are used to modify epoxy resin E51. TGA results display significantly lower thermal stability compared with that of the neat epoxy resin. Experimental results also show that the addition of HAHBPs simultaneously improves flexural strength and impact strength. In particular, a great increase (2.48 times its original toughness) in the toughness of epoxy resin E51 is achieved with 20 wt% HAHBPs loading. More importantly, fracture morphology and DMA measurements show no obvious phase separation due to the strong interfacial bonds between the HAHBPs and epoxy matrix. These results indicate that the HAHBPs containing OH-and NH 2 -can be a potentially effective epoxy resin toughener. Synthesis of OH-and NH 2 -Terminated Hyperbranched PolysiloxanesThe mole ratio of DEG/KH550 was 1.8 and that of -OH/-OC 2 H 5 was 1.2. The typical synthesis procedure of HAHBPs

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A novel fluoro-terminated hyperbranched poly(phenylene oxide) (FHPPO): synthesis, characterization, and application in low-k epoxy materials

Cited by 31 publications

References 51 publications

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

A renewable tung oil-derived nitrile rubber and its potential use in epoxy-toughening modifiers

OH‐ and NH₂‐Terminated Hyperbranched Polysiloxanes: Controlled Synthesis, Characterization, Toughening, and Reinforcing Epoxy Resin

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A novel fluoro-terminated hyperbranched poly(phenylene oxide) (FHPPO): synthesis, characterization, and application in low-k epoxy materials

Cited by 31 publications

References 51 publications

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

Carboxylated Lignin as an Effective Cohardener for Enhancing Strength and Toughness of Epoxy

A renewable tung oil-derived nitrile rubber and its potential use in epoxy-toughening modifiers

OH‐ and NH2‐Terminated Hyperbranched Polysiloxanes: Controlled Synthesis, Characterization, Toughening, and Reinforcing Epoxy Resin

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OH‐ and NH₂‐Terminated Hyperbranched Polysiloxanes: Controlled Synthesis, Characterization, Toughening, and Reinforcing Epoxy Resin