Unique Gelation of Polyethylene Glycol-Modified Lignin in Hot Ethanol and Its Application to the Synthesis of Epoxy Resin with a Large Lignin Content

The effect of reactive (polyethylene glycol) and non-reactive (toluene) diluents on thermal and mechanical properties (tensile strength, hardness and fracture toughness) of diglycidyl ether of bisphenol A epoxy resin (cured by triethylenetetramine) was investigated. The thermal stability and mechanical properties of the epoxy resin modified with reactive and non-reactive diluents at different wt% were investigated using thermo-gravimetric analyser, tensile test, hardness test and single-edge-notched bend test. A minor variation in thermal stability was observed for epoxy resin after addition of polyethylene glycol and toluene at 0.5 wt%; however, further addition of reactive and non-reactive diluents diminished the thermal stability. The addition of 10 wt% of polyethylene glycol in epoxy resin significantly enhances the tensile strength (∼12%), hardness (∼14%) and fracture toughness (∼24%) when compared to that of neat epoxy resin. In contrast, major drop in mechanical performance was observed after addition of toluene in epoxy. Furthermore, fracture surfaces were investigated under field emission scanning electron microscope to elucidate the failure mechanism.

Download Full-text

Synthesis of Lignin-Based Epoxy Resin in Ionic Liquid [BMIm]Cl

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.740.51 ◽

2015 ◽

Vol 740 ◽

pp. 51-54

Author(s):

Wen Ting Li ◽

Ming Qiang Chen ◽

Zhong Lian Yang

Keyword(s):

Ionic Liquid ◽

Epoxy Resin ◽

Synthesis Temperature ◽

Raw Material ◽

Value Analysis ◽

Alkali Lignin ◽

Optimum Synthesis ◽

Ft Ir ◽

Modified Lignin ◽

Epoxy Value

Industrial alkali lignin (LG) was used as raw material and ionic liquid 1-butyl 3-methylimidazolium chloride ([BMIm]Cl) was used as solvent. Alkali lignin was dissolved into the [BMIm]Cl and modified as propyl ether lignin(HLG). Then the HLG modified lignin was used to synthesizing the lignin-based epoxy resin (LGEP) with epoxy chloropropane. The structure of LG, HLG and LGEP were characterized with FT-IR, the results indicated that the propyl group was introduced to the LG and the reaction activity was improved. The expoxy value analysis results showed that the optimum synthesis temperature was 80°C and the epoxy value was 0.218.

Download Full-text

Effect of Lignin Content on Properties of Flexible Transparent Poplar Veneer Fabricated by Impregnation with Epoxy Resin

Polymers ◽

10.3390/polym12112602 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2602 ◽

Cited By ~ 1

Author(s):

Mengting Lu ◽

Wen He ◽

Ze Li ◽

Han Qiang ◽

Jizhou Cao ◽

...

Keyword(s):

Thermal Stability ◽

Tensile Strength ◽

Optical Properties ◽

Solar Cells ◽

Thermogravimetric Analysis ◽

Epoxy Resin ◽

Lignin Content ◽

Light Transmittance ◽

Smart Windows ◽

Thermal Stability Of

In this work, poplar veneer (PV) rotary-cut from fast-growing polar was delignified to prepare flexible transparent poplar veneer (TPV). Lignin was gradually removed from the PV and then epoxy resin filled into the delignified PV. The study mainly concerns the effect of lignin content on microstructure, light transmittance, haze, tensile strength, and thermal stability of the PVs impregnated with epoxy resin. The results indicate that the lignin could be removed completely from the PV when the delignification time was around 8 h, which was proved by FTIR spectra and chemical component detection. Moreover, according to SEM observation and XRD testing, the porosity and crystallinity of the PVs were gradually increased with the removal of lignin. Also, the optical properties measurement indicated that the light transmittance and haze of the TPVs gradually increased, and the thermal stability also became more stable as shown by thermogravimetric analysis (TG). However, the tensile strength of the TPVs declined due to the removal of lignin. Among them, TPV8 exhibited excellent optical properties, thermal stability, and tensile strength. Consequently, it has great potential to be used as a substrate in photovoltaics, solar cells, smart windows, etc.

Download Full-text

Study on the Synthesis and Properties of EP/PU Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.221.135 ◽

2011 ◽

Vol 221 ◽

pp. 135-139 ◽

Cited By ~ 6

Author(s):

Xiao Qian Wang ◽

Zhi Xiong Huang ◽

Juan Li Zheng ◽

Qi Lin Mei

Keyword(s):

Mechanical Properties ◽

Polyethylene Glycol ◽

Epoxy Resin ◽

Ftir Spectrum ◽

Damping Properties ◽

Testing Frequency ◽

Higher Temperature

Isocyanate-terminated polyurethane was synthesized from polyethylene glycol and toluene disocyantes, which was used to modify the epoxy resin. D-230 was chosen as hardener to produce the PU/EP composite. The structure of composite was characterized by FTIR spectrum. Mechanical properties of the epoxy resin with different PU content were studied. Additionally, damping properties of the PU/EP composite were investigated using DMA, and the results showed that the damping properties of EP evidently improved by blending with PU and with the testing frequency increased, the spectra of tanδ-T shifted to higher temperature.

Download Full-text

Hot Solvent Extraction Method for Recycle Epoxy Resin in Waste Printed Circuit Board with Polyethylene Glycol

Materials Science Forum ◽

10.4028/www.scientific.net/msf.857.524 ◽

2016 ◽

Vol 857 ◽

pp. 524-529

Author(s):

Rapeeporn Srisuk ◽

Chaisiri Kitpaosong ◽

Suchart Siengchin ◽

Rapeephun Dangtungee

Keyword(s):

Polyethylene Glycol ◽

Epoxy Resin ◽

Extraction Method ◽

Printed Circuit Board ◽

Circuit Board ◽

Chemical Extraction ◽

Metal Part ◽

Printed Circuit ◽

Waste Printed Circuit Board ◽

Ft Ir

Waste printed circuit board (WPCB) from waste electrical and electronic equipment (e-waste) can be recycled a precious metal part while a non-metal part was burned or landfilled, which normally generated toxic substance of organic component to environment. The research work aimed to recycle epoxy resin by hot solvent chemical extraction. Polyethylene glycol 400 (PEG400) and ethylene glycol (EG), at 180°C, were mainly using as solvent and sodium hydroxide (NaOH) as a catalyst. Extraction method was reflux technique. The thermogravimetric analysis (TGA), Specific viscosity, and Fourier transform infrared spectroscopy (FT-IR) methods were investigated and discussed. The TGA result showed that the organic composition was 40.73%wt. The maximum of percent yield was 97.89% at non-metal WPCB/PEG, equal to 0.05 g/ml. Moreover, the extracted product presented a functional group close to virgin epoxy resin according to the peak of FT-IR data. The recycled epoxy resin could be formed well on specimen by virgin epoxy resin and hardener filled with 50% recycled extraction product.

Download Full-text

Chemical recycling of fiber-reinforced epoxy resin using a polyethylene glycol/NaOH system

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684414555745 ◽

2014 ◽

Vol 33 (22) ◽

pp. 2106-2114 ◽

Cited By ~ 16

Author(s):

Peng Yang ◽

Qian Zhou ◽

Xiao-Yang Li ◽

Ke-Ke Yang ◽

Yu-Zhong Wang

Keyword(s):

Polyethylene Glycol ◽

Glass Fiber ◽

Epoxy Resin ◽

Carbon Fibers ◽

Photoelectron Spectroscopy ◽

Glass Fibers ◽

Chemical Recycling ◽

X Ray ◽

Alkali Glass ◽

Original Strength

A polyethylene glycol/ NaOH system has been used for chemical recycling of fiber/epoxy resin composites. Solvolysis of the composites based on different fibers, i.e. two PAN-based carbon fibers (Torry T300, T700S) and two glass fibers (non-alkali glass fiber and medium-alkali glass fiber), have been compared. The solubilization degree increases with rising reaction temperature, reaction time, as well as NaOH amount. After reacting at atmospheric pressure for 4 h at 200℃ with 0.1 g NaOH/g composite, a high decomposition efficiency of 84.1–93.0% has been obtained. Scanning electron microscopy analysis shows that the two recovered carbon fibers and the non-alkali glass fiber have a texture similar to the as-received fibers, except that some residual resin adheres to the surface, while the medium-alkali glass fiber is damaged during recycling. Accordingly, the recycled carbon fibers and the non-alkali glass fiber retain 94–96% of their original strength, while the tensile strength of the recycled medium-alkali glass fiber decreases to below 90% of this value. The two carbon fibers were further characterized using X-ray photoelectron spectroscopy and X-ray diffraction. The carbon structure is slightly oxidized and the degree of graphitization of the recovered carbon fibers slightly decreases.

Download Full-text

Effect of high-temperature-resistant epoxy resin/polyethylene glycol 2000 composite stereotyped phase change material particles on asphalt properties

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.124007 ◽

2021 ◽

Vol 300 ◽

pp. 124007

Author(s):

Zhe Liu ◽

Kun Wei ◽

Sifan Wang ◽

Biao Ma ◽

Xiaoqing Wang ◽

...

Keyword(s):

Polyethylene Glycol ◽

High Temperature ◽

Phase Change ◽

Epoxy Resin ◽

Phase Change Material ◽

Change Material

Download Full-text

Preparation of Polyurethane-Modified Epoxy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.818 ◽

2012 ◽

Vol 550-553 ◽

pp. 818-821 ◽

Cited By ~ 1

Author(s):

Ya Ning Hao ◽

Cun Zhou ◽

Guo Zheng ◽

Yu Sun ◽

Jia Yin Li ◽

...

Keyword(s):

Polyethylene Glycol ◽

Ir Spectra ◽

Epoxy Resin ◽

Peg 400 ◽

Effects Of Temperature ◽

Modified Epoxy ◽

Unmodified Epoxy ◽

Polyurethane Prepolymer

Polyurethane (PU) prepolymer with the isocyanine-based were synthesized by toluene -2, 4-diisocyanate (TDI), polyethylene glycol (PEG-400) and polyethylene glycol (PEG-1000) with N-methylpyrrolidone as the solvent. The effects of temperature and time on the synthesis of polyurethane prepolymer were examined in this paper. The structures of PU, unmodified epoxy resin and modified epoxy resin were identified by FI-IR spectra. It was shown that polyurethane prepolymer was synthesized at 70°C for 5 hours and modified epoxy resin was synthesized successfully.

Download Full-text

Tunable Boc Modification of Lignin and Its Impact on Microbial Degradation Rate

10.26434/chemrxiv.7257212.v3 ◽

2021 ◽

Author(s):

Liuqun Gu ◽

Meifeng Wang ◽

Hui Li ◽

Kai Ni Teh ◽

Yiqun Li ◽

...

Keyword(s):

Lignin Content ◽

Aqueous Media ◽

System Thinking ◽

Sodium Lignosulfonate ◽

Breakdown Rate ◽

Covalent Bonds ◽

Random Match ◽

Polymeric Implants ◽

New Type ◽

Modified Lignin

A new type of modified lignin, lignin-p-Boc, was obtained through reaction with di-tert-butyl dicarbonate (Boc2O) in aqueous media catalyzed by 4-dimethylaminopyridine (DMAP). Boc modification occurred regardless of type of lignin, was tunable, and proceeded well in recovering lignin at high purity from sodium lignosulfonate (a common byproduct from pulping industry; lignin content: 60%). Lignin-p-BOC was demonstrated as a potential reactive filler in green plastic and as a potential crosslinker in design of bioresorbable composite polymeric implants. Furthermore, the effects of the modification on the breakdown rate of alkali lignin by microbes was investigated, and the results showed that the modification substantially decreases the breakdown rate. The tunable Boc modification process was designed via a system thinking, including availability of raw lignin, economical/green modification, potentiality of drop-in-change to current thermoplastic processing, modification impact on microbial degradability/disposed environment at the end of use life; hence the holistic consideration makes this alternative method for upgrade of technical lignins very practical for future industrial application. Via forming “easily breakable covalent bonds” with thermopolymers, Lignin-p-BOCs are also promising to play an important role as both excellent binders via “random match” and reductants in transforming linear plastic waste into circular plastics.

Download Full-text