Chemical modification of banana starch by the in situ polymerization of ϵ-caprolactone in one step

2016 ◽  
Vol 69 (5-6) ◽  
pp. 1600197 ◽  
Author(s):  
Aurelio Ramírez-Hernández ◽  
Alejandro Aparicio-Saguilán ◽  
José L. Mata-Mata ◽  
Gerardo González-García ◽  
Héctor Hernández-Mendoza ◽  
...  
2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
M. A. Domínguez-Crespo ◽  
A. B. López-Oyama ◽  
A. M. Torres-Huerta ◽  
A. R. Hernández-Basilio ◽  
D. Palma-Ramírez ◽  
...  

In this work, hybrid composites were prepared using polyaniline (PANI) and electrochemically reduced graphene oxide (ERGO) by in situ polymerization. ERGO powders were obtained by a two-way route, Hummer’s method, and one-step potential (−2 V) followed by annealing process at 400°C (TERGO powders): different quantities of TERGO fine particles (10, 20, and 30 wt%) were added to the in situ PANI polymerization in order to produce the hybrid composites. The morphology and structure of the PANI/TERGO compounds were characterized by Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermal treatment of ERGO powders pointed out high-defect surfaces with a wrinkle-type morphology (ID/IG ratio~0.90). The emeraldine phase of PANI was obtained with a maximum value of 61%, which decreases with the amount of TERGO powders. It is also seen that composites displayed a combined morphology between PANI matrix and TERGO powders, confirming a physical interaction between both morphologies. The amount of TERGO particles into the polymeric matrix also modifies the sample microstructure from a semispherical shape to extend sheets, where PANI is sandwiched between TERGO layers. Electrical conductivity of composites slightly increases independent of the TERGO amount (30 S/m and 39 S/m) due to the rough TERGO surface that conditioned the homogeneous nucleation of a large amount of polymer (PANI) reducing the area to move the electrical charge.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1651 ◽  
Author(s):  
Saisai Huang ◽  
Qiufang Jiang ◽  
Bin Yu ◽  
Yujing Nie ◽  
Zhongqing Ma ◽  
...  

Acetylation and in situ polymerization are two typical chemical modifications that are used to improve the dimensional stability of bamboo. In this work, the combination of chemical modification of vinyl acetate (VA) acetylation and methyl methacrylate (MMA) in situ polymerization of bamboo was employed. Performances of the treated bamboo were evaluated in terms of dimensional stability, wettability, thermal stability, chemical structure, and dynamic mechanical properties. Results show that the performances (dimensional stability, thermal stability, and wettability) of bamboo that was prepared via the combined pretreatment of VA and MMA (VA/MMA-B) were better than those of raw bamboo, VA single-treated bamboo (VA-B), and MMA single-treated bamboo (MMA-B). According to scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses, VA and MMA were mainly grafted onto the surface of the cell wall or in the bamboo cell lumen. The antiswelling efficiency and contact angle of VA/MMA-B increased to maximum values of 40.71% and 107.1°, respectively. From thermogravimetric analysis (TG/DTG curves), the highest onset decomposition temperature (277 °C) was observed in VA/MMA-B. From DMA analysis, the storage modulus (E’) of VA/MMA-B increased sharply from 15,057 Pa (untreated bamboo) to 17,909 Pa (single-treated bamboo), and the glass transition temperature was improved from 180 °C (raw bamboo) to 205 °C (single-treated bamboo).


2010 ◽  
Vol 178 ◽  
pp. 236-241
Author(s):  
Jing Xie ◽  
Shang Yue Shen ◽  
Yu Xia Luo ◽  
Meng Meng Zhang ◽  
Ying Chen

Epoxy resin/ montmorillonite (EP/MMT) composite was prepared via monomer insert in-situ polymerization. It was shown that the EP/MMT composites could be successfully synthesized from the raw materials only by one step, making it simpler than traditional in-situ intercalative polymerization method. The d001 spacing of montmorillonite was tested by XRD and increased to 4.30nm. The results showed that tensile strength and impact strength were improved by 98.11 and 93.69%, respectively. The glass transition temperature was increased by 17.3 °C.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Weixing Xu ◽  
Jianfei Zhou ◽  
Ya’nan Wang ◽  
Bi Shi

Leather split, the byproduct of leather manufacture, possesses low utility value because it has loose weave of collagen fibers and weak mechanical strengths. Herein, a practical and convenient method for increasing strengths of leather split was developed by one-step in situ polymerization. The structures and properties of polyacrylate/leather split composites were systematically investigated. The results suggested the monomers with an α-methyl and a proper straight-chain ester group, such as nBMA, can effectively modify the leather split. For leather split with a thickness of 1.6 mm, the rational processes for preparation of polyacrylate/leather split composite are that monomer and split were stirred in a drum for 4 hours for full permeation and then the split was heated in anaerobic condition at 45°C for 30 min. The tensile strength, tear strength, and elongation at break of the optimized PnBMA/split composite were 18.72 MPa, 62.73 N/mm, and 46.02%, respectively. With these mechanical properties, the split after modification can be well used as leather for making shoes, bags, gloves, and clothing.


RSC Advances ◽  
2019 ◽  
Vol 9 (52) ◽  
pp. 30503-30508
Author(s):  
Jingxing Zhang ◽  
Zekun Guo ◽  
Yancong Feng ◽  
Yao Wang ◽  
Hao Li ◽  
...  

Liquid crystal (LC) smart windows with adjustable reflectivity have been gradually applied in green and intelligent building materials for energy saving needs, but their applications are limited by their fundamental defects.


2012 ◽  
Vol 531 ◽  
pp. 35-38 ◽  
Author(s):  
Hong Yu Mi ◽  
You Long Xu

Ternary composites of Ag–loaded polypyrrole/carbon nanotube (Ag–PPy/CNT) are prepared using a one–step in situ polymerization. Ag nanoparticles are uniformly decorated on the core–shell PPy/CNT networks. This approach provides a simple, easily accessible strategy for preparing three–dimensional noble metal–conductive polymer–carbon nanotube composites. Electrochemical properties of Ag–loaded composites are evaluated to understand the effect of Ag on the structure and kinetic process of the composite. Results indicate that the composites have good electrochemical reversibility and high specific capacitance. The specific capacitiance of Ag–PPy/CNT composites are enhanced greatly from 206.7 F g–1 of PPy/CNT composites to 528.6 F g–1 at 3 mA cm–2. This demonstrates that combining nano–sized Ag with supercapacitor materials is very effective in promoting electrochemical performance of materials.


RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 49448-49458 ◽  
Author(s):  
Jiaojiao Ma ◽  
Ying Li ◽  
Xiande Yin ◽  
Yu Xu ◽  
Jia Yue ◽  
...  

A novel and one-stepin situpolymerization method for preparing the poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposites.


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