Preparation and characterization of polylactic acid-g-bamboo fiber based on in-situ solid phase polymerization

2018 ◽  
Vol 123 ◽  
pp. 646-653 ◽  
Author(s):  
Yingfeng Zuo ◽  
Wenhao Li ◽  
Ping Li ◽  
Wenjie Liu ◽  
Xingong Li ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Solid Phase ◽  
Bamboo Fiber

Study on the compatible interface of bamboo fiber/polylactic acid composites by in-situ solid phase grafting

2019 ◽  
Vol 141 ◽  
pp. 325-332 ◽  
Author(s):  
Wenhao Li ◽  
Xiaoyu He ◽  
Yingfeng Zuo ◽  
Shu Wang ◽  
Yiqiang Wu
Keyword(s):  
Polylactic Acid ◽  
Solid Phase ◽  
Bamboo Fiber

Study on the Synthesis and Characterization of PANi/Nano-CeO2 Composites

2007 ◽  
Vol 124-126 ◽  
pp. 287-290 ◽  
Author(s):  
Fei Liu ◽  
Yong Jun He ◽  
Jeung Soo Huh
Keyword(s):  
In Situ Polymerization ◽  
Solid Phase ◽  
Polymerization Reaction ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Average Size

The nano-CeO2 was synthesized by two-step solid-phase reaction. The image of TEM showed that nano-CeO2 with an average size of about 70 nm. The series of polyaniline/nano-CeO2 composites with different PANi: CeO2 ratios were prepared by in-situ polymerization in the presence of hydrochloric acid (HCl) as dopant by adding nano-CeO2 into the polymerization reaction mixture of aniline. The composites obtained were characterized by FT-IR and UV-vis spectroscopy analysis. The FT-IR spectra of nanocomposites indicate different blue-shifts, attributed to C–N stretching mode for benzenoid unit. The UV-vis spectra of nanocomposites display einstein-shifts compared with PANi at 620nm. The conductivity properties of the composites are also changed compare to the pure PANi. These results suggest that the interactions between the polymer matrix and nanoparticles take place in polyaniline/nano- CeO2 composites.

scholarly journals In-situ characterization of growth of isothermal ω phase in metastable β-Ti alloy TIMETAL LCB

2020 ◽  
Vol 321 ◽  
pp. 11037
Author(s):  
J. Nejezchlebova ◽  
L. Bodnarova ◽  
M. Janovska ◽  
P. Sedlak ◽  
H. Seiner ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Elastic Constants ◽  
Elastic Anisotropy ◽  
Solid Phase ◽  
In Situ Observation ◽  
Ω Phase ◽  
Resonant Ultrasound ◽  
Isothermal Ageing

Metastable β-Ti alloys exhibit various solid-solid phase transitions. Our study is focused on the characterization of the diffusion controlled β→ωiso phase transition. The particles of ω phase play an important part in thermomechanical treatment since they serve as heterogeneous nucleation sites for precipitation of finely dispersed particles of hexagonal α phase. The in-situ observation of the growth of particles of ω phase could be difficult by conventional techniques. However, it was shown recently that the ω phase significantly influences the elastic constants of the material, and the different forms of ω phase have different effects on the elastic anisotropy, as well as on the internal friction coefficients. Therefore, the β→ω phase transformation could be in-situ observed by the precise measurement of the tensor of elastic constants. In this contribution, we present the study of the kinetics of the β→ωiso phase transformation by resonant ultrasound spectroscopy. The polycrystalline samples of TIMETAL LCB alloy were in-situ examined by this technique during isothermal and non-isothermal ageing at temperatures up to 300 °C.

Structural Characterization of Ion Beam Enhanced Solid Phase Epitaxial Regrowth by Raman, RBS, and X-Ray Analysis

1988 ◽  
Vol 126 ◽  
Author(s):  
John F. Knudsen ◽  
R. C. Bowman ◽  
P. M. Adams ◽  
R. Newman ◽  
J. P. Hurrell ◽  
...  
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Beam Current ◽  
Crystalline Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Epitaxial Regrowth ◽  
High Beam Current

ABSTRACTEpitaxial regrowth of deposited amorphous silicon has been previously described utilizing ion implantation amorphization, ion mixing and thermal anneal. This paper evaluates the effects of these process steps on crystalline quality utilizing Rutherford Backscattering (RBS), x-ray diffraction rocking curves and Raman scattering.In situ (during implantation) regrowth results in defective crystallinity. In contrast, when there is no in situ regrowth, the post anneal crystallinity is equivalent by RBS and x-ray evaluation to virgin single crystal wafers. In situ regrowth is most pronounced during the high beam current ion mixing type implants which produce wafer temperatures of about 250°C. The final crystalline quality which results from different sequences of amorphization and ion mixing implants, is strongly dependent upon the amount of in situ regrowth which has occurred. The greater the in situ regrowth the poorer the final crystalline quality.

Preparation and Characterization of Three-Element Compound Plasticizing Bamboo Fiber-g-Polylactic Acid/Polylactic Acid Composite

2019 ◽  
Vol 956 ◽  
pp. 201-211 ◽  
Author(s):  
Wen Hao Li ◽  
Xiao Yu He ◽  
Shu Wang ◽  
Bing Jie Xu ◽  
Yi Qiang Wu ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Interfacial Adhesion ◽  
Water Resistance ◽  
Bamboo Fiber ◽  
National Standards ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
X Ray ◽  
Interfacial Compatibility

In view of the phenomenon that the interfacial adhesion between bamboo fiber（BF）and polylactic acid (PLA) is poor and incompatible. Firstly the BF-g-PLA structure with hydrophobicity is synthesized through grafting lactic acid into bamboo fiber, then plasticizing the composite. Three-element compound plasticizer was prepared by mixing glycerol, tributyl citrate and formamide. The effect of the proportion and addition content of three-element plasticizer on the interfacial compatibility of the composite was investigated. The BF-g-PLA/PLA composites were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and rotational rheometer (RC) The composites were tested for their bending properties, tensile properties and water resistance properties using national standards. The experimental results show that the best interfacial adhesion between BF-g-PLA and PLA was obtained when the addition content of glycerol, tributyl citrate, formamide was 10%. At the same time, the flexural strength, elastic modulus, tensile strength and elongation at break of composites all reached the maximum, as well as the thermal stability and the storage modulus.

scholarly journals Preparation and Characterization of Hydrophobically Grafted Starches by In Situ Solid Phase Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 72 ◽  
Author(s):  
Yingfeng Zuo ◽  
Xiaoyu He ◽  
Ping Li ◽  
Wenhao Li ◽  
Yiqiang Wu
Keyword(s):  
Molecular Weight ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Graft Polymer ◽  
X Ray ◽  
Grafting Reaction ◽  
Grafting Ratio ◽  
Ft Ir

Three kinds of hydrophobic groups grafted starches of maleic anhydride grafted starch (MAH-g-starch), lactic acid grafted starch (LA-g-starch), and methyl acrylate grafted starch (MA-g-starch) were prepared by in situ solid phase polymerization. The results of Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) confirmed successful grafting. The grafting ratios of MAH-g-starch, LA-g-starch, and MA-g-starch were 6.50%, 12.45%, and 0.57%, respectively. Influenced by the grafting ratio, LA-g-starch had the best relative hydrophobicity and the largest molecular weight, and those for MA-g-starch were the worst. The surfaces of grafted starches were covered with graft polymer, with obvious surface roughness and bond degree of MAH-g-starch and LA-g-starch. The crystalline structure of grafted starches showed some damage, with LA-g-starch exhibiting the greatest decrease in crystallinity, and less of a change for MA-g-starch. Overall, the grafting reaction improved thermoplasticity, with LA-g-starch the most improved, followed by MAH-g-starch, and then MA-g-starch.

scholarly journals Preparation and Characterization of Hydrophobic Groups Grafted Starches by In-Situ Solid Phase Polymerization

2018 ◽  
Author(s):  
Yinfeng Zuo ◽  
Xiaoyu He ◽  
Ping Li ◽  
Wenhao Li ◽  
Yiqiang Wu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Graft Polymer ◽  
Hydrophobic Properties ◽  
X Ray ◽  
Grafting Reaction ◽  
Grafting Ratio ◽  
Ft Ir

Three kinds of hydrophobic groups grafted starches of maleic anhydride grafted starch (MAH-g-starch), lactic acid grafted starch (LA-g-starch), and methyl acrylate grafted starch (MA-g-starch) were prepared by in-situ solid phase polymerization. The results of Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were confirmed successful grafting. The grafting ratios of MAH-g-starch, LA-g-starch and MA-g-starch were 6.50%, 12.45%, and 0.57%, respectively. Influenced by the grafting ratio, LA-g-starch had the best hydrophobic properties and the largest molecular weight, and those for MA-g-starch was the worst. The surfaces of grafted starches were covered with graft polymer, with obvious surface roughness and bond degree of MAH-g-starch and LA-g-starch. The crystalline structure of grafted starches showed some damage, with LA-g-starch exhibiting the greatest decrease in crystallinity, and less of a change for MA-g-starch. Overall, the grafting reaction improved thermoplasticity, with LA-g-starch the most improved, followed by MAH-g-starch, and then MA-g-starch.

In Situ Optical Analysis of Structural Changes in Polylactic Acid (PLA) during the Gas Dissolution Process

2014 ◽  
Vol 353 ◽  
pp. 131-136
Author(s):  
B. Notario ◽  
Javier Pinto ◽  
E. Solórzano ◽  
J. Escudero ◽  
J. Martín de León ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Structural Changes ◽  
Crystallization Process ◽  
Optical Measurements ◽  
Optical Parameters ◽  
Whole Process ◽  
Complex Phenomena ◽  
Non Destructive

An own-designed pressure vessel with glass windows has been employed to perform an in-situ characterization of the temporal evolution of the crystallization process of an amorphous polylactic acid (PLA) under different controlled CO2 pressures and temperatures. It has been proven that crystallinity can be related to optical parameters such as transmissivity, obtaining information about the whole process by optical measurements. The method has the advantage of measuring in-situ over bulk samples with a non-destructive tool. The obtained results have shown some unexpected trends that have been explained taking into account the complex phenomena occurring during the crystallization process of PLA in the presence of CO2 at high pressure.

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