Synthesis and Characterization of Poly (ε-caprolactone)/ TiO2 Nanocomposites Obtained by In Situ Polymerization

2011 ◽  
Vol 328-330 ◽  
pp. 1533-1536
Author(s):  
Guang Shuo Wang ◽  
Zhi Yong Wei ◽  
Lian Liu ◽  
Pei Wang ◽  
Min Qi

The novel biodegradable poly (ε-caprolactone)/TiO2 nanocomposites were prepared by in situ polymerization of ε-caprolactone in the presence of modified-TiO2 nanoparticles as initiator. The molecular weight of poly (ε-caprolactone) (PCL) matrix was dependent on the amount of the TiO2 fillers. The incorporation of TiO2 did not significantly affect the crystalline structure of PCL. An astounding nucleating effect of TiO2 on PCL crystallization was observed. The enhanced thermal stability of PCL nanocomposites was observed. The novel biodegradable poly (ε-caprolactone)/TiO2 nanocomposites were prepared by in situ polymerization of ε-caprolactone in the presence of modified-TiO2 nanoparticles as initiator. The molecular weight of poly (ε-caprolactone) (PCL) matrix was dependent on the amount of the TiO2 fillers. The incorporation of TiO2 did not significantly affect the crystalline structure of PCL. An astounding nucleating effect of TiO2 on PCL crystallization was observed. The enhanced thermal stability of PCL nanocomposites was observed.

2012 ◽  
Vol 182-183 ◽  
pp. 194-197
Author(s):  
Lian Liu ◽  
Yuan Liu ◽  
Teng Yu ◽  
Li Na Heng ◽  
Pei Wang

The novel biodegradable poly(ε-caprolactone)/TiO2nanocomposite materials were successfully prepared via in situ in the presence of modified-TiO2initiator and Sn(Oct)2 catalyst. The relationships between morphology, molecular weight, and properties were investigated by means of SEM, TGA, DSC and GPC. A tendency of the nanoparticles to form aggregates was observed, especially at higher fillers contents. The molecular weight of PCL matrix was dependent on the amount of the TiO2fillers


2011 ◽  
Vol 197-198 ◽  
pp. 606-609 ◽  
Author(s):  
Ti Feng Jiao ◽  
Yuan Yuan Xing ◽  
Jing Xin Zhou ◽  
Wei Wang

Some functional luminol derivatives with aromatic substituted groups have been designed and synthesized from the reaction of the corresponding aromatic acyl chloride precursors with luminol. It has been found that depending on the size of aromatic groups, the formed luminol derivatives showed different properties, indicating distinct regulation of molecular skeletons. UV and IR data confirmed commonly the formation of imide group as well as aromatic segment in molecular structures. Thermal analysis showed that the thermal stability of luminol derivatives with p-phthaloyl segment was the highest in those derivatives. The difference of thermal stability is mainly attributed to the formation of imide group and aromatic substituent groups in molecular structure. The present results have demonstrated that the special properties of luminol derivatives can be turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in functional material field and ECL sensor.


2012 ◽  
Vol 560-561 ◽  
pp. 174-178
Author(s):  
Yan Zou ◽  
Hui Min Qi ◽  
Mei Ling Xu ◽  
Fa Rong Huang ◽  
Lei Du

Hyperbranched poly(diethynylbenzene-silane) (hb-PDEBS) was synthesized through polycondensation reaction of diethynylbenzene Grignard reagent (A2) and trichlorosilane (B3), and its structure was characterized by FT-IR, 1H-NMR, GPC and Elemental Analysis. The degree of branching of hb-PDEBS was defined by 29Si-NMR and calculated to be about 0.68. The curing behavior of hb-PDEBS was investigated by DSC. Thermal stability of cured hb-PDEBS was examined by TGA, and its residue at 1000°C under nitrogen was 80.6%. Hb-PDEBS displayed a strong absorption due to π-π* transition and exhibited the most intensity structured emission with a maximum around 500 nm.


2013 ◽  
Vol 750-752 ◽  
pp. 1271-1275 ◽  
Author(s):  
Lian Hai Shan ◽  
Yuan Yuan Cui ◽  
Shuai Huang ◽  
Zhi Bin Zhang

The present study describes degradable polyurethane (PU) microspheres fabricated using toluene diisocyanate, polycaprolactone, polyethylene glycol, 2, 2-hydroxymethyl-2-propionic acid and triethylamine for drug delivery. The novel microspheres were synthesized using self-emulsion and condensed phase separation method. Fourier-Transform Infrared Spectrum analysis (FTIR) was performed revealing the chemical structure of polyurethane microspheres with special chains changing. Swelling properties influenced by solvent polarity, PEG content, PEG molecular weight, were evaluated, suggesting that the swelling ratio (SR) of PU microspheres increased with the increase in solvent polarity, PEG content and PEG molecular weight respectively.


2011 ◽  
Vol 675-677 ◽  
pp. 295-298
Author(s):  
Liang Shao ◽  
Jian Hui Qiu ◽  
Ming Zhu Liu ◽  
Hui Xia Feng ◽  
Guo Hong Zhang ◽  
...  

New types of conducting composites using andalusite as an inorganic substrate and polyaniline as the conducting phase were prepared. The composites exhibited conductivities in the 0.14-2.08 S/cm range, depending on the amount of polyaniline. The thermal stability of andalusite/polyaniline composites were studied by thermogravimetric analysis. The resulting composites were also characterized by using FTIR spectroscopy and scanning electron microscopy.


2010 ◽  
Vol 75 (4) ◽  
pp. 497-504 ◽  
Author(s):  
Fariasa de ◽  
Claudio Airoldib

In this paper, the synthesis and characterization of a GO-hmta compound (GO = graphite oxide; hmta = hexamethylenetetramine) are presented. It is shown that the presence of hmta molecules inside the GO matrix, with very strong interactions, stabilize the GO matrix from a thermal point of view. Such a fact could be used to explore possible applications of GO matrix, especially in catalysis.


BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 2492-2503
Author(s):  
Nour-Eddine El Mansouri ◽  
Qiaolong Yuan ◽  
Farong Huang

Epoxidization is an interesting way to develop a new application of lignin and therefore to improve its application potential. In this work, kraft lignin-based epoxy resins were obtained by the epoxidization reaction, using the kraft lignin recovered directly from pulping liquor and modified by a methylolation reaction. The methylolated lignins were obtained by the reaction of original kraft lignin with formaldehyde and glyoxal, which is a less volatile and less toxic aldehyde. 1H-NMR spectroscopy showed that methylolated kraft lignin has more hydroxymethyl groups than glyoxalated kraft lignin. For the epoxidization reaction we studied the influence of the lignin:NaOH (w/w) ratio, temperature, and time of the reaction on the properties of the prepared epoxidized lignins. The structures of lignin-based epoxy resins were followed by epoxy index test and FTIR spectroscopy. Optimal conditions were obtained for lignin-based epoxy resin produced at lignin/NaOH = 1/3 at 70 ºC for 3h. Thermogravimetry analysis (TGA) revealed that the epoxidization enhances the thermal stability of lignins and may allow a wider temperature range for applications with lignin epoxy-PF blends.


e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Aurica Farcas ◽  
Valeria Harabagiu

AbstractThis paper is devoted to the preparation and characterization of new phenanthroline-triether copolymers with rotaxane architecture by reaction of complexes of α- or β- cyclodextrin and tri(ethylene glycol) ditosylate with 2,9-di(4-hydroxyphenyl)-1,10- phenanthroline, which is large enough to prevent dethreading of cyclodextrin molecules. Comparative 1H-NMR analysis of tri(ethylene glycol) ditosylate complexes and of rotaxane copolymers evidenced the lower cyclodextrin content in rotaxane copolymers as compared to the calculated values. The rotaxane copolymers present bimodal molecular weight distributions attributed to the separation of the fractions with different content of cyclodextrin threaded on the copolymer chain. As evidenced by thermogravimetric analysis, the rotaxane copolymers show higher thermal stability than its non-complexed homologue.


2014 ◽  
Vol 904 ◽  
pp. 7-9
Author(s):  
Xiao Hua Gu ◽  
Xi Wei Zhang ◽  
Bao Yun Xu ◽  
Peng Zeng

In this paper, the diphenyl methane diisocyanate (MDI) was used to modify montmorillonoid (MMT) and got the organic montmorillonite (OMMT), which was used with the monomers of PET by in situ polymerization method to prepare PET/MMT nanocomposition. The OMMT was analyzed by the X ray diffraction (XRD) to test the change of the spacing layer. Dispersion of MMT in the PET/MMT nanocomposites were studied with XRD and SEM and by means of thermogravimetric analyzer (TGA) on the thermal stability of PET/MMT nanocomposites. The results showed that, MDI modified MMT successfully, and the compatibility of MMT and PET was increased .


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