scholarly journals Enzymatic Degradation of Acrylic Acid-Grafted Poly(butylene succinate-co-terephthalate) Nanocomposites Fabricated Using Heat Pressing and Freeze-Drying Techniques

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 376 ◽  
Author(s):  
Sheng-Hsiang Lin ◽  
Hsiang-Ting Wang ◽  
Jie-Mao Wang ◽  
Tzong-Ming Wu
Keyword(s):  
Acrylic Acid ◽  
Freeze Drying ◽  
Crystallization Rate ◽  
X Ray Diffraction ◽  
Butylene Succinate ◽  
Covalent Bonds ◽  
Polymer Backbone ◽  
Transmission Electron ◽  
Degradation Rates ◽  
Organically Modified

Biodegradable acrylic acid-grafted poly(butylene succinate-co-terephthalate) (g-PBST)/organically modified layered zinc phenylphosphonate (m-PPZn) nanocomposites were effectively fabricated containing covalent bonds between the g-PBST and m-PPZn. The results of wide-angle X-ray diffraction and transmission electron microscopy revealed that the morphology of the g-PBST/m-PPZn nanocomposites contained a mixture of partially exfoliated or intercalated conformations. The isothermal crystallization behavior of the nanocomposites showed that the half-time for crystallization of 5 wt % g-PBST/m-PPZn nanocomposites was less than 1 wt % g-PBST/m-PPZn nanocomposites. This finding reveals that increasing the loading of m-PPZn can increase the crystallization rate of nanocomposites. Degradation tests of g-PBST/m-PPZn nanocomposites fabricated using the heat pressing and the freeze-drying process were performed by lipase from Pseudomonas sp. The degradation rates of g-PBST-50/m-PPZn nanocomposites were significantly lower than those of g-PBST-70/m-PPZn nanocomposites. The g-PBST-50 degraded more slowly due to the higher quantity of aromatic group and increased stiffness of the polymer backbone. The degradation rate of the freeze-drying specimens contained a more extremely porous conformation compared to those fabricated using the heat pressing process.

Millable Polyurethane/Organoclay Nanocomposites: Preparation, Characterization, and Properties

2007 ◽  
Vol 7 (2) ◽  
pp. 634-640 ◽  
Author(s):  
M. Siliani ◽  
M. A. López-Manchado ◽  
J. L. Valentín ◽  
M. Arroyo ◽  
A. Marcos ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Substantial Improvement ◽  
Nanometer Scale ◽  
X Ray Diffraction ◽  
Transformation Techniques ◽  
Covalent Bonds ◽  
X Ray ◽  
Transmission Electron ◽  
Organically Modified ◽  
Diffraction Patterns

Novel millable polyurethane (PU)/organoclay nanocomposites have been successfully prepared by conventional transformation techniques. One natural (C6A) and two organically modified (C15A and C30B) montmorillonites have been used as clays for preparing PU nanocomposites. The optimum dispersion of nanofiller at a nanometer scale in PU matrix was confirmed by X-ray diffraction patterns and transmission electron microscopy. A substantial improvement of the PU properties by addition of only a small amount of organoclay was observed. It is worthy to note that the organoclays show a different interfacial interaction with the PU matrix, which was reflected in different macroscopic properties. Thus, C30B organoclay seems to react with PU chains to form covalent bonds, while C15Aonly interacts physically with PU chains. Mechanical and barrier properties are analyzed.

scholarly journals Melt Processing and Characterization of Biodegradable Poly(butylene succinate-co-adipate)/Hexadecylamine-Modified Layered Zinc Phenylphosphonate Nanocomposites

2018 ◽  
Author(s):  
Dong-Lin Kuo ◽  
Erh-Chiang Chen ◽  
Tzong-Ming Wu
Keyword(s):  
Isothermal Crystallization ◽  
Average Molecular Weight ◽  
Crystallization Rate ◽  
Melt Processing ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
Butylene Succinate ◽  
Transmission Electron ◽  
Biodegradable Poly

Biocompatible and biodegradable poly(butylene succinate-co-adipate) (PBSA)/hexadecylamine-modified PPZn (m-PPZn) nanocomposites were prepared using a melt mixing process. Experimental results of wide-angle X-ray diffraction and transmission electron microscopy revealed that the stacking layers of the m-PPZn were partially intercalated and partially exfoliated into the PBSA polymer matrix. The isothermal crystallization kinetics of PBSA/m-PPZn nanocomposites were studied at the temperature range of 62−70 °C and the half-time for crystallization of 3 wt % PBSA/m-PPZn nanocomposite was reduced by 27−35% compared with that of pure PBSA. This finding suggests that the incorporation of m-PPZn might cause the heterogeneous nucleation and the subsequent crystallization growth, which enhances the isothermal crystallization rate of PBSA/m-PPZn nanocomposite. The biodegradation rates of PBSA using Lipase from Pseudomonas sp. increase as the contents of m-PPZn increase. The degradation behavior of the neat PBSA investigated using the change of weight-average molecular weight belongs to exo-type hydrolysis activity. It is necessary to point out that the change of degree of crystallinity and degradation rate are almost linearly proportional to the loading of hexadecylamine-modified PPZn. This finding would provide an important information for the manufacturing biodegradable PBSA nanocomposites.

scholarly journals Synthesis, Physical Properties and Enzymatic Degradation of Biodegradable Nanocomposites Fabricated Using Poly(Butylene Carbonate-Co-Terephthalate) and Organically Modified Layered Zinc Phenylphosphonate

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2149
Author(s):  
Li-Ying Tseng ◽  
Erh-Chiang Chen ◽  
Jie-Mao Wang ◽  
Tzong-Ming Wu
Keyword(s):  
Nmr Spectra ◽  
Enzymatic Degradation ◽  
Molar Ratio ◽  
Wide Angle ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Organically Modified ◽  
Biodegradable Nanocomposites

A new biodegradable aliphatic-aromatic poly (butylene carbonate-co-terephthalate) (PBCT-85) with the molar ratio [BC]/[BT] = 85/15, successfully synthesized through transesterification and polycondensation processes, was identified using 1H-NMR spectra. Various weight ratios of PBCT/organically modified layered zinc phenylphosphonate (m-PPZn) nanocomposites were manufactured using the solution mixing process. Wide-angle X-ray diffraction and transmission electron microscopy were used to examine the morphology of PBCT-85/m-PPZn nanocomposites. Both results exhibited that the stacking layers of m-PPZn were intercalated into the PBCT-85 polymer matrix. The additional m-PPZn into PBCT-85 copolymer matrix significantly enhanced the storage modulus at −70 °C, as compared to that of neat PBCT-85. The lipase from Pseudomonas sp. was used to investigate the enzymatic degradation of PBCT-85/m-PPZn nanocomposites. The weight loss decreased as the loading of m-PPZn increased, indicating that the existence of m-PPZn inhibits the degradation of the PBCT-85 copolymers. This result might be attributed to the higher degree of contact angle for PBCT-85/m-PPZn nanocomposites. The PBCT-85/m-PPZn composites approved by MTT assay are appropriate for cell growth and might have potential in the application of biomedical materials.

Morphology, mechanical, and thermal properties of aramid/layered silicate nanocomposite materials

2008 ◽  
Vol 23 (9) ◽  
pp. 2296-2304 ◽  
Author(s):  
Sonia Zulfiqar ◽  
Muhammad Ilyas Sarwar ◽  
Ingo Lieberwirth ◽  
Zahoor Ahmad
Keyword(s):  
Water Uptake ◽  
Layered Silicate ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
Solution Intercalation ◽  
Dimethyl Acetamide ◽  
Transmission Electron ◽  
Organically Modified ◽  
Two Phases

Aramid-based nanocomposites were prepared by solution intercalation techniques using p-aminobenzoic acid-modified montmorillonite. Polyamide was synthesized by reacting 4,4′-oxydianiline with isophthaloyl chloride in dimethyl acetamide. To create chemical interactions between the two phases for better dispersion of organoclay, aramid chains were selectively amine end-capped. The influence of organically modified clay on the morphology was investigated by x-ray diffraction (XRD), polarized optical microscopy (POM), and transmission electron microscopy (TEM). Mechanical, thermal, and water uptake measurements were carried out to further verify other physical properties of the nanocomposites. Tensile strength, modulus, elongation at break, and toughness were improved relative to pure polymer with the addition of 6 wt% organoclay. Thermal-decomposition temperatures of the nanocomposites were in the range 300–450 °C. Water uptake of neat aramid film was rather high (5.7%) and decreased with augmenting organoclay. DSC exhibited increase in the glass transition temperature (118 °C) up to addition of 16 wt% of organoclay.

Preparation and Properties of Nanocomposites Based on Poly(Vinyl acetate) and Montmorillonite Organized with Acrylic Acid

2011 ◽  
Vol 335-336 ◽  
pp. 3-11
Author(s):  
Jun Wang
Keyword(s):  
Acrylic Acid ◽  
Vinyl Acetate ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
Emulsion Copolymerization ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Ft Ir ◽  
Vinyl Group

The nanocomposites of poly(vinyl acetate)/montmorillonite (PVAc/MMT) were prepared using vinyl acetate and organically modified alkaline calcium base montmorillonite (MMT) by in situ emulsion copolymerization. The organic modification was acrylic acid including terminal reactive vinylic group. The samples were characterized using fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD). Thermal properties of the PVAc/MMT films were studied by thermogravimetric (TG) and differential scanning calorimetric (DSC). The FT-IR results indicated that the vinyl group on the surface of the vinyl MMT nanoparticles had been successfully copolymerized with vinyl acetate. The XRD results demonstrated that the MMT was exfoliated during polymerization. The exfoliated PVAc/MMT nanocomposites showed a lower glass transition temperature (Tg) and a worse thermal stability compared with the pure PVAc. However, bonding power of the nanocomposite latex of PVAc/MMT was improved due to the strong interaction between silica nanoparticles and polymer matrix via covalent bonds.

scholarly journals Synthesis and physical properties of biodegradable nanocomposites fabricated using acrylic acid-grafted poly(butylene carbonate-co-terephthalate) and organically-modified layered zinc phenylphosphonate

2021 ◽  
Author(s):  
Yi-Fang Lee ◽  
Tzong-Ming Wu
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Covalent Bond ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Nuclear Magnetic Resonance Spectra ◽  
Organically Modified ◽  
Biodegradable Nanocomposites

Abstract A set of novel biocompatible aliphatic-aromatic nanocomposites, including numerous acrylic acid-grafted poly(butylene carbonate-co-terephthalate) (g-PBCT) and organically-modified layered zinc phenylphosphonate (m-PPZn), were successfully synthesized via polycondensation and transesterification. A primary covalent linkage was produced between the biocompatible polymer and the inorganic reinforcements. Fourier transform infrared spectroscopy and 13C-nuclear magnetic resonance spectra demonstrated the successful grafting of acrylic acid into the PBCT (g-PBCT). Both wide-angle X-ray diffraction data and X-ray photoelectron spectroscopy analysis showed that the g-PBCT polymer matrix was intercalated into the interlayer spacing of the m-PPZn and was chemically interacted with the m-PPZn. The addition of m-PPZn in the g-PBCT matrix significantly improved its storage modulus. A slight increase in thermal stability was observed in all the g-PBCT/m-PPZn composites. Both results are attributed to the presence of covalent bond between g-PBCT and m-PPZn.

scholarly journals FABRICATION OF Fe3O4 MAGNETIC FLUID BY POLY (ACRYLIC ACID) FOR BIOMEDICAL APPLICATIONS

2018 ◽  
Vol 54 (1A) ◽  
pp. 261 ◽  
Author(s):  
Vuong Thi Kim Oanh
Keyword(s):  
Acrylic Acid ◽  
Saturation Magnetization ◽  
Magnetic Fluid ◽  
Fe3o4 Nanoparticles ◽  
Phase Transfer ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Average Size ◽  
Poly Acrylic Acid

Fe3O4 nanosystems of different sizes were synthesized by thermal decomposition method in organic solvent. Magnetic fluid based on Fe3O4 nanoparticles was prepared by using poly acrylic acid (PAA) as a phase transfer agent. The structure, morphology and magnetic properties of samples were studied by: X-ray diffraction patterns (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM). XRD results indicated that all samples had spinel single phase structure with average crystaline size less than 15 nm. TEM images showed that the average size of samples were nearly equal to those of XRD. The highest value of saturation magnetization obtained at room temperature for the sample synthesized at optimal reaction time and temperature (2 hours and 298 oC, respectively) after phase transferring was 75 emu/g. The linkage between magnetic nanoparticles’ surface and functional groups of PAA was confirmed by FT-IR spectra. Simultaneously, the particle size and stability of magnetic fluid were evaluated by DLS and Zeta potential. These results demonstrated the narrow size distribution and high stability of nanosystem. The important point was that the phase transfer contributed to enhance of saturation magnetization of samples (about 5 % of the initial ones). Magnetic fluid based on Fe3O4 nanoparticles with high homogeneity, high saturation magnetization and good stability promised a potential application in biomedical, especially in magnetic hyperthermia and contrast-enhanced magnetic resonance imaging.

Effect of the organic groups of difunctional silanes on the preparation of coated clays for olefin polymer modification

Clay Minerals ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 489-502 ◽  
Author(s):  
F. E. Monasterio ◽  
M. L. Dias ◽  
V. J. R. R. Pita ◽  
E. Erdmann ◽  
H. A. Destéfanis
Keyword(s):  
Condensation Polymerization ◽  
Polymer Modification ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Organically Modified ◽  
Structural Differences ◽  
Intercalated Nanocomposite ◽  
Clay Materials ◽  
Thermal Stability Of

AbstractSodium montmorillonite (MMT) was organically modified with hexadecyltrimethyl-ammonium ions and subsequently treated with dichlorosilanes and water, aimed at in situ silane condensation polymerization and modification of clay platelets by polysiloxane coatings. Dimethyldichlorosilane, methylphenyldichlorosilane, and diphenyldichlorosilane were used to produce three siloxane-modified organoclays. The structure and morphology of the clay materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric studies (TG) and scanning electron microscopy (SEM). XRD results showed that the silanes were effectively polymerized in the clay galleries, forming a nanocomposite of intercalated particles. A fraction of the siloxane formed is bonded to the clay surface by covalent siloxane bonds. Strong structural differences in both morphology and thermal stability of the materials may occur when changing methyl or phenyl groups in the siloxane structure. The formation mechanism of these intercalated nanocomposite particles is considered. Finally, these modified clays were incorporated in an olefin polymer and morphological analyses using transmission electron microscope (TEM) images were carried out.

Effect on Flame Retardancy and Mechanical Properties of PA6 Nanocomposites with Addition of OMMT and PFR

2013 ◽  
Vol 712-715 ◽  
pp. 195-198
Author(s):  
Dong Mei Bao ◽  
Ji Ping Liu ◽  
Xiang Yang Hao
Keyword(s):  
Mechanical Properties ◽  
Flame Retardancy ◽  
Flexural Modulus ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
Transmission Electron ◽  
Nanocomposite System ◽  
Organically Modified ◽  
Twin Screw

The organically modified montmorrillonite (OMMT)/phosphorus polymeic flame retardant (PFR)/polyamide 6(PA6) nanocomposites were prepared via melt intercalation on a twin-screw extruder. The structure formed in nanocomposite system was investigated by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). Properties such as flame retardancy, notched impact strength, tensile strength, elongation at break and flexural modulus were studied by limited oxygen index (LOI) approach, UL94, and mechanical property test. The results of the studies indicated that flame retardancy and mechanical properties of PA6 nanocomposites were all reinforced due to addition of OMMT and PFR.

scholarly journals Influence of Nanoparticle Pretreatment on the Thermal, Rheological and Mechanical Properties of PLA-PBSA Nanocomposites Incorporating Cellulose Nanocrystals or Montmorillonite

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Wissam Abdallah ◽  
Amin Mirzadeh ◽  
Victor Tan ◽  
Musa Kamal
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanocrystals ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Butylene Succinate ◽  
Freeze Dried ◽  
Organically Modified ◽  
Spray Freeze Drying ◽  
Adsorption Desorption ◽  
Quaternary Ammonium Chloride

Nanoparticles based on cellulose nanocrystals (CNC) and montmorillonite clay (MMT) were prepared using spray freeze-drying. The nanoparticles were then used as reinforcement to prepare nanocomposites with poly(lactic acid) (PLA) as the polymer matrix. The effect of spray freeze-dried CNC (SFD-CNC) and spray freeze-dried MMT (SFD-MMT) on the rheological and mechanical properties of PLA and its blends with poly[(butylene succinate)-co-adipate)] (PBSA) were investigated. An epoxy chain extender was used during preparation of the blends and nanocomposites to enhance the mechanical properties of the products. Different methods such as scanning electron microscopy, X-ray diffraction and adsorption/desorption analyses were used to characterize the prepared nanoparticles and their localization in the blends. Dynamic oscillatory shear behavior, elongational viscosity and mechanical characteristics of the nanocomposites of PLA and the blends were evaluated. The results obtained for nanocomposites filled with unmodified SFD-MMT were compared with those obtained when the filler was a commercial organically modified montmorillonite nanoclay (methyl-tallow-bis(2-hydroxyeethyl) quaternary ammonium chloride) (C30B), which was not spray freeze-dried.

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