scholarly journals Synthesis, Characterization and Properties of Biodegradable Poly(Butylene Sebacate-Co-terephthalate)

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2389 ◽  
Author(s):  
Sun Jong Kim ◽  
Hyo Won Kwak ◽  
Sangwoo Kwon ◽  
Hyunho Jang ◽  
Su-il Park
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sebacic Acid ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
Dimethyl Terephthalate ◽  
Biodegradable Poly ◽  
Ft Ir ◽  
Inherent Strength ◽  
The Fourier Transform

In this study, poly(butylene sebacate-co-terephthalate) (PBSeT) was successfully synthesized using various ratios of sebacic acid (Se) and dimethyl terephthalate (DMT). The synthesized PBSeT showed a high molecular weight (Mw, 88,700–154,900 g/mol) and good elastomeric properties. In particular, the PBSeT64 (6:4 sebacic acid/dimethyl terephthalate mole ratio) sample showed an elongation at break value of over 1600%. However, further increasing the DMT content decreased the elongation properties but increased the tensile strength due to the inherent strength of the aromatic unit. The melting point and crystallization temperature were difficult to observe in PBSeT64, indicating that an amorphous copolyester was formed at this mole ratio. Interestingly, wide angle X-ray diffraction (WAXD) curves was shown in the cases of PBSeT46 and PBSeT64, neither the crystal peaks of PBSe nor those of poly(butylene terephthalate) (PBT) are observed, that is, PBSeT64 showed an amorphous form with low crystallinity. The Fourier-transform infrared (FT-IR) spectrum showed C–H peaks at around 2900 cm−1 that reduced as the DMT ratio was increased. Nuclear magnetic resonance (NMR) showed well-resolved peaks split by coupling with the sebacate and DMT moieties. These results highlight that elastomeric PBSeT with high molecular weight could be synthesized by applying DMT monomer and showed promising mechanical properties.

scholarly journals Biodegradable Poly(butylene adipate-co-terephthalate) Antibacterial Nanocomposites Reinforced with MgO Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 507
Author(s):  
Xionggang Wang ◽  
Lingna Cui ◽  
Shuhong Fan ◽  
Xia Li ◽  
Yuejun Liu
Keyword(s):  
Antibacterial Properties ◽  
Inhibition Zone ◽  
Nucleating Agent ◽  
X Ray Diffraction ◽  
Mgo Nanoparticles ◽  
Elongation At Break ◽  
E Coli ◽  
Melt Compounding ◽  
Biodegradable Poly ◽  
Ft Ir

Antibacterial packaging materials can reduce the microbial contamination of food surfaces. In this study, magnesium oxide (MgO) nanoparticles were synthesized and then coated with cetrimonium bromide (CTAB). CTAB-modified MgO (MgO@CTAB) was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis. Then, different loadings of MgO@CTAB were mixed with poly(butylene adipate-co-terephthalate) (PBAT) by melt compounding. The results showed that the addition of MgO@CTAB deteriorated the thermal stability of PBAT due to MgO serving as a catalyst to promote the thermal degradation of PBAT. In addition, MgO@CTAB could serve as a nucleating agent to improve the crystallinity of PBAT. With the optimal 3 wt% of MgO@CTAB, the tensile strength of PBAT/MgO@CTAB increased from 26.66 to 29.90 MPa, with a slight enhancement in elongation at break. SEM observations and dynamical rheological measurements revealed that aggregation occurred when the content of MgO@CTAB exceeded 5 wt%. The presence of MgO@CTAB endowed PBAT with antibacterial properties. The bacterial inhibition zone increased with the increasing content of MgO@CTAB. In addition, MgO@CTAB had a better antibacterial efficiency against Gram-positive bacterial S. aureus than Gram-negative bacterial E. coli.

scholarly journals Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Polyurethane Foams ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Closed Cell ◽  
Ft Ir ◽  
The Fourier Transform

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

Synthesis of Cyclic Polysulfides and their Properties as Curing Agents

2004 ◽  
Vol 77 (2) ◽  
pp. 380-390
Author(s):  
Wonmun Choi ◽  
Tomoyuki Matsumura
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
High Molecular Weight ◽  
Mass Spectra ◽  
Elongation At Break ◽  
Molecular Weights ◽  
Aging Properties ◽  
Curing Agents ◽  
Polysulfide Polymer

Abstract The reactions of dichloroalkanes and sodium tetra-sulfide (Na2S4) were carried out in a mixture of water and toluene to produce corresponding cyclic polysulfides and polysulfide polymer. The low molecular weights of cyclic sulfides were obtained by the reaction at 90 °C, while the high molecular weight of polysulfide polymer was obtained by the reaction at 50 °C. GPC chromatograms and Mass spectra revealed that the structures of cyclic polysulfide were 1:1, 2:2, and 3:3 adducts of dichloroalkane and sodium tetra-sulfide. The mechanical properties of vulcanized NR at 148 °C with cyclic sulfides were similar to that with sulfur. However, both tensile strength and elongation at break of vulcanized NR at 170 °C with cyclic sulfides are much higher than that with sulfur. The aging properties of vulcanized NR at 148 °C or 170 °C with cyclic polysulfides indicate better stability.

Preparation and Properties Study on the Composites of Polypropylene and Polyphenylene Sulfide Filled by Modified Molybdenum Disulfide

2009 ◽  
Vol 87-88 ◽  
pp. 345-350
Author(s):  
Jian Qiang Zhang ◽  
Hui Xia Feng ◽  
Jian Hui Qiu
Keyword(s):  
Surface Modification ◽  
Molybdenum Disulfide ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Polyphenylene Sulfide ◽  
X Ray Diffraction ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
The Fourier Transform ◽  
Wear Modes

The wet surface modification process were used in this work to get the well lipophilic molybdenum disulfide (MoS2) powders and the modified MoS2 were filled into the polyphenylene sulfide (PPS) and polypropylene (PP) powders with different proportions to make polymeric based composites through hot-press molding equipment. The Fourier transform infrared spectrometer (FT-IR) analysis showed that the modification agents of stearic acid (SA), orγ-Methacryloxypropyl trimethoxy silane(KH570 or A-174), could react with the adsorption hydroxyl(−OH) of the MoS2 powders and finally form chemical coatings, the SA could form a layer of physics wrap too. The powder X-ray diffraction (XRD) analysis reveled that the SA or KH570 could not change the laminated structure of MoS2. The wearability testing showed that the composites filled by modified MoS2 owned the better wearable performances than the filled not one. From minimum to maximum, the wear mass rates of SA/MoS2/PP/PPS, KH570/MoS2/PP/PPS, PP/PPS were 0.7216, 5.4187 and 7.3198 percent in turns. Scanning electronic microscope (SEM) analysis showed the surface modification could uniformize the modified MoS2 to disperse in the polymeric based composites, and also reflect the abrasion mechanism which the particles and the adhering wear modes could all make the mass loss of the testing samples and they coexisted and could transform each other, the former would produce higher loss rates than the later and their leader status would gradually change from the particles wear to the adhering wear during the course of wearing-resisting tests.

Effects of electron beam irradiation on structure and properties of ultra-high molecular weight polyethylene fiber

2017 ◽  
Vol 47 (6) ◽  
pp. 1357-1377 ◽  
Author(s):  
Dongliang Dai ◽  
Meiwu Shi
Keyword(s):  
Molecular Weight ◽  
Electron Beam ◽  
High Molecular Weight ◽  
Electron Beam Irradiation ◽  
Breaking Strength ◽  
Beam Irradiation ◽  
Elongation At Break ◽  
Gel Content ◽  
Ultra High Molecular Weight ◽  
Polyethylene Fibers

This study introduced trimethylolpropane trimethacrylate into ultra-high molecular weight polyethylene fibers through supercritical CO2 pretreatment before the fibers were irradiated under an electron beam. Significant differences, emerging in the ultra-high molecular weight polyethylene fibers’ gel content, mechanical properties, and creep property according to their different irradiation doses, were studied through one-way analysis of variance. Regression equations were established between the irradiation dose and the gel content, breaking strength, elongation at break, and creep rate by regression analysis. A reasonable irradiation dosage range was determined after a verification experiment and the impact trends were analyzed; additionally, the sensitized irradiation crosslinking mechanism of ultra-high molecular weight polyethylene fibers was preliminarily examined. Then the surface morphology, chemical structures, thermal properties, and crystal properties of treated ultra-high molecular weight polyethylene fibers were measured. The results showed that as the irradiation dose increased, the gel content first rose and then declined; the breaking strength decreased continuously; the elongation at break increased at first and then decreased; and the creep rate originally fell and then rose before finally declining slowly. Electron beam irradiation had a significant etching effect on the fibers’ surface, and both the melting point and crystallinity decreased slightly.

scholarly journals Ultra-high molecular weight elastomeric polyethylene using an electronically and sterically enhanced nickel catalyst

2017 ◽  
Vol 8 (41) ◽  
pp. 6416-6430 ◽  
Author(s):  
Qaiser Mahmood ◽  
Yanning Zeng ◽  
Erlin Yue ◽  
Gregory A. Solan ◽  
Tongling Liang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
High Molecular Weight ◽  
Nickel Catalyst ◽  
High Tensile Strength ◽  
Elongation At Break ◽  
Highly Active ◽  
High Elongation ◽  
Ultra High Molecular Weight ◽  
Shape Fixity

Highly active para-t-Bu-containing 1,2-bis(imino)acenaphthene-Ni(ii) catalysts are disclosed which afford hyper-branched PEs with Mw's up to 3.1 × 106 g mol−1; high tensile strength, excellent shape fixity as well as high elongation at break are a feature.

Determination of Molecular Weight and Structure Characterization of Canna Amylose Purified Using the Method of n-Butanol Recrystallization

2012 ◽  
Vol 554-556 ◽  
pp. 1216-1222
Author(s):  
Hai Xin Shi ◽  
Yan Zhen Yin ◽  
Xiao Xi Hu ◽  
Shu Fei Jiao
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Granule Surface ◽  
Chemical Groups ◽  
Ubbelohde Viscometer

The canna amylose (CAM) was separated from canna starch grown in China and purified both using the method of n-butanol recrystallization. The purity, morphology, spectral properties and molecular weight of CAM were characterized by ultraviolet and visible spectrophotometer (UV/Vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FT-IR) and Ubbelohde viscometer. Maximum absorption wavelength of the purified CAM (635－638 nm) and it’s blue values (BV) (1.167 ± 0.209) prove that the purification of the CAM by n-butanol recrystallization was successfully carried out. The SEM results show that CAM granule surface become rougher and the CAM granule size become smaller than that of canna starch. The XRD results suggest that most of CAM granule is amorphous. And the FT-IR results show that the basic chemical groups of canna starch are also presented in CAM. However, the amorphous area of CAM is increased. The intrinsic viscosity and viscosity-average molecular weight of CAM is 78.5 mL/g and 1.65×105, respectively.

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