scholarly journals Enhancement of Crystallization Behaviors in Quaternary Composites Containing Biodegradable Polymer by Supramolecular Inclusion Complex

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1137
Author(s):  
Li-Ting Lee ◽  
Sheng-Ping He ◽  
Chih-Feng Huang
Keyword(s):  
Inclusion Complex ◽  
Biodegradable Polymer ◽  
Crystallization Rate ◽  
Water Soluble ◽  
Avrami Equation ◽  
Ternary Blend ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
Water Soluble Polymer ◽  
Poly Ethylene

Novel multi-component composites composed of the biodegradable polymer poly(ethylene adipate) (PEA), the water-soluble polymer poly(ethylene oxide) (PEO), poly(vinyl acetate) (PVAc), and a supramolecular-like inclusion complex (IC) made by α-cyclodextrin (α-CD) and poly(ε-caprolactone) (PCL) (coded as PCL–CD–IC) are discussed in this work. The PCL–CD–IC was used to increase the crystallization rate of the miscible PEA/PEO/PVAc ternary blend that crystalized slower than neat PEA. Higher resolution SEM and TEM images displayed that PCL–CD–IC did not assemble notably in the quaternary composites. For the results of isothermal crystallization, the analysis of the Avrami equation demonstrated that the rate constant k increased with the addition of PCL–CD–IC in the composites, suggesting that PCL–CD–IC provided more nucleation sites to promote the crystallization rate. The nucleation density increased with the addition of PCL–CD–IC, and the amount of spherulite also increased. Wide angle X-ray results showed that the composites displayed similar diffraction patterns to neat PEA, meaning PEO, PVAc, and PCL–CD–IC would not change the crystal structures of PEA in the composites. The PCL–CD–IC, the supramolecular nucleation agent, demonstrated its superior ability to enhance the multi-component composites of biodegradable polymer in this study.

scholarly journals Investigations on Novel Ternary Green Polymer Composite

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Ting-Chia Hsu ◽  
Li-Ting Lee ◽  
Xin-Yun Wu
Keyword(s):  
Electron Microscopy ◽  
Hexagonal Boron Nitride ◽  
Crystallization Rate ◽  
Avrami Equation ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
K Value ◽  
Nucleation Effect ◽  
Poly Ethylene ◽  
Green Polymer

In this study, the novel ternary green polymer composites of poly(l-lactic acid) (PLLA)/poly(ethylene adipate)/hexagonal boron nitride (PLLA/PEA/h-BN) were synthesized and prepared. The crystallization rate of the biodegradable polymer PLLA in the composite was significantly increased with the addition of PEA and functional h-BN. In ternary PLLA/PEA/h-BN composites, PEA can be used as a plasticizer, while h-BN is a functional nucleation agent for PLLA. The analysis of the isothermal crystallization kinetics by the Avrami equation shows that the rate constant k of the ternary PLLA/PEA/h-BN composite represents the highest value, indicating the highest crystallization in the ternary composite. Adding h-BN in the composite can further increase the k value and increase the crystallization rate. Polarized optical microscopy (POM) images reveal that h-BN is an effective nucleation agent that increases the nucleation density of composites. Analysis of wide-angle X-ray diffraction (WAXD) further confirmed that the crystalline structures of PLLA were unchanged by the addition of PEA and h-BN. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that the h-BN particles are uniformly distributed in the composite. The distribution of h-BN having a particle size of a few hundred nm causes an effective nucleation effect and promotes the crystallization of the ternary composites.

scholarly journals DESIGN, DEVELOPMENT, AND CHARACTERIZATION OF OROMUCOSAL WAFER OF TRAMADOL HYDROCHLORIDE

2018 ◽  
Vol 11 (8) ◽  
pp. 116
Author(s):  
Rita N Wadetwar ◽  
Tejaswini Charde
Keyword(s):  
Drug Release ◽  
Biodegradable Polymer ◽  
Research Work ◽  
Water Soluble ◽  
Content Uniformity ◽  
Onset Of Action ◽  
Water Soluble Polymer ◽  
Surface Ph ◽  
Folding Endurance

Objective: The objective of the present work was the preparation of fast-dissolving film of tramadol HCl (TMH) using water-soluble polymer, to achieve faster onset of action, to improve patient compliance, ease of dosing, and bypass the first-pass metabolism. Methods: TMH oromucosal wafers were prepared using pullulan as natural, biodegradable polymer, and propylene glycol as plasticizer by solvent casting method. Formulation batches were prepared using 32 full-factorial designs. The prepared TMH oromucosal wafers were characterized for morphology, uniformity of weight, drug content, folding endurance, in vitro disintegration time (DT), % moisture content, surface pH, in vitro % drug release, ex vivo permeation studies, compatibility studies (differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffraction), and stability studies.Results: Optimized batch of mouth-dissolving film of TMH containing pullulan as polymer showed 98.67±0.11% drug release at 6 min. It showed better folding endurance 88 No. of folds, in vitro DT 5.11 s, surface pH 6.84±0.12 pH, thickness 0.17±0.11 mm, and percentage content uniformity 98.45±0.48%. Stability studies carried out for the best formulation FDF5 revealed that the formulation was stable.Conclusion: The results obtained in this research work clearly indicated a promising potential of fast-dissolving oral films using natural biodegradable polymer, pullulan which gave rapid drug delivery and rapid onset of action of centrally acting drug, TMH for patients suffering from pain.

Effect of Zeolite as a Green Catalyst and Nucleation Agent on the Physical Properties of Poly(Ethylene 2,5-Furan-Dicarboxylate)

2018 ◽  
Vol 773 ◽  
pp. 88-93
Author(s):  
Je Young Park ◽  
Dong Yeop X. Oh ◽  
Tae Ho Kim ◽  
Sung Yeon Hwang
Keyword(s):  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Crystallization Rate ◽  
Melt Crystallization ◽  
Nucleation Agent ◽  
Weight Average Molecular Weight ◽  
Green Catalyst ◽  
Highest Weight ◽  
Poly Ethylene

In this study, poly(ethylene 2,5-furan dicarboxylate) (PEF) was synthesized from biomass-based dimethyl furan-2,5-dicarboxylate using different-sized zeolites, with substituted ions such as Li and K, as efficient green catalysts for in situ polymerization. The Z5Ali catalyst yielded the PEF biopolyester with the highest weight-average molecular weight among all the samples: 53,800 g/mol. From their TGA curves, it was confirmed that the PEF sample with ZA5Li as the catalyst showed an increased thermal stability compared to homo-PEF. Generally, homo-PEF exhibited a very low melt-crystallization rate with low enthalpy. However, all the PEF samples using zeolite as the catalyst formed endotherms I and II. This result was attributed to the fact that zeolite affects the melt and recrystallization of imperfect crystals due to physical hindrance.

scholarly journals Effect of Cyanuric Acid as an Efficient Nucleating Agent on the Crystallization of Novel Biodegradable Branched Poly(Ethylene Succinate)

Macromol ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 112-120
Author(s):  
Kangjing Zhang ◽  
Zhaobin Qiu
Keyword(s):  
Cyanuric Acid ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Crystallization Mechanism ◽  
Nucleation Density ◽  
Half Time ◽  
Melt Crystallization ◽  
Casting Method ◽  
Crystallization Peak ◽  
Poly Ethylene

Novel biodegradable branched poly(ethylene succinate) (b-PES) composites, i.e., nucleated b-PES samples, were prepared by incorporating low loadings of cyanuric acid (CA) through a solution and casting method to enhance the crystallization rate. As an efficient nucleating agent, CA could remarkably increase the nonisothermal melt crystallization peak temperature, shorten the crystallization half-time, accelerate the overall isothermal melt crystallization, and enhance the nucleation density of b-PES spherulites in the composites. Despite the addition of CA, the crystallization mechanism and crystal structure of b-PES remained unchanged. A possible epitaxial crystallization mechanism may account for the nucleation of b-PES crystals induced by CA.

Mechanical enhancement and crystallization kinetics of polyoxymethylene-based composite film with carbon nanotube

2015 ◽  
Vol 30 (5) ◽  
pp. 599-607 ◽  
Author(s):  
Peng Chunzheng ◽  
Cai Chilan ◽  
Tian Haobin ◽  
Zhang Jianguo
Keyword(s):  
Carbon Nanotube ◽  
Composite Film ◽  
Interfacial Adhesion ◽  
Crystallization Rate ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
Thermal Stabilities ◽  
The Matrix ◽  
Reinforcing Material ◽  
Kinetics Of

Carbon nanotube (CNT) was employed as a reinforcing material to prepare polyoxymethylene (POM)-based composite film through a simple melting extrusion. An effective approach was developed to clean and modify the surface of as-received CNT with nitric acid and then with a silane coupling agent. The mechanical evaluation demonstrated that a significant reinforcement was achieved for POM/CNT composites due to the improved interfacial adhesion between CNT and the matrix. The thermal stabilities of the composites were also improved in the presence of CNT. The studies on crystallization behaviors showed that CNT acted as a nucleation agent for the crystallization of POM domain in composites, and therefore, the crystallization rate and nucleation density increased remarkably due to the heterogeneous nucleating effect of CNT.

Preparation of poly(L-lactide)/poly(ethylene glycol)/organo-modified montmorillonite nanocomposites via melt intercalation under continuous elongation flow

2018 ◽  
Vol 38 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Ting Wu ◽  
Ding Yuan ◽  
Jin-Ping Qu
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Nucleation Density ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Modified Montmorillonite ◽  
Elongation Flow ◽  
Poly Ethylene

AbstractAn innovative eccentric rotor extruder (ERE), which can generate continuous elongation flow, was used to prepare the poly(L-lactide) (PLLA)/poly(ethylene glycol) (PEG)/organo-modified montmorillonite (OMMT) nanocomposites. The morphology was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and showed that the OMMT nanoparticles were uniformly dispersed in the matrix and mainly existed in intercalation mode. The influence of OMMT on the rheological behavior of plasticized PLLA was investigated by dynamic rheological measurements, showing greater improvement of rheological properties compared to that of PLLA/PEG blend. The crystallization behavior and crystalline structures were studied by differential scanning calorimetry (DSC) and XRD, respectively, and showed that the presence of OMMT further speeds up the crystallization rate of plasticized PLLA. However, the crystallization rate and crystallinity had a slight downward trend at high OMMT content because of the inhibition effect of the OMMT percolation network structure. Polarizing optical microscopy (POM) was further carried out and proved that the OMMT nanoparticles as a heterogeneous nucleating agent can increase the spherulite growth rate and nucleation density. The thermal stability was investigated by thermogravimetric analysis and indicated that the addition of OMMT at low concentration can improve the thermal stability of plasticized PLLA more effectively.

Non-Isothermal Crystallization Behavior of Poly(Ethylene Terephthalate)/Carbon Black Composite

2011 ◽  
Vol 239-242 ◽  
pp. 3198-3206 ◽  
Author(s):  
Zhao Hui Jiang ◽  
Jian Jin ◽  
Chang Fa Xiao ◽  
Xin Li
Keyword(s):  
Crystal Growth ◽  
Carbon Black ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Crystal Nucleation ◽  
Avrami Equation ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Poly(Ethylene Terephthalate)(PET)/carbon black(CB) composite was prepared by melt blending using a separate feeding technique. The non-isothermal crystallization process of virgin PET and PET/CB composite were investigated by differential scanning calorimetry (DSC) and the different methods such as Jeziorny modified Avrami equation, Ozawa equation and the method developed by Mo were employed to analyze the non-isothermal kinetics of virgin PET and PET/CB composite. The results show that the CB particles dispersed in PET matrix act as heterogeneous nucleating agents, while CB particles hinder the movement of molecular chains of PET, meanwhile, the crystallization activation energy(⊿E) of PET/CB composite is much greater than that of virgin PET according to Kissinger formula, which is opposite to the low CB content condition. This indicates that CB particles reduce the rate of crystal growth. Whereas, the results obtained from the mentioned three methods simultaneously demonstrate the addition of CB greatly increases crystallization temperature and crystallinity and accelerates crystallization rate. Taking the two seemingly contradictory results, crystal growth has little effect on the crystallization rate and crystal nucleation dominate the crystallization process of PET/CB composite with very high CB content. According to Jeziorny method, the constant of crystallization rate (Zc) increases with the increment of cooling rate and Avrami index (n) doesn’t change significantly, but the Zc and n of PET/CB composite are greater than that of PET. Based on Ozawa method, lg[-ln(1-Xt)] and lgR don’t show a good linear relationship. The parameter F(T) increases significantly with the increasing of relative crystallinity and n is almost unchanged. Besides, the F(T) of PET/CB composite is less than that of PET, while a is greater than that of PET. Comparing with Ozawa and Avrami equation, Mo method can better describe the non-isothermal crystallization of PET and PET/CB composite.

Effect of Water Soluble Polymers on Radiation Vulcanized Natural Rubber Latex Films

1999 ◽  
Vol 72 (2) ◽  
pp. 308-317 ◽  
Author(s):  
Siby Varghese ◽  
Yosuke Katsumura ◽  
Keizo Makuuchi ◽  
Fumio Yoshi
Keyword(s):  
Natural Rubber Latex ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Radiation Processing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Drastic Increase ◽  
Poly Ethylene

Abstract Technological properties of radiation vulcanized latex after mixing with water soluble polymers (WSP) such as poly(vinyl alcohol), poly(ethylene oxide) etc. have been studied in detail. The properties of water soluble polymer incorporated vulcanizates depend mainly on the type of the polymer blended into the latex. Most of the polymers showed a drastic increase in tear strength with polymer content and a reduction in tackiness of the vulcanized films. Radiation processing increases the water soluble protein content in the serum phase whereas that in the rubber phase decreases. Addition of water soluble polymer causes the fast leaching of soluble proteins from the dried films, which reduces the prolonged leaching commonly adopted for rubber vulcanizates. Aging properties of radiation vulcanized films incorporated with water soluble polymers are excellent. The thermal degradation behavior of radiation vulcanized films and that of water soluble polymer incorporated films is almost the same. Transparency of the rubber films can be increased by the addition of suitable water soluble polymers.

scholarly journals Crystallization Behaviors of Composites Comprising Biodegradable Polyester and Functional Nucleation Agent

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1260
Author(s):  
Li-Ting Lee ◽  
Hsiang-Yun Tseng ◽  
Tzi-Yi Wu
Keyword(s):  
Isothermal Crystallization ◽  
Hexagonal Boron Nitride ◽  
Crystallization Rate ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Nucleation Agent ◽  
Sem Images ◽  
Crystallization Behaviors ◽  
Nucleation Effect ◽  
Xrd Diffraction

In this study, a thorough study of the crystallization behaviors of the biodegradable polymer composites of poly(ethylene succinate) (PESu) and hexagonal boron nitride (h-BN) was carried out. We found that h-BN had a significant nucleation effect on crystallization behaviors. DSC isothermal crystallization results demonstrated that the crystallization time of the PESu/h-BN composites became shorter after adding h-BN. The rate constant k values calculated from the Avrami equation were larger for the composites, demonstrating that PESu’s crystallization rate was increased by adding h-BN. TEM and SEM images showed the well-dispersed h-BN in the PESu matrix. Optical microscopy revealed that the PESu/h-BN composites formed more and smaller spherulites than neat PESu did, which confirmed that h-BN caused the nucleation effect. H-BN also accelerated non-isothermal crystallization kinetics. We discussed the behaviors of the Mo model, which demonstrated that h-BN promoted the kinetics of non-isothermal crystallization. The XRD diffraction patterns showed that h-BN in the composites would not obviously change the crystalline structure of PESu.

scholarly journals Cd(II) extraction in PEG(1550)-(NH4)2SO4 aqueous two-phase systems using halide extractants

2008 ◽  
Vol 73 (3) ◽  
pp. 341-350 ◽  
Author(s):  
Laura Bulgariu ◽  
Dumitru Bulgariu
Keyword(s):  
Distribution Coefficients ◽  
Water Soluble ◽  
Phase System ◽  
Halide Ions ◽  
Two Phase ◽  
Water Soluble Polymer ◽  
Rich Phase ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
Poly Ethylene

The extraction of Cd(II) was studied in an aqueous PEG-(NH4)2SO4 two-phase system, formed from a water-soluble polymer (poly(ethylene glycol), PEG) and an inorganic salt ((NH4)2SO4), in the presence of halide ions. In the absence of a suitable extracting agent, Cd(II) remains predominantly in the salt-rich phase of the extraction system. By addition of halide ions as extractants, Cd(II) is extracted into the PEG-rich phase due to the formation of cadmium halide species. The efficiency of the extractants increased in the order: Cl- < Br- < I-. From the distribution coefficients determined as a function of the concentration of the halide ions, the compositions of the extracted species were assumed and the "conditional" extractions constants calculated. The experimental results indicate that the extractability of Cd(II) in such extraction systems depends on the type of Cd(II) halide species (which is mainly determined by the acidity of salt stock solution) and of their stability.

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