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.

scholarly journals Significantly Enhanced Crystallization of Poly(ethylene succinate-co-1,2-propylene succinate) by Cellulose Nanocrystals as an Efficient Nucleating Agent

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 224
Author(s):  
Siyu Pan ◽  
Zhiguo Jiang ◽  
Zhaobin Qiu
Keyword(s):  
Crystal Structure ◽  
Cellulose Nanocrystals ◽  
Crystallization Behavior ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Melt Crystallization ◽  
Crystalline Morphology ◽  
Poly Ethylene

Poly(ethylene succinate-co-1,2-propylene succinate) (PEPS) is a novel aliphatic biodegradable polyester with good mechanical properties. Due to the presence of methyl as a side group, the crystallization rate of PEPS is remarkably slower than that of the poly(ethylene succinate) homopolymer. To promote the potential application of PEPS, the effect of cellulose nanocrystals (CNC) on the crystallization behavior, crystalline morphology, and crystal structure of PEPS was investigated in this research with the aim of increasing the crystallization rate. CNC enhanced both the melt crystallization behavior of PEPS during the cooling process and the overall crystallization rate during the isothermal crystallization process. The crystallization rate of PEPS became faster with an increase in CNC content. The crystalline morphology study directly confirmed the heterogeneous nucleating agent role of CNC. The crystal structure of PEPS remained unchanged in the composites. On the basis of the interfacial energy, the nucleation mechanism of PEPS in the composites was further discussed by taking into consideration the induction of CNC.

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.

scholarly journals Melt Crystallization Behavior and Crystalline Morphology of Polylactide/Poly(ε-caprolactone) Blends Compatibilized by Lactide-Caprolactone Copolymer

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1181 ◽  
Author(s):  
Chunmei Zhang ◽  
Qiaofeng Lan ◽  
Tianliang Zhai ◽  
Shengqiang Nie ◽  
Jun Luo ◽  
...  
Keyword(s):  
Crystallization Behavior ◽  
Crystallization Time ◽  
Half Time ◽  
Melt Crystallization ◽  
Crystalline Morphology ◽  
Casting Method ◽  
Three Samples ◽  
Significant Difference ◽  
Compatibilization Effect ◽  
Kinetics Of

Lactide-Caprolactone copolymer (LACL) was added to a Polylactide/Poly(ε-caprolactone) (PLA/PCL) blend as a compatibilizer through solution mixing and the casting method. The melt crystallization behavior and crystalline morphology of PLA, PLA/PCL, and PLA/PCL/LACL were investigated using differential scanning calorimeter (DSC) and polarized optical microscopy (POM), respectively. The temperature of the shortest crystallization time for the samples was observed at 105 °C. The overall isothermal melt crystallization kinetics of the three samples were further studied using the Avrami theory. Neat PLA showed a higher half-time of crystallization than that of the PLA/PCL and PLA/PCL/LACL blends, whereas the half-time of crystallization of PLA/PCL and PLA/PCL/LACL showed no significant difference. The addition of PCL decreased the spherulite size of crystallized PLA, and the nuclei density in the PLA/PCL/LACL blend was much higher than that of the PLA and PLA/PCL samples, indicating that LACL had a compatibilization effect on the immiscible PLA/PCL blend, thereby promoting the nucleation of PLA. The spherulites in the PLA/PCL and PLA/PCL/LACL blend exhibited a smeared and rough morphology, which can be attributed to the fact that PCL molecules migrated to the PLA spherulitic surface during the crystallization of PLA.

Effect of Cellulose Nanocrystal on Crystallization Behavior of Poly(3–hydroxybutyrate–co–3–hydroxyvalerate)

2012 ◽  
Vol 430-432 ◽  
pp. 20-23 ◽  
Author(s):  
Hou Yong Yu ◽  
Zong Yi Qin
Keyword(s):  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Kinetics Study ◽  
Solvent Casting ◽  
Melt Crystallization ◽  
Casting Method ◽  
Isothermal Crystallization Kinetics ◽  
Biodegradable Nanocomposites

The biodegradable nanocomposites of poly (3–hydroxybutyrate–co–3–hydroxyvalerate) (PHBV) with different cellulose nanocrystals (CNCs) contents were prepared by a solvent casting method. The effects of CNCs on the crystallization behavior of PHBV were studied by DSC. The DSC results showed that compared to PHBV, the melt crystallization temperature increased to 92.3 °C for the nanocomposites with 10 wt. % CNCs, which indicated that the crystallization of PHBV became easier with the addition of CNCs. Moreover, the non–isothermal crystallization kinetics study illustrated that overall crystallization rate of PHBV in the nanocomposites was faster than that of neat PHBV, which should be attributed to the strong heterogeneous nucleation of CNCs.

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 UIO-66 as Nucleating Agent on the Crystallization Behavior and Properties of Poly(Ethylene Terephthalate)

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2266
Author(s):  
Yue Yin ◽  
Yuan Wang ◽  
Linghui Meng
Keyword(s):  
Tensile Strength ◽  
Specific Surface ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Ethylene Terephthalate ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
High Specific Surface Area ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

In this study, not only was the similar terephthalate structure between UIO-66 and PET utilized to improve compatibility, but the Zr4+ exposed by defects of UIO-66 was also utilized to improve the interaction between PET and UIO-66. Furthermore, PET nanocomposites with different contents of UIO-66 were also fabricated. Due to the high specific surface area and coordination of Zr4+, UIO-66 has high nucleation efficiency in the PET matrix. Compared with pure PET, the crystallization rate of PET/UIO-66 nanocomposite is significantly increased, and the crystallization temperature of PET-UIO66-1 is significantly increased from 194.3 °C to 211.6 °C. In addition, the tensile strength of nanocomposites has also been improved due to coordination.

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.

Crystallization and properties of nucleated poly(l-lactic acid): Effect of cyclopentanecarboxylic acid derivative as a new nucleating agent

2021 ◽  
pp. 089270572110019
Author(s):  
Lisha Zhao ◽  
Xuhua Liu ◽  
Yanhua Cai ◽  
Wei Chen
Keyword(s):  
Lactic Acid ◽  
Cooling Rate ◽  
Melting Temperature ◽  
Tensile Modulus ◽  
Nucleating Agent ◽  
Orbital Energy ◽  
Melt Crystallization ◽  
Promoting Effect ◽  
Crystallization Peak ◽  
Lower Temperature

In this study, the potential effects of N, N’-dodecanedioic bis(cyclopentanecarboxylic acid) dihydrazide (BCADD) as a new additive in poly(L-lactic acid) (PLLA) was estimated. The comparative study on the melt-crystallization showed that the BCADD as heterogeneous nuclei facilitated crystallization of PLLA in cooling, which indicated by the obvious crystallization exotherms and sharp melt-crystallization peak. Unfortunately, with increasing of BCADD from 0.5 wt% to 3 wt%, it is unexpected that the melt-crystallization peak of the BCADD-nucleated PLLA shifted toward the lower temperature and became flatter, evidencing the importance of BCADD loading for PLLA’s crystallization. Additionally, the cooling rate and the final melting temperature were also proved to be important influence factors during PLLA’s melt-crystallization process, but in contrast with the effect of the final melting temperature on the melt-crystallization, a higher cooling rate could more seriously weaken crystallization ability of the BCADD-nucleated PLLA. The chemical nucleation mechanism was proposed to explain the promoting effect of BCADD on the crystallization of PLLA via the analysis of frontier orbital energy. The melting behaviors after crystallization further confirmed the crystallization accelerating role of BCADD, and the melting behaviors were affected by the heating rate, crystallization temperature and BCADD loading. Although the onset thermal decomposition of the BCADD-nucleated PLLA occurred at lower temperature comparing with the pure PLLA, the intermolecular interaction of PLLA with BCADD attempted to prevent the decrease of thermal stability. Overall, the addition of BCADD resulted in the complicated effect on the tensile modulus and tensile strength of PLLA, but the elongation at break continuously decreased when increasing BCADD loading.

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