Thermal Performances and Fluidity of Biodegradable Poly(L-lactic acid) Filled with N, N'-Oxalyl Bis(piperonylic acid) Dihydrazide as a Nucleating Agent

Materials Science ◽

10.5755/j02.ms.25139 ◽

2021 ◽

Author(s):

Lisha ZHAO ◽

Yanhua CAI

Keyword(s):

Lactic Acid ◽

Temperature Region ◽

Nucleating Agent ◽

Melting Behavior ◽

Decomposition Temperature ◽

Melt Crystallization ◽

Biodegradable Poly ◽

Negative Effect ◽

Infrared Spectrometer ◽

Onset Decomposition Temperature

N, N'-oxalyl bis(piperonylic acid) dihydrazide (PAOD) was obtained through the amination of piperonylic acid chloride and its structure was characterized by Fourier transform infrared spectrometer and nuclear magnetic resonance. Melting blend technology was used to prepare the modified poly(L-lactic acid) (PLLA) containing the various loading PAOD as a new organic nucleating agent. The thermal performances including crystallization, melting behavior and thermal decomposition process, as well as the fluidity of PAOD-nucleated PLLA were investigated via a series of tests. The DSC results showed that, in comparison to DSC curve of the virgin PLLA, the DSC curves of all PLLA/PAOD appeared the sharp melt-crystallization peak, and a higher PAOD concentration caused the melt-crystallization to occur in the higher temperature region and reduced the negative effect of the high cooling rate on the melt-crystallization process. However, with increasing of PAOD concentration, the cold-crystallization enthalpy decreased from 24.4 J/g to 16.7 J/g. The melting peak after melt-crystallization depended on the heating rate and the PAOD concentration; and the double melting peaks appeared after isothermal crystallization in low temperature region was thought to be due to the melting-recrystallization. The addition of PAOD decreased the onset decomposition temperature of PLLA, but the onset decomposition temperature was determined by the PAOD concentration and the intermolecular interaction of PLLA and PAOD. Additionally, the PAOD could considerably improve the fluidity of PLLA.

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A 1H-Benzotriazole Derivative Nucleated Poly(L-lactic acid): Thermal Behavior and Physical Properties

Journal of the chemical society of pakistan ◽

10.52568/000648 ◽

2020 ◽

Vol 42 (3) ◽

pp. 383-383

Author(s):

Li Sha Zhao and Yan Hua Cai Li Sha Zhao and Yan Hua Cai

Keyword(s):

Thermal Stability ◽

Lactic Acid ◽

Melting Process ◽

Nucleating Agent ◽

Melting Behavior ◽

Cold Crystallization ◽

Melt Crystallization ◽

Nucleation Effect ◽

Lower Temperature ◽

Thermal Stability Of

In this study, a 1H-benzotriazole derivative, N, Nand#39;-bis(1H-benzotriazole) succinic acid acethydrazide (SABHA), was synthesized to nucleate Poly(L-lactic acid) (PLLA). A series of comparative studies on the melt-crystallization, the cold-crystallization, the melting behavior, the thermal stability, as well as the fluidity between the pure PLLA and PLLA/SABHA were performed. The melt-crystallization behavior revealed that the SABHA as a heterogeneous nucleating agent could significantly facilitate the crystallization of PLLA, and a larger amount of SABHA concentration exhibited the better nucleation effect. However, for the cold-crystallization process, the crystallization peak shifted toward the lower temperature with increasing of SABHA concentration. The melting behavior after crystallization at different crystallization temperatures showed that the melting process of PLLA/SABHA samples depended on the crystallization temperature, and the appearance of the double melting peaks was attributed to the melt-recrystallization. The thermal decomposition profile of PLLA was not affected by SABHA, but the addition of SABHA reduced the thermal stability of PLLA. Fortunately, the presence of SABHA improved the fluidity of PLLA, and the effect of SABHA concentration on the fluidity was positive.

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Thermal behavior of modified poly(L-lactic acid): effect of aromatic multiamide derivative based on 1H-benzotriazole

e-Polymers ◽

10.1515/epoly-2016-0052 ◽

2016 ◽

Vol 16 (4) ◽

pp. 303-311 ◽

Cited By ~ 6

Author(s):

Yan-Hua Cai ◽

Li-Sha Zhao

Keyword(s):

Thermal Stability ◽

Thermal Decomposition ◽

Lactic Acid ◽

Isothermal Crystallization ◽

Crystallization Behavior ◽

Nucleating Agent ◽

Melting Behavior ◽

Decomposition Temperature ◽

Scanning Calorimetry ◽

Onset Crystallization Temperature

AbstractThe goal of this work was to synthesis a novel aromatic multiamide derivative based on 1H-benzotriazole (PB) as an organic nucleating agent for poly(L-lactic acid) (PLLA), and investigate the effect of PB on the non-isothermal crystallization, melting behavior and thermal decomposition of PLLA. Here, PB was firstly synthesized through 1H-benzotriazole aceto-hydrazide and terephthaloyl chloride, then PB-nucleated PLLA was fabricated via melt-blending technology at various PB concentration from 0.5 wt% to 3 wt%. Finally, the thermal performances were evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The high thermal decomposition temperature of PB indicated that PB possessed possibility as a nucleating agent for PLLA, and the non-isothermal crystallization behavior confirmed the crystallization accelerating effectiveness of PB for PLLA. Upon optimum concentration of 2 wt%, the onset crystallization temperature, the crystallization peak temperature and the non-isothermal crystallization enthalpy increased from 101.4°C, 94.5°C and 0.1 J·g-1 to 121.3°C, 115.8°C and 35.1 J·g-1, respectively. In addition, the non-isothermal crystallization behavior was also affected by the cooling rate and the final melting temperature. The melting behavior further evidenced the advanced nucleating ability of PB, and the competitive relationship between PB and the heating rate, the nuclear rate and crystal growth rate. Thermal stability measurement showed that PB with a concentration of 1 wt%–2 wt% could slightly improve the thermal stability of PLLA.

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Crystallization and Melting Behavior of Biodegradable Poly(L-lactic acid)/Talc Composites

E-Journal of Chemistry ◽

10.1155/2012/570752 ◽

2012 ◽

Vol 9 (3) ◽

pp. 1569-1574 ◽

Cited By ~ 14

Author(s):

Yan-Hua Cai

Keyword(s):

Lactic Acid ◽

Heating Rate ◽

Isothermal Crystallization ◽

Crystallization Rate ◽

Melting Behavior ◽

Melting Peak ◽

Melt Crystallization ◽

Biodegradable Poly ◽

Crystallization And Melting Behavior ◽

Double Melting Peak

Crystallization and melting behavior of Poly(L-lactic acid)(PLLA)/Talc composites with different talc content were investigated in detail. The addition of talc can increase the overall crystallization rate of PLLA, 5%talc makes the melt-crystallization peak temperature of PLLA increase from 96.28 °C to 105.22 °C, and the crystallization enthalpy increases from 1.379 J•g-1to 28.99 J•g-1. The melting behavior of PLLA/5%talc composites at a different heating rate during non-isothermal crystallization at different cooling rate shows that heating rate can affect the melting behavior of PLLA, with increasing of heating rate, the double melting peak degenerates to single melting peak. Melting behavior after isothermal crystallization and after cold isothermal crystallization and hot isothermal crystallization indicates that the double-melting peak of PLLA/5%talc composites results from melting-recrystallization.

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Insight into the Role of a Isophthalic Dihydrazide Derivative Containing Piperonylic Acid in Poly(L-lactide) Nucleation: Thermal Performances and Mechanical Properties

Materiale Plastice ◽

10.37358/mp.20.3.5377 ◽

2020 ◽

Vol 57 (3) ◽

pp. 28-40

Author(s):

Hao Huang ◽

Yan-Hua Zhang ◽

Li-Sha Zhao ◽

Guang-Ming Luo ◽

Yan-Hua Cai

Keyword(s):

Mechanical Properties ◽

Nucleating Agent ◽

Melting Behavior ◽

Decomposition Temperature ◽

Melting Peak ◽

Melt Crystallization ◽

Scanning Calorimetry ◽

Melt Temperature ◽

Onset Crystallization Temperature ◽

Tensile Tester

This work was aimed at synthesizing the N, N -isophthalic bis(piperonylic acid) dihydrazide (PAID) to be as a new crystallization accelerator for poly(L-lactide) (PLLA), and a detailed investigations of the non-isothermal crystallization, melting behavior, thermal decomposition behavior and mechanical properties of PLLA nucleated by PAID were performed applying differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and electronic tensile tester. The melt-crystallization proved that the PAID could act as a heterogeneous nucleating agent to significantly promote the crystallization in cooling, even the crystallization was still able to be accelerated upon the fast cooling at 50 oC/min. The final melt temperature was another crucial factor for PLLA�s melt crystallization, and when the final melt temperature was 170 oC, the onset crystallization temperature and melt-crystallization enthalpy was almost up to 150 oC and 56.8 J/g upon cooling of 1 oC/min, respectively. Furthermore, the chemical nucleation was proposed to be the nucleation mechanism of PAID for PLLA via the preliminary theoretical calculation. For the cold-crystallization, the addition of PAID exhibited an inhibition for the crystallization of PLLA, but the total crystallization process depended on the heating rate and PAID concentration. The single melting peak after cooling of 1 oC/min indicated that the crystallization had been thoroughly completed in cooling. Additionally, the single melting peak with different locations after full crystallization resulted from the different crystallization temperatures. A comparison in the onset decomposition temperature implied that the presence of PAID only slightly decreased the thermal stability of PLLA. The mechanical testing showed that, in contrast with the elongation at break, the existence of PAID enhanced the tensile strength of PLLA.

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Poly (L-lactic acid) Modified by N, N -bis(Stearic acid)-1,4-Dicarboxybenzene Dihydrazide: Studies of Crystallization, Melting Behavior and Thermal Decomposition

Materiale Plastice ◽

10.37358/mp.21.4.5533 ◽

2022 ◽

Vol 58 (4) ◽

pp. 73-83

Author(s):

Hao Huang ◽

Shuang-Qing Liu ◽

Cheng-Pei Li ◽

Shi-Tianle Luo ◽

Li-Sha Zhao ◽

...

Keyword(s):

Thermal Stability ◽

Thermal Decomposition ◽

Lactic Acid ◽

Stearic Acid ◽

Isothermal Crystallization ◽

Crystallization Process ◽

Nucleating Agent ◽

Melting Behavior ◽

Melt Crystallization ◽

Thermal Stability Of

In this study, a new organic nucleating agent N, N -bis(stearic acid)-1,4-dicarboxybenzene dihydrazide (PASH) to improve crystallization behavior of poly(L-lactic acid) (PLLA) along with the effect of PASH on melting behavior, thermal stability of PASH-nucleated PLLA was holistically reported. The melt-crystallization process illustrated that PASH as an effective heterogeneous nucleating agent could boost PLLA�s crystallization rate, but increasing PASH concentration and cooling rate conversely inhibited melt-crystallization process of PLLA in this study. With respect to melt-crystallization process, a larger amount of PASH leaded to a shift of cold-crystallization peak to lower temperature level. Isothermal crystallization revealed, in comparison to pure PLLA, that the half time of overall crystallization of PLLA/PASH was significantly decreased with PLLA containing 3 wt% PASH having the minimum t1/2= 67.3 s at 105şC. The different melting behaviors of PLLA/PASH under different conditions were attributed to the nucleating effect of PASH within PLLA. In particular, the melting behavior at a heating rate of 10�C/min after isothermal crystallization depended primarily on the crystallization temperature. Whereas, the impact of crystallization time on melting behavior was negligible. Nonetheless, the melting behavior was influenced by the heating rate after non-isothermal crystallization. The thermal stability of PLLA was detrimental with the addition of PASH owing to a typical drop in onset thermal decomposition temperature.

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N, N’-sebacic bis(hydrocinnamic acid) dihydrazide: A crystallization accelerator for poly(L-lactic acid)

e-Polymers ◽

10.1515/epoly-2019-0016 ◽

2019 ◽

Vol 19 (1) ◽

pp. 141-153 ◽

Cited By ~ 1

Author(s):

Li-Sha Zhao ◽

Yan-Hua Cai ◽

Hui-Li Liu

Keyword(s):

Thermal Stability ◽

Lactic Acid ◽

Isothermal Crystallization ◽

Nucleating Agent ◽

Melting Behavior ◽

Cold Crystallization ◽

Light Transmittance ◽

Nucleation Density ◽

Melt Crystallization ◽

Hydrocinnamic Acid

AbstractDeveloping more organic nucleating agent with different molecular structure is very instructive to improve the crystallization of poly(L-lactic acid) (PLLA) and explore the crystallization mechanism. In this study, N, N’-sebacic bis(hydrocinnamic acid) dihydrazide (HAD) was synthesized to serve as a nucleating agent for PLLA. The effects of HAD on the non-isothermal crystallization, melting behavior, thermal stability and optical performance of PLLA were investigated by differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and light transmittance meter. The melt crystallization behavior showed that HAD was able to promote the crystallization of PLLA via heterogenous nucleation in cooling, and it was found that, upon the cooling of 1°C/min, the incorporation of 1 wt% HAD made the crystallization temperature and non-isothermal crystallization enthalpy increase from 94.5°C and 0.1 J/g to 131.6°C and 48.5 J/g comparing with the pure PLLA. Additionally, the melt crystallization significantly depended on the cooling rate and the final melting temperature. For the cold crystallization, when the nucleation density from HAD and PLLA itself was saturated, the influence of the HAD concentration on the cold crystallization process of the PLLA/HAD samples is negligible. The melting behavior after isothermal or non-isothermal crystallization further confirmed the crystallization accelerating effect of HAD for PLLA, and the appearance of the double melting peaks was attributed to the melting-recrystallization. Unfortunately, the addition of HAD decreased the thermal stability and light transmittance of PLLA.

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The Effect of WS2 Nanosheets on the Non-Isothermal Cold- and Melt-Crystallization Kinetics of Poly(l-lactic acid) Nanocomposites

Polymers ◽

10.3390/polym13132214 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2214

Author(s):

Mohammed Naffakh ◽

Pablo Rica ◽

Carmen Moya-Lopez ◽

José Antonio Castro-Osma ◽

Carlos Alonso-Moreno ◽

...

Keyword(s):

Lactic Acid ◽

Transition Metal Dichalcogenides ◽

Crystallization Rate ◽

Melting Behavior ◽

Hybrid Nanocomposites ◽

Melt Crystallization ◽

Heating Rates ◽

Solution Blending ◽

New Perspective ◽

Ws2 Nanosheets

In the present work, hybrid nanocomposite materials were obtained by a solution blending of poly(l-lactic acid) (PLLA) and layered transition-metal dichalcogenides (TMDCs) based on tungsten disulfide nanosheets (2D-WS2) as a filler, varying its content between 0 and 1 wt%. The non-isothermal cold- and melt-crystallization and melting behavior of PLLA/2D-WS2 were investigated. The overall crystallization rate, final crystallinity, and subsequent melting behavior of PLLA were controlled by both the incorporation of 2D-WS2 and variation of the cooling/heating rates. In particular, the analysis of the cold-crystallization behavior of the PLLA matrix showed that the crystallization rate of PLLA was reduced after nanosheet incorporation. Unexpectedly for polymer nanocomposites, a drastic change from retardation to promotion of crystallization was observed with increasing the nanosheet content, while the melt-crystallization mechanism of PLLA remained unchanged. On the other hand, the double-melting peaks, mainly derived from melting–recrystallization–melting processes upon heating, and their dynamic behavior were coherent with the effect of 2D-WS2 involved in the crystallization of PLLA. Therefore, the results of the present study offer a new perspective for the potential of PLLA/hybrid nanocomposites in targeted applications.

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