Article
Polymer Science
Lidong Feng, Xinchao Bian, Gao Li, Xuesi Chen
Summary: By investigating the thermal properties, morphology, and thermal stability of PLLA/PDLA blends, a new stereoamorphous mesophase (sam-PLA) structure was discovered, and the relationship between different phases in the PLLA/PDLA blends was explored.
Article
Thermodynamics
Hechang Shi, Hongda Cheng, Changyu Han, Yanchun Yu, Mengdie Yu, Ye Zhang
Summary: This work investigates the effect of uniaxial stretching on the properties of neat poly(L-lactide) (PLLA) and miscible PLLA/poly(vinyl acetate) (PVAc) blends. The stretching process influences the thermal properties, crystallization behavior, miscibility, crystal structure, and mechanical properties of the materials. With an increased stretching ratio, the chains in PLLA and PLLA/PVAc blends become more oriented and exhibit enhanced crystallization, resulting in changes in thermal properties and improved toughness. The findings provide insight into the effect of stretching on miscible PLLA blends and offer practical implications for their large-scale application.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Polymer Science
Wenze Li, Mengyao Wang, Huan Luo, Yanhua Niu, Yajiang Huang, Guangxian Li
Summary: This study investigates the crystallization behaviors of stereocomplex and homochiral crystals by blending high molecular weight PLLA with low molecular weight PDLA and its diblock copolymers. It was found that the introduction of different sequences can inhibit the crystallization kinetics of the blends, with the formation of sc crystalites prior to hc ones. Additionally, micro phase separation between PLA and PDMS segments was observed to weaken the competition between sc and hc crystals.
Article
Polymer Science
Suyang Dai, Ni Jiang, Zhenbo Ning, Zhihua Gan
Summary: The length of the PDLA block was found to have a significant impact on the degradation behavior of PLLA/4-DL-D blend films.
POLYMER INTERNATIONAL
(2021)
Article
Crystallography
Xingyuan Diao, Xiaonan Chen, Shihao Deng, Hongwei Bai
Summary: In this study, trace amounts of epoxy-functionalized small-molecule modifiers were introduced into enantiomeric blends during reactive melt-blending to enhance the formation of stereocomplex-type polylactide (SC-PLA). The results showed that the in situ generation of multi-arm stereo-block PLA copolymers significantly improved SC formation, even with only 0.5 wt% modifiers. The unique copolymers acted as compatibilizers, suppressing the separation of the alternately arranged PLLA/PDLA chain segments in the molten state. Furthermore, the generation of these copolymers did not significantly increase the melt viscosity of the blends, suggesting new opportunities for high-throughput processing of SC-PLA materials.
Article
Chemistry, Multidisciplinary
Megha D. Deokar, Baijayantimala Garnaik, Swaminathan Sivaram
Summary: Well-defined six-arm star-branched bio-degradable block copolymers were prepared using controlled ring-opening polymerization and a sequential monomer addition method. The study found that the sequence of enchainment could be changed by reversing the order of monomer addition, resulting in different crystalline or amorphous blocks. However, disruption of the block structure was observed in one of the copolymers due to competing transesterification reactions. Differential scanning calorimetry studies showed interesting phase morphologies in these sequence-controlled block copolymers. Blending these copolymers with a commercially sourced polymer led to improved tensile toughness in the blend.
Article
Polymer Science
Lidong Feng, Xinchao Bian, Gao Li, Xuesi Chen
Summary: The study shows that the compatibility between PLLA and PLDLA-m decreases as the L-lactate unit content in PLDLA-m decreases, impacting the crystallization and compatibility of the blends.
Article
Polymer Science
Martin Boruvka, Cenek Cermak, Lubos Behalek, Pavel Brdlik
Summary: This study focused on characterizing the properties of nanocomposite systems based on asymmetric poly(L-lactide)/Poly(D-lactide) blends with the addition of nano-hydroxyapatite (HA) and 5 wt.% PDLA loading. The results showed that increasing HA content and blending with 5 wt.% PDLA enhanced tensile modulus, crystallinity, and thermal-resistance, while in-mold annealing further improved these properties by achieving a higher degree of crystallinity. However, higher HA content and in-mold annealing resulted in decreased % elongation values at break and tensile strength, as well as caused embrittlement of the material systems.
Article
Biochemistry & Molecular Biology
Fen Ma, Chenguang Jiang, Wenyuan Xie, Defeng Wu
Summary: Using polysaccharide nanocrystals, such as chitin nanocrystals, as nanofillers for biodegradable aliphatic polymers is an attractive method for developing fully degradable nanocomposites. The incorporation of chitin nanocrystals in poly(L-lactide)/poly(D-lactide) blends promotes the formation of stereocomplex crystallites and accelerates overall crystallization kinetics. The nanocomposites exhibit higher stereocomplex crystallization temperatures and lower activation energy compared to the blend. However, the presence of chitin nanocrystals reduces the fraction of stereocomplex crystallites due to the nucleation effect, despite an increased rate of homocrystallization. This study provides valuable information for the use of chitin nanocrystals as nucleators for polylactide stereocomplexes.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Polymer Science
Jun Shao, Lanli Xu, Shouzhi Pu, Haoqing Hou
Summary: Blending PLLA and PDLA and stirring for different times results in products with varying crystallization behaviors. Longer stirring times lead to higher SC content, lower HC content, reduced total crystallinity, and decreased melting temperature for SC and HC. The effect of stirring time diminishes with increasing molecular weights, providing a route to customize the crystallization behavior of PLLA/PDLA specimens.
Article
Polymer Science
Tien-Wei Shyr, Huan-Chieh Ko, Tzong-Ming Wu, Meifang Zhu
Summary: The study found that different storage conditions can lead to varying levels of hydrolysis and degradation in polylactide samples, affecting their thermal stability and crystallization behavior. Hydrolysis results in shortened molecular chains, increased nucleation, decreased melting points, and increased melting enthalpy, impacting the formation of homocrystals in the samples.
Article
Polymer Science
Beata Misztal-Faraj, Marcelina Ciupak, Ryszard Pecherski, Leszek Jarecki
Summary: The study analyzes the development of polymorphic composition in the isothermal crystallization process of unstressed amorphous PLLA, and predicts the relationship between the transformation degree of individual polymorphs and crystallization temperature as well as the overall transformation degree.
Article
Materials Science, Multidisciplinary
Ju Yao, Zhen Zeng, Hongwei Bai, Qin Zhang, Qiang Fu
Summary: In asymmetric poly(L-lactide)/poly(D-lactide) blends, achieving high-efficient formation of finely dispersed stereocomplex crystallites can be challenging due to competition between stereocomplexation and chain mixing. Pre-mixing PLLA and PDLA chains can lead to decreased formation efficiency of SC particles, despite smaller particle size. Direct mixing at lower temperatures is more effective for constructing SCs with superior nucleation efficiency, compared to common melt-processing conditions.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Ju Yao, Zhen Zeng, Hongwei Bai, Qin Zhang, Qiang Fu
Summary: Efficient formation of finely dispersed stereocomplex crystallites can be achieved through a unique melt-mixing procedure, but the introduction of premixed chains may significantly decrease the quantity of SCs particles formed, despite smaller particle size.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2021)
Article
Chemistry, Applied
Yaowalak Srisuwan, Yodthong Baimark
Summary: This paper reports a study on flexible polymer blends made from PLLA-PEG-PLLA and TPS. The addition of TPS suppressed crystallizability of PLLA and PLLA-PEG-PLLA matrices, while greatly increasing the thermal stability of PLLA-PEG-PLLA. The PEG middle-blocks enhanced phase compatibility between PLLA-PEG-PLLA and TPS, resulting in ductile and flexible blend films.
CARBOHYDRATE POLYMERS
(2022)
Article
Polymer Science
Hongwei Zhao, Bing Liao, Fuwei Nian, Kun Wang, Ying Guo, Hao Pang
JOURNAL OF APPLIED POLYMER SCIENCE
(2018)
Article
Polymer Science
Hongwei Zhao, Bing Liao, Fuwei Nian, Yangyang Zhao, Kun Wang, Hao Pang
JOURNAL OF APPLIED POLYMER SCIENCE
(2018)
Article
Chemistry, Multidisciplinary
Hongwei Zhao, Yijie Bian, Mingzhi Xu, Changyu Han, Yi Li, Qinglin Dong, Lisong Dong
Article
Polymer Science
Hongwei Zhao, Bing Liao, Kun Wang, Yangyang Zhao, Fuwei Nian, Yeyun Meng, Hao Pang
JOURNAL OF APPLIED POLYMER SCIENCE
(2018)
Article
Chemistry, Physical
Hongwei Zhao, Yijie Bian, Yi Li, Qinglin Dong, Changyu Han, Lisong Dong
JOURNAL OF MATERIALS CHEMISTRY A
(2014)
Article
Polymer Science
Hongwei Zhao, Yancun Yu, Changyu Han, Qingquan Liu, Huan Liu, Guangbin Zhou, Mingzhi Xu
Summary: This study utilized EGA terpolymer to enhance the stereocomplexation and toughness of PLLA/PDLA blends, resulting in increased crystallization rate and improved melt reorganization from HC to SC as EGA mass fraction grew. The addition of EGA also significantly enhanced the toughness of the blend while increasing impact strength.
JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Zhaozhang Deng, Hongwei Zhao, Xinxiu Cao, Shaohui Xiong, Gen Li, Jiyong Deng, Hai Yang, Weijie Zhang, Qingquan Liu
Summary: This study developed a molecular dipole control strategy to modulate the built-in electric field (BEF) in polymeric photocatalysts. A series of conjugated microporous polymers (CMPs) with adjustable BEF were designed and prepared. The optimized CMP, CbzCMP-9, exhibited the strongest BEF, leading to remarkable photocatalytic performance in thiocyano chromones and C-3 thiocyanation of indoles.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Environmental Sciences
Qi Peng, Hongwei Zhao, Guang Chen, Qilin Yang, Xinxiu Cao, Shaohui Xiong, Anguo Xiao, Gen Li, Bo Liu, Qingquan Liu
Summary: In this study, a low-cost magnetic polymer adsorbent was designed to effectively remove silver from waste electronic equipment and anode slime. This adsorbent exhibited superior adsorption capacity and magnetic responsiveness, completing the adsorption process within a short duration and with high selectivity. This research not only provides new guidance for the development of porous polymeric adsorbents, but also offers technical feasibility for the recovery and reutilization of precious metals.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Chemistry, Multidisciplinary
Huan Liu, Zi-yuan Zhou, Shi-han Li, Bing-an Lu, Hong-wei Zhao, Qing-quan Liu
Summary: The research focuses on the design of an organic precursor to control the construction of carbon materials and regulate their functionality. The study found that using mesoporous polymers with Schiff base moieties as precursors resulted in mesoporous carbon with excellent charge storage and transportation abilities.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Hongwei Zhao, Huan Liu, Yaqin Liu, Yong Yang
