Article
Polymer Science
Xian Zhang, Shicheng Zhao, Shiao-Wei Kuo, Wei-Cheng Chen, Mohamed Gamal Mohamed, Zhong Xin
Summary: The study synthesized zinc bicyclo [2.2.1]-heptane-2, 3-dicarboxylate-double-decker silsesquioxanes (Zn2(DDSQ-ND)) for the first time and investigated its effect as a novel and effective nucleating agent in the crystallization behavior of isotactic polypropylene (iPP). The results showed that Zn2(DDSQ-ND) accelerated the formation of ?-phase iPP and acted as a novel ?-nucleating agent in the iPP system.
Article
Polymer Science
Yoshitomo Furushima, Christoph Schick, Akihiko Toda, Hideaki Takahashi, Toshiumi Tatsuki, Satoshi Fujiwara, Kazuma Okada, Masatoshi Ohkura
Summary: Fast scanning calorimetric experiments were conducted to investigate the effect of pre-nucleation on the crystallization and melting kinetics of low-isotacticity polypropylene (LT-PP). The presence of crystal nuclei accelerated the isothermal crystallization rate of LT-PP, but had no effect on the melting kinetics of secondary crystallized LT-PP. Moreover, increasing amounts of crystal nuclei resulted in a decrease in the maximum primary crystallization, which can be attributed to the formation of uncrystallizable defects between the crystalline domains.
Article
Polymer Science
Akihiko Toda
Summary: The crystallization kinetics of poly(butylene terephthalate) under high supercooling was investigated using Temperature-Modulated Fast Scanning Calorimetry (TM-FSC). The study found a temperature dependence of crystal growth rate and compared it with the peak time of heat flow during isothermal crystallization. The crystal growth rate was found to be practically determined by a mobility factor near the glass transition.
Article
Thermodynamics
Qian Ding, Hao Fu, Chaoran Hua, Xinman Jiang, Jia Yu, Keming Zhu
Summary: This study investigates the crystallization behavior, melting characteristics, and semicrystalline morphologies of wollastonite-filled recycled polypropylene (R-PP) composites with and without beta-nucleating agent. The addition of beta-nucleating agent can significantly increase the beta-phase content in wollastonite-filled R-PP composites, providing an effective method for achieving high value-added and low-cost recycling of R-PP.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Materials Science, Ceramics
Khalissa Ariane, Aitana Tamayo, Abdellah Chorfa, Fausto Rubio, Juan Rubio
Summary: The crystallization behaviors, mechanical and optical properties of fluormica glass-ceramic system without and with P2O5 as nucleating agent are studied. The addition of P2O5 changes the crystallization mechanism and morphology of the glass-ceramic, resulting in the formation of flower-like crystals. The transmittance of the glass-ceramic is still about 85% with the incorporation of P2O5.
CERAMICS INTERNATIONAL
(2023)
Article
Polymer Science
Yue Yin, Yuan Wang, Linghui Meng
Summary: In this study, the similar terephthalate structure between UIO-66 and PET was utilized to improve compatibility, while the exposed Zr4+ by defects of UIO-66 was utilized to enhance the interaction between PET and UIO-66. The PET nanocomposites with different contents of UIO-66 showed significantly increased crystallization rate and tensile strength compared to pure PET, with a higher crystallization temperature in the PET-UIO66-1 nanocomposite.
Article
Polymer Science
Yodthong Baimark, Prasong Srihanam, Yaowalak Srisuwan, Theeraphol Phromsopha
Summary: The stereocomplex polylactide (scPLA) powder showed great potential as an effective nucleating agent for improving the crystallization properties of high-molecular-weight poly(L-lactide) (HMW-PLLA) bioplastic.
Article
Engineering, Environmental
Ruru Huang, Yane Zhang, Aimin Xiang, Songbai Ma, Huafeng Tian, Yuge Ouyang, A. Varada Rajulu
Summary: SEM, DSC, and XRD were used to investigate the influence of talc on the crystallization properties and morphology of PVA/talc composite films. The addition of talc improved the crystallinity of PVA and regulated the crystallization rate and uniformity of wafer thickness.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2022)
Article
Polymer Science
Xia Gao, Shunxin Qi, Bo Yang, Yunlan Su, Jing Li, Dujin Wang
Summary: Addition of plasticizer PEG and nucleating agent TMC in PLA matrix can tailor the crystallization behavior of FFF-printed PLA parts. At a bed temperature of 60 degrees C, PEG showed a stronger effect on crystallization behavior compared to TMC, leading to an increase in crystallinity. Shear-induced crystal structures had negligible influence on the final crystallinity of PLA parts.
Article
Polymer Science
Li Qian, Yaxian Wang, Ying Lu, Yongfeng Men
Summary: Research on the crystallization behaviors of two impact copolymer polypropylenes (ICP) revealed differences in their crystallization peaks at different cooling rates, with ICP-A and ICP-B showing distinct behaviors. These differences can be attributed to their different chain microstructures.
Article
Polymer Science
Yujing Tang, Yaqiao Wang, Shihong Chen, Xiangdong Wang
Summary: In this study, branched PLLA was obtained by mixing linear PLLA with a chain extender, and the crystallization properties were further modified by adding self-assembled nucleating agent. The results showed that TMC-300 was an effective nucleating agent for branched PLLA, and its self-assembled fibers provided numerous nucleation sites for improved crystallinity. An appropriate content of TMC-300 could be self-assembled into a fiber network framework to regulate the crystallization behavior of branched PLLA and increase storage modulus. This study is important for low-density microcellular foaming and the preparation of high-quality microcellular foams.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Materials Science, Ceramics
Dongfeng He, Hui Ma, Hao Zhong
Summary: This study investigated the effects of different nucleating agents on MAS glass-ceramics, with the composite nucleating agent showing the best performance.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Multidisciplinary
Dinar Balkaev, Vadim Neklyudov, Valentina Starshinova, Mikhail Stolov, Liliya M. Amirova, Anna Ziyatdinova, Rustem R. Amirov
Summary: This study demonstrates that the dicalcium salt of HEDP can be used as a nucleating agent for iPP, showing increased crystallinity and flexural modulus. The synthesis of this novel nucleating agent is simple, environmentally friendly, and cost-effective.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Engineering, Chemical
Xincheng Guo, Yao Chen, Jianbing Guo, Jun Qin, Honglin Lian, Zongcheng Lu, Xiaolang Chen
Summary: The content ratio of layered double hydroxide (LDH) and beta-nucleating agent (CaHA), mechanical properties, and crystallization behaviors of PP/ethylene vinyl acetate copolymer (EVA)/LDH ternary composites are investigated. The highest notched impact strength is achieved in the 6PEL2 sample with CaHA of 0.03 phr and LDH of 5.70 phr, which is about 100% higher than that of pure PP. This is attributed to the highest relative content of beta-crystals in 6PEL2 and the formation of a large number of cavities absorbing the impact energy.
POLYMER ENGINEERING AND SCIENCE
(2023)
Article
Polymer Science
Ying Wu, Shuo Zhang, Shuqing Han, Kesong Yu, Linyan Wang
Summary: In this study, a crystal nucleating agent was introduced into poly (lactic acid) (PLA) system to improve its foamability and mechanical properties. The results showed that the crystal nucleating agent greatly promoted PLA crystallization, and by controlling the crystallization process, PLA foams with controllable cell structures and high compression properties were obtained.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Polymer Science
Wang-Kai Xiang, Qing Xie, Shan-Shan Xu, Chen-Xuan Sun, Cheng-Tao Yu, Ying Zheng, Peng-Ju Pan
Summary: Stereocomplex crystallization is an effective method to improve the physical properties of stereoregular polymers. This study investigates the effects of PDLA fraction and crystallization temperature on the crystallization kinetics and polymorphic crystalline structure using asymmetric blends of PLLA and PDLA. The results show that a high PDLA fraction and low temperature favor the crystallization of beta-form homocrystals.
CHINESE JOURNAL OF POLYMER SCIENCE
(2022)
Review
Polymer Science
Shanshan Xu, Jian Zhou, Pengju Pan
Summary: This work summarizes important advances in research on both non-crystallizable and crystallizable polymers regarding their stretching behavior near T-g. Through case studies on typical examples, the review systematically presents structural changes, including chain orientation/relaxation kinetics, dynamic network evolution, and stretch-induced phase transition. A discussion on the influence of these structural evolutions on essential end-use properties of materials is also included, aiming to provide guidance for future stretching-related studies.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2022)
Article
Polymer Science
Jian Zhou, Shanshan Xu, Ying Zheng, Chengtao Yu, Guorong Shan, Yongzhong Bao, Pengju Pan
Summary: This study investigated the multistage structural ordering of glassy polymers and the related mechanisms during stretching below T-g, with a focus on the roles of chain orientation and conformational transition. It was found that the orientation of polymer chains and the stacking of phenylene rings induced the generation of a mesomorphic phase, which further transformed into a crystalline phase. Stretching at different temperatures led to varying degrees of mesomorphic phase ordering and facilitated crystallization. The unloading-induced crystallization of stretched PTT was shown to originate from trans-gauche conformational transition.
Article
Polymer Science
Ying Zheng, Navin Kafle, Derek Schwarz, James M. Eagan, Shigetaka Hayano, Yuki Nakama, Pengju Pan, Toshikazu Miyoshi
Summary: This study investigates the molecular dynamics and phase structure of a cocrystal consisting of fixed and mobile polymer crystals using solid-state nuclear magnetic resonance (NMR) spectroscopy. It is found that the mobile component undergoes large amplitude motions associated with crystal-crystal transition, while the fixed component remains rigid in the cocrystal. Asymmetric molecular dynamics leads to nanosegregations of mobile- and fixed-rich domains in the cocrystal, similar to phase separation in miscible polymer blends, but limited to two dimensions due to the packing and connectivity in the cocrystal.
Article
Polymer Science
Lingling Ni, Shanshan Xu, Chenxuan Sun, Yanan Qin, Ying Zheng, Jian Zhou, Chengtao Yu, Pengju Pan
Summary: This study focuses on the role of chain entanglement in polymorphic crystallization and crystal phase transition of polymers. By preparing samples with different entanglement degrees, it is found that chain disentangling can suppress the crystallization kinetics but promote the phase transition rate and degree. This work advances the understanding of the formation and transition mechanisms of polymorphic polymer crystals at the molecular level.
Article
Chemistry, Multidisciplinary
Wenhua Yuan, Chengtao Yu, Shanshan Xu, Lingling Ni, Wenqing Xu, Guorong Shan, Yongzhong Bao, Pengju Pan
Summary: This paper introduces a new principle for achieving self-evolution through programmable crystal transition, proposing a method for developing self-evolving materials. These materials can encode information through crystal phase transition without relying on hydrogels, exhibiting autonomous characteristics.
MATERIALS HORIZONS
(2022)
Article
Chemistry, Applied
Chao Lin, Pengju Pan, Guorong Shan, Miao Du
Summary: Poly(ethylene glycol)-b-poly(epsilon-caprolactone) diblock copolymers (PEG-b-PCL) with predesigned hydrophilic/hydrophobic block length ratios were synthesized and self-assembled into micelles for emulsifying medium-chain triglycerides with an aqueous phase. The relationship between the wettability of the copolymer micelles and their emulsification properties was proved, and various Pickering emulsions, including double-W/O/W emulsions, were controllably prepared through one-step homogenization. The double microstructure of W/O/W Pickering emulsion was demonstrated to be highly stable during long-term storage.
Article
Polymer Science
Dayang Yu, Guoliang Mao, Wenshuo Wang, Huaixun Cai, Shuhua Wang, Pengju Pan, Yongzhong Bao
Summary: The synthesis of PDD-TFE copolymers with precise chemical structures and the study of its effects on condensed matter structures and optical properties are important for their application. The incorporation of PDD monomer into the copolymers increases steric energies, glass transition temperatures, and transparency, while decreasing refractive indexes. These copolymers have potential applications in optical fibers and semiconductors.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Yucheng He, Dan Liu, Jiping Wang, Pengju Pan, Wenbing Hu
Summary: This study investigates the crystallization kinetics and crystal polymorphism of PLA blends with different molecular weights using Flash DSC measurement and confocal Raman spectroscopy. The results show that high molecular weights affect the crystal morphology and suppress the nucleation rates of stereocomplex crystals, resulting in the dominance of homocrystals.
Article
Polymer Science
Shanshan Xu, Chenxuan Sun, Wenhua Yuan, Jian Zhou, Wenqing Xu, Ying Zheng, Chengtao Yu, Pengju Pan
Summary: This study demonstrates the critical role of intermolecular interactions in the physical ageing behavior of polymer glasses. Blending asymmetric poly(lactic acid) (PLA) reduces chain mobility and leads to the formation of a stiffer chain network. The work sheds light on the mechanism underlying the evolution of properties in glassy polymers.
Article
Polymer Science
Mengru Ding, Wenhua Yuan, Shanshan Xu, Chengtao Yu, Ying Zheng, Jian Zhou, Guorong Shan, Yongzhong Bao, Pengju Pan
Summary: Programming the spatial distribution of crystal size in polymers allows the fabrication of multifunctional materials with diverse properties and applications, such as rewritable polymer paper.
Article
Polymer Science
Yucheng He, Dan Liu, Kefeng Xie, Wenqing Xu, Pengju Pan, Wenbing Hu
Summary: The relaxation of structure in poly(lactic acid) blends promotes crystal nucleation, and the annealing at different temperatures has different effects on the nucleation process.
Article
Polymer Science
Jianfei Xia, Shanshan Xu, Ying Zheng, Jian Zhou, Chengtao Yu, Guorong Shan, Yongzhong Bao, Pengju Pan
Summary: This study systematically investigates the effect of comonomer defects on the crystalline structure and phase transition behavior of copolyamides. The results show that the copolyamides exhibit composition-dependent Brill transition temperatures, with a pseudoeutectic characteristic in the intermediate composition range. The copolyamides with pseudoeutectic compositions undergo an irreversible Brill transition, with the γ phase remaining unchanged upon cooling from melt. The γ-alpha transition of pseudoeutectic copolyamides is found to be temperature-dependent.
Article
Polymer Science
Chenxuan Sun, Xuekuan Ma, Lingling Ni, Mengru Ding, Jianfei Xia, Ying Zheng, Chengtao Yu, Bao Wang, Pengju Pan
Summary: Side substitution is an effective method for the chemical modification of linear polyesters, and the presence of side groups has a profound effect on the crystalline structure and phase transition of semicrystalline polyesters. This study synthesized polyesters with different side groups and investigated the effects of these groups on the crystal polymorph and phase transition of the substituted polyesters.
Article
Chemistry, Multidisciplinary
Ying Zheng, Shanshan Xu, Chengtao Yu, Pengju Pan
Summary: This article summarizes recent advances in SC crystallization and stereocomplexed materials of polylactic acid (PLA), including various approaches for controlling the polymorphic crystallization structure and the preparation of different types of stereocomplexed materials. These stereocomplexed materials exhibit excellent physical properties and can be further functionalized. Through this research, a practical platform has been established to uncover the relationships between crystalline structure, physical properties, and functions of stereocomplexed materials.
ACCOUNTS OF MATERIALS RESEARCH
(2022)