Article
Polymer Science
Sanchayan Pal, Rajiv K. Srivastava, Bhanu Nandan
Summary: The study revealed that the crystalline structure and morphology of PEO/PBA blends are governed by the faster crystallization kinetics of PEO and the higher nucleation density of PBA, showcasing a novel insight into the competitive role of crystallization rate and nucleation density in crystalline/crystalline blends.
Article
Multidisciplinary Sciences
Yuting Zhou, Joaquin Rodriguez-Lopez, Jeffrey S. Moore
Summary: Post-consumer plastic waste has prompted the development of deconstruction methods to recover valuable substances, but depolymerization of highly crystalline engineering thermoplastics remains challenging. In this study, the authors demonstrate the electrochemical depolymerization of polyoxymethylene into repolymerizable monomer under ambient conditions. Through various experiments, they uncover the heterogeneous electro-mediated acid depolymerization mechanism and the dual role of the co-solvent HFIP. This research highlights the potential of electromediated depolymerization in sustainable chemistry by merging renewable energy and circular plastic economy concepts.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Emre Tekay
Summary: Thermally-triggered shape memory polymers (SMPs) can change shape when exposed to heat. Blending PEO and SIS thermoplastic elastomers resulted in a 60PEO/40SIS blend with the best shape memory performance, showing 95.74% shape fixing and 98.98% shape recovery. The presence of semi-crystalline PEO improved shape fixing, while SIS content enhanced shape recovery capability, despite the immiscibility of these polymers.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2021)
Article
Chemistry, Multidisciplinary
Marvin Langlais, Nicolas Baulu, Severin Dronet, Charlotte Dire, Francois Jean-Baptiste-dit-Dominique, David Albertini, Franck D'Agosto, Damien Montarnal, Christophe Boisson
Summary: Block copolymers based on polyethylene (PE) and ethylene butadiene rubber (EBR) were synthesized using successive controlled coordinative chain transfer polymerization (CCTP). By employing a complex of {Me2Si(C13H8)(2)Nd(BH4)(2)Li(THF)}2 and n-butyl, n-octyl magnesium (BOMAG) as the alkylating and chain transfer agent (CTA), EBR-b-PE diblock copolymers were obtained. Furthermore, triblock and multiblock copolymers featuring highly semi-crystalline PE hard segments and soft EBR segments were synthesized with the development of a bimetallic CTA, pentanediyl-1,5-di(magnesium bromide) (PDMB). These new block copolymers form lamellar structures through crystallization-driven organization and exhibit various mechanical properties, including excellent extensibility and elastic recovery for triblock and multiblock copolymers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Eider Matxinandiarena, Agurtzane Mugica, Manuela Zubitur, Viko Ladelta, George Zapsas, Dario Cavallo, Nikos Hadjichristidis, Alejandro J. Muller
Summary: The morphology and crystallization behavior of two triblock terpolymers composed of polymethylene, equivalent to PE, PEO, and PCL were studied. The sequence of crystallization starting with the PE block, followed by the PCL block, and ending with the PEO block was determined. The tricrystalline nature of these materials was confirmed through a combination of DSC, WAXS, and PLOM experiments.
Article
Polymer Science
Zi-Li Zheng, Wen-Jing Sun, Xi-Xi Zhang, Zhou-Yun-Tong Liu, Wen-Bin Wang, Meng-Han Bai, Hao-Ran Yang, Gan-Ji Zhong, Jia-Zhuang Xu, Zhong-Ming Li
Summary: The interfacial crystallization of polyoxymethylene/poly(butylene succinate) blends induced by polyamide 6 (PA6) fiber was investigated. The PA6 fiber exhibited strong heterogeneous nucleating ability, generating dense nuclei on its surface and compelling the growth of twisted lamellae perpendicular to the fiber. This resulted in the formation of unique interfacial banded transcrystallization. The nucleation density and architecture of the banded transcrystallization were influenced by the crystallization temperature, with higher temperatures leading to decreased nucleation density and transformed stripe patterns.
CHINESE JOURNAL OF POLYMER SCIENCE
(2022)
Article
Polymer Science
Yaping Ma, Aihua He, Chenguang Liu
Summary: Blending isotactic polybutene-1 (PB) with isotactic polypropylene (PP) is an effective strategy to improve the mechanical properties and promote polymorphous transformation of PB. In this study, it was found that adding 2.5 wt% of PB-b-PP copolymer as a compatibilizer in PB/PP/PB-b-PP blends can achieve the most stable phase morphology and enhance the crystallization rate and crystallinity of PB and PP. Copolymer A is more efficient in accelerating the crystallization rate of PP compared to copolymer B, leading to significantly improved mechanical properties of the blends.
Article
Polymer Science
Prasong Srihanam, Yaowalak Srisuwan, Theeraphol Phromsopha, Apirada Manphae, Yodthong Baimark
Summary: In this study, the phase compatibility and mechanical properties of flexible poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA)/thermoplastic starch (TPS) blends were improved by adding citric acid (CA) as a compatibilizer. The crystallinity of PLLA-PEG-PLLA matrix was suppressed and the thermal stability was enhanced by CA modification of TPS. The compatibility between TPS and PLLA-PEG-PLLA phases was improved, and the blends exhibited increased tensile strength, elongation at break, and Young's modulus with higher CA content.
Article
Polymer Science
Nantina Moonprasith, Mizuki Tatsumichi, Kodai Nakamura, Takumitsu Kida, Kyoko Tsubouchi, Tatsuhiro Hiraoka, Masayuki Yamaguchi
Summary: Exposure to shear flow in a pressure-driven capillary rheometer can create concentration gradients without phase separation in miscible polymer blends. Surface enrichment of PMMA in the extruded strand is enhanced when the molecular weight of PMMA is low, and is also influenced by temperature and shear rate. Die length, however, has minimal effect on the segregation behavior. This phenomenon is important for modifying the surface properties of various products.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Wasana Nonkrathok, Tatiya Trongsatitkul, Nitinat Suppakarn
Summary: In this study, the shape memory properties of poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG) blends were improved by adding maleic anhydride-grafted poly(lactic acid) (PLA-g-MA) as a compatibilizer. The PLA-g-MA improved interfacial adhesion between phases and promoted chain entanglement, leading to enhanced mechanical properties and shape fixity performance. The compatibilized blend containing 2 wt% PLA-g-MA exhibited the best shape fixity and recovery performance.
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
Aniket Raje, Prokopios Georgopanos, Joachim Koll, Jelena Lillepaerg, Ulrich A. Handge, Volker Abetz
Summary: The study used foam extrusion to produce highly porous foams from a blend of polyethersulfone (PESU) and poly(ethylene glycol) (PEG), reducing the processing temperature by approximately 100°C and achieving energy efficiency and sustainability. The resulting extruded polymer foam had a porosity of approximately 51% and an average foam cell diameter of 5 μm.
Article
Polymer Science
Neel J. Shah, Sajjad Dadashi-Silab, Michael D. Galluzzo, Saheli Chakraborty, Whitney S. Loo, Krzysztof Matyjaszewski, Nitash P. Balsara
Summary: The study investigated the impact of salt addition on a diblock copolymer system with a negative Flory-Huggins interaction parameter, chi. It was found that ordered phases only appear under specific conditions, as predicted by ionic self-consistent field theory.
Article
Polymer Science
Azamat Slonov, Ismel Musov, Azamat Zhansitov, Azamat Khashirov, Aslanbek Tlupov, Khasan Musov, Elena Rzhevskaya, Irina Fomicheva, Andrey Potapov, Svetlana Khashirova
Summary: The use of polyolefin blends, such as polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA), in 3D printing can help reduce the problems associated with high crystallization rates, such as shrinkage and warpage. Increasing the EVA content in the blend can decrease the crystallization rate of PE and improve the impact strength and processability of the printed objects.
Article
Polymer Science
Panagiotis A. Klonos, Maria Lazaridou, Christina Samiotaki, Apostolos Kyritsis, Dimitrios N. Bikiaris
Summary: This study investigates the thermal transitions, crystallization, and molecular mobility of a series of sustainable polymeric blends based on poly(lactic acid) (PLA) and poly(ethylene adipate) (PEAd). The addition of PEAd to PLA enhances the plasticization of PLA chains and facilitates the nucleation of PLA, leading to strong cold crystallization. The blends also exhibit partially miscible polymers and systematic alternation in both local dynamics and dielectric strength. These PLA/PEAd blends have the potential to be used as phase change materials for tuning material performance.
