Wingstrand, Sara L.; Shen, Bo; Kornfield, Julie A.; Mortensen, Kell; Parisi, Daniele; Vlassopoulos, Dimitris; Hassager, Ole
Rheological Link Between Polymer Melts with a High Molecular Weight Tail and Enhanced Formation of Shish-Kebabs
Presence of an ultra high molecular weight (UHMw) fraction in flowing polymer melts is known to facilitate formation of oriented crystalline structures significantly. The UHMw fraction manifests itself as a minor tail in the molar mass distribution and is hardly detectable in the canonical characterization methods. In this study, alternatively,…
Structural analysis of mtEXO mitochondrial RNA degradosome reveals tight coupling of nuclease and helicase components
Razew, Michal; Warkocki, Zbigniew; Taube, Michal; Kolondra, Adam; Czarnocki-Cieciura, Mariusz; Nowak, Elzbieta; Labedzka-Dmoch, Karolina; Kawinska, Aleksandra; Piatkowski, Jakub; Golik, Pawel; Kozak, Maciej; Dziembowski, Andrzej; Nowotny, Marcin
The mitochondrial RNA degradosome (mtEXO) plays an essential role in the regulation of mitochondrial gene expression and is composed of the 3′-to-5′ exoribonuclease Dss1 and the helicase Suv3. Here the authors present the RNA bound mtEXO crystal structure and give insights into its…
Disruptive effect of tocopherol oxalate on DPPC liposome structure: DSC, SAXS, and fluorescence anisotropy studies
Neunert, Grażyna; Tomaszewska-Gras, Jolanta; Siejak, Przemyslaw; Pietralik, Zuzanna; Kozak, Maciej; Polewski, Krzysztof
α-Tocopherol oxalate (TO), a tocopherol ester derivative, was investigated for its effect on the structural changes of fully hydrated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes, as a function of concentration and temperature, by applying differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), and DPH fluorescence anisotropy methods. The DSC and DPH…
Anisotropic nanoparticles as templates for the crystalline structure of an injection-molded isotactic polypropylene/TiO2 nanocomposite
Zhang, Peng; Kraus, Tobias
We study the molecular origins of anisotropy in a semicrystalline polymer nanocomposite that is caused by aligned, elongated filler nanoparticles. Our study is based on spatially resolved 2D WAXS/SAXS data that indicates the arrangement of molecules, lamellae, and filler particles in the composite. Isotactic polypropylene (IPP) samples filled with anisotropic…
Effect of high molecular weight on pore formation and various properties of microporous membrane used for lithium-ion battery separator
Xu, Guan; Ding, Lei; Wu, Tong; Xiang, Ming; Yang, Feng
In this article, iPP cast films with high molecular weight in middle layer were prepared to investigate the effect of high molecular weight component on pore formation and mechanical strength. The results of DSC, SEM and 2D-XRD indicated that higher molecular weight and die draw ratio (DDR) would not alter…
Highly Biodegradable and Tough Polylactic Acid–Cellulose Nanocrystal Composite
Muiruri, Joseph K.; Liu, Songlin; Teo, Wern Sze; Kong, Junhua; He, Chaobin
Poly(l-lactide) cellulose nanocrystals-filled nanocomposites were fabricated by blending of cellulose nanocrystals-g-rubber-g-poly(d-lactide) (CNC-rD-PDLA) and commercial PLLA, in which CNC-g-rubber was synthesized by ring opening polymerization (ROP) of d-lactide and a ε-caprolactone mixture to obtain CNC-P(CL-DLA), followed by further polymerization of d-lactide to obtain CNC-rD-PDLA. X-ray…
Bioinspired Polylactide Based on the Multilayer Assembly of Shish-Kebab Structure: A Strategy for Achieving Balanced Performances
Yi, Longfei; Luo, Shanshan; Shen, Jiabin; Guo, Shaoyun; Sue, Hung-Jue
Achieving balanced mechanical performances in a polymer material has long been attractive, but it is still a significant challenge. Herein, a nonadditive strategy was proposed by tailoring the crystalline structure of neat polylactide (PLA) through a layer-multiplying extrusion. Compared with normal PLA, the layer-multiplied material exhibited a 50% increase in…
Effects of Interconnected Polymer Nanopores Leading to Different Degrees of Confined Polymerization
Wang, Kui; Lei, Jinhua; Nie, Heran; Shen, Lu; Chen, Peng; Zhou, Guangyuan
In this study, different degrees of ethylene-confined polymerization (non-confined, slightly confined, and highly confined) are presented in porous polymer microspheres (PPMs) with an interconnected tri-modal pore structure. First, three catalysts, Cp2ZrCl2, Cp2TiCl2, and TiCl4, are attached to the interface of PPMs to form a nano-confined space for ethylene polymerization. Then…
Inter-fibrillar tie chains determined critical stress of large strain cavitation in tensile stretched isotactic polypropylene
Lu, Ying; Lyu, Dong; Xiong, Bijin; Chen, Ran; Men, Yongfeng
Isotactic polypropylene (iPP) samples with pure mesophase, pure α modification, and coexistence of both phases were used to investigate the sudden stress whitening triggered at large strain during stretching. This whitening was caused by the cavities generated in the highly oriented amorphous network. The critical stresses of such cavitation-induced whitening…
High molecular weight poly(butylene succinate-co-furandicarboxylate) with 10mol% of BF unit: Synthesis, crystallization-melting behavior and mechanical properties
Peng, Shuangbao; Bu, Zhiyang; Wu, Linbo; Li, Bo-Geng; Dubois, Philippe
In this study, high molecular weight poly(butylene succinate-co-furandicarboxylate) with 10mol% of butylene furandicarboxylate unit (PBSF10) was synthesized and its crystal structure and crystallization-melting behaviors were investigated by means of WAXD, SAXS, DSC and POM. The tensile properties were also assessed. The crystal structure of PBSF10 is found to be the…