Guseva, M. A.; Gerasin, V. A.; Shklyaruk, B. F.; Dubinskiy, V. A.
Relation between thermal effects and structural changes under deformation of thermoplastics
The article reports thermal effects accompanying deformation of widely used thermoplastics: PE of different density, highly isotactic and stereodefective PP, PA6, PC. A number of structural methods (X-ray diffraction at large and small angles, DSC, IR spectroscopy, microscopy, volume measurements) were used to establish the factors underlying generation of heat…
Radiopaque Highly Stiff and Tough Shape Memory Hydrogel Microcoils for Permanent Embolization of Arteries
Zhang, Yinyu; Gao, Haijun; Wang, Hao; Xu, Ziyang; Chen, Xiaowei; Liu, Bo; Shi, Yuan; Lu, Ying; Wen, Lianfang; Li, Yan; Li, Zhisheng; Men, Yongfeng; Feng, Xuequan; Liu, Wenguang
Transcatheter arterial embolization of aneurysm with metal microcoils is notoriously prone to recanalization arising from the low filling ratio due to their extreme rigidity. Smart hydrogel microcoils with tunable modulus may essentially significantly improve the therapeutic efficacy. Here, a radiopaque highly stiff body-temperature-triggered shape memory (SM) hydrogel is fabricated for…
Processing of PVDF-based electroactive/ferroelectric films: importance of PMMA and cooling rate from the melt state on the crystallization of PVDF beta-crystals
Neef, Alexandre De; Samuel, Cédric; Stoclet, Grégory; Rguiti, Mohamed; Courtois, Christian; Dubois, Philippe; Soulestin, Jérémie; Raquez, Jean-Marie
Poly(vinylidene difluoride) (PVDF) displays attractive ferroelectric/piezoelectric properties and its polar β-crystals are specifically targeted for achieving electroactive applications. However, their direct crystallization from the melt state represents a challenging task that has never been addressed using melt-state processes. The use of poly(methyl methacrylate) (PMMA) is herein investigated…
Precursor non-stoichiometry to enable improved CH3NH3PbBr3 nanocrystal LED performance
Chandran, Bevita K.; Veldhuis, Sjoerd A.; Chin, Xin Yu; Bruno, Annalisa; Yantara, Natalia; Chen, Xiaodong; Mhaisalkar, Subodh
High photoluminescence quantum yields and narrow emission wavelengths, combined with low temperature solution processing, make CH3NH3PbBr3 nanocrystals (NCs) favorable candidates for light-emitting applications. Herein, we describe the synthesis of CH3NH3PbBr3 NC inks by a convenient room-temperature ligand assisted reprecipitation protocol. We further investigate the effect of modulation of the…
Precise inter-lamellar/inter-fibrillar localization and consequent fabrication of porous membranes with crystallization-modulated pore-size
Ye, Cuicui; Zhao, Jinxing; Ye, Lijun; Jiang, Zhiyong; You, Jichun; Li, Yongjin
In poly(vinylidene fluoride)/poly(1,4-butylene succinate) (i.e. PVDF/PBSU) blend, the precise inter-lamellar or inter-fibrillar localization of PVDF crystal lamellae has been achieved. In the specimen with PVDF 70 wt%, comparable PVDF and PBSU volume fractions result in the inter-lamellar structures. When PVDF acts as the minority phase (PVDF 30 wt%), its crystal lamellae locate…
Polysaccharide and poly(methacrylic acid) based biodegradable elastomeric biocompatible semi-IPN hydrogel for controlled drug delivery
Ganguly, Sayan; Maity, Priti Prasanna; Mondal, Subhadip; Das, Poushali; Bhawal, Poushali; Dhara, Santanu; Das, Narayan Ch.
Nanoparticles embedded semi-interpenetrating (semi-IPNs) polymeric hydrogels with enhanced mechanical toughness and biocompatibility could have splendid biomedical acceptance. Here we propose poly(methacrylic acid) grafted polysaccharide based semi-IPNs filled with nanoclay via in situ Michael type reaction associated with covalent crosslinking with N,N-methylenebisacrylamide (MBA). The effect of…
Polyurethane with an ionic liquid crosslinker: a new class of super shape memory-like polymers
Behera, Prasanta Kumar; Mondal, Prantik; Singha, Nikhil K.
This investigation reports on the synthesis of a new class of ionic liquid crosslinked shape-memory polyurethane (PU-IL) based on polycaprolactone diol and 4,4′-methylenebis(phenyl isocyanate) (MDI), which can overcome the major drawbacks of conventional shape-memory polyurethanes. In this case, the ionic liquid crosslinker in PU-IL exhibited not only a higher shape-recovery…
Poly(neopentyl glycol 2,5-furandicarboxylate): A Promising Hard Segment for the Development of Bio-based Thermoplastic Poly(ether-ester) Elastomer with High Performance
Chi, Dequan; Liu, Fei; Na, Haining; Chen, Jing; Hao, Chuncheng; Zhu, Jin
With a high melting temperature and good crystallization ability, poly(neopentyl glycol 2,5-furandicarboxylate) (PNF), a polyester derived from bio-based 2,5-furandicarboxylic acid and neopentyl glycol, has been proposed and proved to be a promising hard segment for the development of novel bio-based thermoplastic poly(ether-ester) elastomer (TPEE). The resulting TPEE, namely PNF–PTMG, has…
Poly(ether ether ketone) grafted with sulfoalkylamine for highly sensitive humidity sensor with small hysteresis
Shao, Zhi; Zhuang, Zhuang; Lin, Haidan; Zhao, Chengji
Here, a series of novel poly(ether ether ketone) containing sulfoalkylamine pendant groups (SNPEEK-x) were synthesized by grafting copolymerization reaction. The chemical structure of SNPEEK-x was identified by 1H NMR and the morphology of all films was measured by SAXS and TEM. The impedance varied for five orders of magnitude (from…
Photo-responsive liquid crystals derived from azobenzene centered cholesterol-based tetramers
Gupta, Monika; Pal, Vaibhav; Pal, Santanu Kumar
This paper demonstrates the design and synthesis of azobenzene centred cholesterol based tetramers. A series of eight oligomeric compounds with varying flexible alkyl spacers (n = 1–8) is reported. These compounds displayed enantiotropic and monotropic chiral nematic (N*) mesophases, which were characterized by polarized optical microscopy (POM), differential scanning calorimetry…