scholarly journals The Critical Role of Electron‐Donating Thiophene Groups on the Mechanical and Thermal Properties of Donor–Acceptor Semiconducting Polymers

2019 ◽  
Vol 5 (5) ◽  
pp. 1800899 ◽  
Author(s):  
Song Zhang ◽  
Michael U. Ocheje ◽  
Lifeng Huang ◽  
Luke Galuska ◽  
Zhiqiang Cao ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Critical Role ◽  
Semiconducting Polymers ◽  
Mechanical And Thermal Properties ◽  
Donor Acceptor

scholarly journals Micro and nanocomposites of polybutadienebased polyurethane liners with mineral fillers and nanoclay: thermal and mechanical properties

2017 ◽  
Vol 15 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Pablo Ross ◽  
Germán Escobar ◽  
Guillermo Sevilla ◽  
Javier Quagliano
Keyword(s):  
Thermal Properties ◽  
Polymer Chains ◽  
Toluene Diisocyanate ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mineral Fillers

AbstractMicro and nanocomposites of hydroxyl terminated polybutadiene (HTPB)-based polyurethanes (NPU) were obtained using five mineral fillers and Cloisite 20A nanoclay, respectively. Samples were prepared by the reaction of HTPB polyol and toluene diisocyanate (TDI), and the chain was further extended with glyceryl monoricinoleate to produce the final elastomeric polyurethanes. Mechanical and thermal properties were studied, showing that mineral fillers (20%w/w) significantly increased tensile strength, in particular nanoclay (at 5% w/w). When nanoclay-polymer dispersion was modified with a silane and hydantoin-bond promoter, elongation at break was significantly increased with respect to NPU with C20A. Thermal properties measured by differential scanning calorimetry (DSC) were not significantly affected in any case. The molecular structure of prepared micro and nanocomposites was confirmed by Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Interaction of fillers with polymer chains is discussed, considering the role of silanes in compatibilization of hydrophilic mineral fillers and hydrophobic polymer. The functionalization of nanoclay with HMDS silane was confirmed using FTIR. Microstructure of NPU with C20A nanoclay was confirmed by Atomic Force Microscopy (AFM).

scholarly journals Role of Cured Epoxy and Block Copolymer Addition in Mechanical and Thermal Properties of Polyethylene

2017 ◽  
Vol 20 (5) ◽  
pp. 1221-1229 ◽  
Author(s):  
Bruna Louise Silva ◽  
Bruno Guilherme Christoff ◽  
Carlos Mauricio Lepienski ◽  
Eduardo Lenz Cardoso ◽  
Luiz Antônio Coelho ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Block Copolymer ◽  
Mechanical And Thermal Properties

T and V-shaped donor–acceptor–donor molecules involving pyridoquinoxaline: large Stokes shift, environment-sensitive tunable emission and temperature-induced fluorochromism

2018 ◽  
Vol 54 (14) ◽  
pp. 1786-1789 ◽  
Author(s):  
Bahadur Sk ◽  
Saurabh Khodia ◽  
Abhijit Patra
Keyword(s):  
Critical Role ◽  
Stokes Shift ◽  
Emission Properties ◽  
Large Stokes Shift ◽  
Donor Acceptor ◽  
Tunable Emission

The critical role of molecular shapes in the environment-sensitive and temperature-induced emission properties of pyridoquinoxaline-based donor–acceptor–donor molecules was demonstrated.

Role of Alkali Treatment on Mechanical and Thermal Properties of Bamboo Particles Reinforced Polyvinylchloride Composites

2009 ◽  
Vol 79-82 ◽  
pp. 545-548 ◽  
Author(s):  
Hui Wang ◽  
Tian Lan ◽  
Kui Chuan Sheng ◽  
Xiang Qun Qian ◽  
Rui Chang
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Thermal Properties ◽  
Alkali Treatment ◽  
Alkali Solution ◽  
Mechanical And Thermal Properties ◽  
New Materials ◽  
Maximum Value ◽  
Dsc Curves

In order to illustrate the role of alkali treatment of bamboo particles reinforced polyvinylchloride composites (BPPC), bamboo particles were treated by alkali aqueous solution with a serial concentration of 0.5%, 1%, 2%, 5% and 10%. Mechanical, thermal properties of alkali treated BPPC and micro-micrographs of the fracture surface were researched and compared with raw bamboo particles fabricated BPPC respectively. Results showed that tensile strength of BPPC increased before the solution reached the concentration of 5% and got a maximum value of 15.07MPa at the concentration of 5%. The curve decreased significantly as the concentration of solution went higher as to 10%. Modules of rupture got a highest value of 44.73MPa till reached the concentration of 2% and then decreased. Modules of elasticity increased in the whole before reached the concentration of 5% and the maximum value was 4362.48MPa which was 5 times more than the original bamboo particles. DSC curves illustrated that raw bamboo particles mixed with PVC showed a higher Tg which meant that raw fiber was not well compatible with PVC and BPPC treated with alkali solution performed a better compatibility. According to SEM observations, interface interaction of fiber-matrix that were modified of alkali solution upon bamboo particles appeared a better interlock action correlated to higher mechanical properties and better compatibility between fiber and matrix. Hence, the use of alkali treated bamboo particles as reinforcement was a feasible and competitive method of creating new materials.

The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky
Keyword(s):  
Language Development ◽  
Critical Role ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Children With Asd ◽  
Prevalence Estimates ◽  
Notable Increase ◽  
Screening Assessment ◽  
Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

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