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One acetylenic monomer (APCB) containing carborane with extremely thermal and thermo-oxidative stability was synthesized and used as the thermal copolymerization component with acetylene-terminated imide monomer (m-EFDA) to improve the thermal and thermo-oxidative stability of the polyimide materials. The curing behavior of the blends of imide monomer and APCB was investigated by FT-IR and DSC. Rheometer...
High thermally and thermo-oxidatively stable poly(phenylene-carborane) (PPB) was synthesized via Ni(0)-catalyzed polymerization of bis(aryl chloride) monomer containing carborane. This polymer was soluble in THF and NMP at room temperature, thus allowing molecular weight and spectroscopic analysis. Number-average molecular weight determined by 1H-NMR spectroscopy was 5.4 × 103 g/mol. The crystalline...
Field assisted quantum tunneling composite (FAQTC) is a unique pressure-sensitive material with the advantages of large resistance change range under external force, easy preparation and excellent mechanical properties. In this paper, with attentions to the pressure-sensitivity of the FAQTCs, the effects of silicon rubber matrix, diameter and dosage of nickel particles as well as magnetic field treatment...
We sought to identify an evident enthalpic-driven transition below an entropic-driven closed-loop phase transition by studying the phase behavior in miscible binary block copolymer (BCP) blends of a polystyrene-b-poly (n-butyl methacrylate) (PS-b-PnBMA) and a deuterated polystyrene-b-poly (n-hexyl methacrylate) (dPS-b-PnHMA), using small-angle x-ray scattering (SAXS) and depolarized light scattering...
New diamines for high-performance poly(ester imide)s (PEsIs) containing dimethyl groups at the ortho-position of amino groups and ester derivatives have been developed to improve optical transparency and glass transition temperature (Tg) while maintaining a low coefficient of thermal expansion (CTE). Four kinds of PEsIs derived from bis(4-amino-3,5-dimethylphenyl) terephthalate (BADMT) and aromatic...
Polydopamine (Pdop) is coated on copper mesh (Cu mesh/Pdop). Upon heat treatment of the Cu mesh/Pdop, Pdop particles are newly formed at the surface of the Cu mesh/Pdop, which is used as a superhydrophilic mesh. After octadecylamine (ODA) is coated on the heat-treated Cu mesh/Pdop, hierarchical and strong ODA crystals are formed by special interactions between the ODA and the Pdop. The surface morphologies...
An advanced analytic method, based mainly on thermorheological analysis of standard frequency sweeps at several temperatures, is introduced which can determine a host of rheological indicators for long-chain branched polyethylenes and other materials with an Arrhenius-type temperature dependence. The method can be used to classify and categorize unknown samples to material types (tubular and autoclave...
The macroscopic alignment of conjugated polymers with low grain boundary is essential to carrier transport. We investigated the formation mechanism of the aligned films of the donor−acceptor copolymer of 3,6-bis(thiophen-2-yl)-N,N′-bis(2-octyl-1-dodecyl)-1,4-dioxo-pyrrolo [3,4-c]pyrrole and thieno- [3,2-b]thiophene (PDBT-TT) by solvent vapor enhanced drop-casting (SVE DC). The dichroic ratio (DR)...
Poly(l-lactic acid)-poly(ethylene glycol)-poly(l-lactic acid) (PLLA-PEG-PLLA) and poly(d-lactic acid)-poly(ethylene glycol)-poly(d-lactic acid) (PDLA-PEG-PDLA) triblock copolymers having relatively high molecular weights (Mn > 60 kDa) and different lengths of PEG midblock (2–20 kDa) and PLLA, PDLA end blocks (20–45 kDa for each block) were prepared and blended in equal mass. The competing crystallization...
The copper catalyzed Ullmann polymerization is rarely used in polymer chemistry filed owing to the covered mechanism and insufficient conversion. Herein, we present the development of an efficient Ullmann CN coupling polymerization route to synthesize conjugated Donor-Acceptor (D-A) polymers containing thiophene-phthalazinone moiety. The model reactions were carried out to investigate varies solvents,...
In order to investigate the effect of the ratio of donor (D) and acceptor (A) in conjugated D-A polymers on the photovoltaic properties and photodetector performance, a series of polymers containing a weak electron donor of thiophene (T) and a strong electron acceptor of pyrrolo [3,4-c]pyrrole-1,4-dione (DPP) were designed and synthesized. Five polymers P1–P5 were obtained with different D/A (T/DPP)...
Polyphenylenesulfone (PPSU) is widely used as a membrane material for water reuse applications because of its good chemical resistance, hydrolysis stability and outstanding mechanical strength. However, due to its hydrophobic nature, fouling and relatively low water permeability are potential drawbacks of PPSU membranes. Sulfonation of PPSU could significantly improve the hydrophilicity but compromise...
In this work, multiple transitions from isothermally crystallized poly(3-hexylthiophene) (P3HT) and their correlations to the structure were investigated. It was discovered that high and low temperature crystallites of varying degree orders can be formed in P3HT matrices during the isothermal crystallization. The high temperature crystallite was highly ordered crystalline form having melting temperature...
A feasible approach is proposed to enhance the ability of stereocomplex (SC) crystallization and depress the homocrystallization in high-molecular-weight (HMW) poly(l-lactic acid)/poly(d-lactic acid) (PLLA/PDLA) racemic blends by miscible polymer blending with hydrogen bond interactions. Poly(vinyl phenol) (PVPh) is selected as a model polymer and blended with PLLA and PDLA at different compositions...
Probing depth dependent deformation at nano- and micrometer length scales has been observed in indentation experiments of polymers. Unlike in metals, where size effects are observed in plastic deformation and are attributed to geometrically necessary dislocations, the origin of size dependence in polymers is not well understood. As classical continuum theories are unable to describe such phenomena,...
We demonstrated the crystallization assisted microphase separation of all-conjugated diblock copolymers poly (2,5-dihexyloxy-p-phenylene)-block-(3-hexylthiophene) (PPP-b-P3HT, denoted as BmTn). The crystallization and microphase separation are summarized in terms of the difference of aggregation in solvent and the crystallization temperatures of two blocks, respectively. B39T18 and B41T44 were selected,...
Conjugated polymers using 6-(2-thienyl)-4H-thieno[3,2-b]indole (TTI) and isoindigo (ID) were synthesized and applied to the polymer solar cells. TTI as electron pushing unit and ID as electron pulling unit were incorporated in the push–pull types of conjugated polymers (PTTIID, PTTIID-3, PTTIID-5 and PTTIID-7). The alternating copolymer with TTI and ID units was synthesized in addition to the corresponding...
Uniform fibers composed of two concentrations of poly(vinyl alcohol) (PVA) separately reinforced with up to 20 wt% cellulose nanocrystals (CNCs) were successfully produced by electrospinning. The CNCs were well dispersed in both 5 wt% PVA (5PVA) and 7 wt% (7PVA) aqueous solution prior to nanofiber manufacture. Composite nanofibers with controllable ultra-thin diameters of around 200 nm were generated...
We successfully synthesized plasma-polymerized films from a highly crosslinkable monomer, dicyclopentadiene (a norbornene derivative), using a low-temperature plasma process as an anti-corrosion coating for Cu metal plates. Plasma-enhanced deposition of polymer films from a dicyclopentadiene precursor was carried out using radio frequency (13.6 MHz) plasma generation with argon or nitrogen carrier...
Four kinds of mannitol-based ketal-linked porous organic polymers (MKPOPs) were successfully synthesized through condensation reaction between aromatic acetyl monomers and mannitol, catalyzed by p-toluenesulfonic acid. The structure of resulting polymers was confirmed by Fourier transform infrared and solid-state 13C nuclear magnetic resonance spectrum measurements. The porosities of MKPOPs were investigated...
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