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Molecular modeling was utilized to provide insight into the yielding behavior and poor recovery from applied strain for cellulose. Amorphous cellulose models were successfully built and examined with the use of force field pcff_300_1.01. High-temperature molecular dynamics, followed by minimization, was used to generate relaxed structures for amorphous cellulose. Properties related to inter-molecular...
It has been well established that polyurethanes exhibit a two-phase micro-structure due to the thermodynamic incompatibility between the soft segments and hard segments. In this work, we reported the effect of fluorinated side chain attached on hard segment on the phase separation and surface topography of polyurethanes. Two sets of fluorinated polyurethanes, namely, poly(ether urethane)s and poly(carbonate...
Two new hydroxyl-containing di(meth)acrylate monomers were synthesized from the reaction of methyl α-chloromethylacrylate (MCMA) and of ethyl α-chloromethylacrylate (ECMA) with glycerol. The monomers were obtained as mixtures of two isomers in different ratios and in combination with the analogous trimethacrylate monomers. Each monomer was isolated by column chromatography. The photopolymerization...
Dynamics of the miscible blend of poly(vinyl methyl ether) and poly(4-vinylphenol) [PVME/PVPh] have been studied using broadband dielectric relaxation spectroscopy (DRS). The results are compared with those reported for PVME/polystyrene [PS] and PVME/poly(2-chlorostyrene) [P2CS] blends to examine the effect of intermolecular hydrogen bonding. These blends have similar chemical structures, with the...
Polyamide 66 (PA66) has been complexed with the Lewis acid GaCl 3 for the purpose of disrupting the interchain hydrogen bonded network. FTIR and 13 C-NMR observations indicate that Ga metal cations form a 1:1 complex with the carbonyl oxygens of the PA66 amide groups. PA66-GaCl 3 films are amorphous and rubbery with a single relaxation, attributable to the glass transition...
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to quantitatively correlate to the surface chemical composition determined from XPS in poly(styrene-co-4-vinyl phenol) (STVPh)/poly(styrene-co-4-vinyl pyridine) (STVPy) blends or complexes when the hydroxyl contents in STVPh copolymers were gradually increased. It was found that different mixing thermodynamics such as immiscibility,...
Phase structures of blends of poly(N-vinylpyrrolidone) (PVP) with SO 3 H terminated polystyrene (PSS) were investigated. The PVP-PSS blends were macroscopically homogeneous, although the blends of PVP with polystyrene (PS) showed macroscopic phase separation. The PVP-PSS blends, however, showed two glass transitions indicating existence of two phases. Small-angle X-ray scattering measurements...
We have investigated the thermal and spectroscopic properties of blends of poly(vinylpyrrolidone) (PVP) with zinc perchlorate. Analyses by differential scanning calorimetry indicates that blending with zinc perchlorate increases the values of T g of PVP. We calculated the interaction strength of the zinc salt/PVP blends based on an extended configuration entropy model. The presence of ion–dipole...
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