Combinations of differential scanning calorimetry, Fourier transform infrared spectroscopy, optical microscopy, and small-angle X-ray scattering were used to investigate the influence of hydrogen bonding strength on the crystallization kinetics and morphologies in poly(ε-caprolactone) (PCL) blends with three different well-known hydrogen bond donating polymers, i.e., phenolic, poly(vinylphenol) (PVPh), and phenoxy. The strength of the intercomponent interactions in the blend system depends on the hydrogen bond donor group and occurs, based on the Painter−Coleman association model, in the order phenolic/PCL > PVPh/PCL > phenoxy/PCL. Significantly reduced overall crystallization kinetics and crystal growth rate in PCL crystalline phase were also in the order phenolic/PCL > PVPh/PCL > phenoxy/PCL, which is consistent with the relative strengths of their intermolecular hydrogen bonding. Our experimental findings show that the hydrogen bonding strength has a greater effect on the rate of crystallization than does the influence of the blend's glass transition temperature, which is related to its chain mobility. In addition, values of the surface free energy of chain folding and crystalline thickness in PCL blends depend strongly on the relative ratio of the interassociation equilibrium constant and the self-association equilibrium constant (K A/K B). In phenolic/PCL and PVPh/PCL blends, the values of the surface free energies of chain folding in the PCL crystalline phase are increased with an increase in the content of the hydrogen bond donating polymer since the K A is greater than the K B in these two blend systems. In contrast, in the phenoxy/PCL blend system, the smaller K A relative to the K B induces a smaller value for the surface free energy of chain folding than that of pure PCL. Various miscible crystalline/amorphous binary polymer blends exhibiting either strong hydrogen bonding or weak interactions are also reviewed.

In this study, we synthesized a series of the organic/inorganic hybrid star PCLs. These star PCLs can form inclusion complexes (ICs) with R-and γ-CD, but not with -CD. These CD ICs were characterized by XRD, solid-state 13 C CP/MAS NMR spectroscopy, 1 H NMR spectroscopy, FT-IR spectroscopy, DSC, and TGA. Our results suggest that the PCL chains of these star polymers lose their original crystalline properties and were included inside the channels provided by the CDs to form a columnar crystalline structures. The stoichiometries (PCL:CD) that we determined by 1 H NMR spectroscopy for all of the ICs with R-or γ-CD are higher than those of the corresponding CD/linear PCL ICs because of the steric hindrance around the bulky POSS core, which causes some of the -caprolactone units near the core to be free from complexation with the CDs. From these analyses, we proposed some possible structures for the CD/star PCL ICs.

The binary poly(acetoxystyrene)/poly(ethylene oxide) (PAS/PEO) blend system is fully miscible, as evidenced by a single glass transition temperature over a full range of compositions when analyzed by differential scanning calorimetry analysis, as a result of weak C-H‚‚‚O hydrogen-bonding interactions between the carbonyl groups of PAS and the methylene groups of PEO. One-and two-dimensional correlation spectroscopies provide positive evidence for this specific interaction between the two polymers. In addition, a negative polymer-polymer interaction parameter " 12" was calculated using the Flory-Huggins equation based on the melting depression of PEO. The presence of an amorphous PAS phase results in a reduction in the spherulite growth rate of PEO. Both the values of nucleation constant and the surface free energy of chain folding of PEO decrease with increasing PAS content, which indicates that the crystallization ability of PEO increases correspondingly.

We have investigated a new type of A-B/C blend, formed between poly(methyl methacrylateb-vinylpyrrolidone) and poly(vinylphenol) (PMMA-b-PVP/PVPh), that displays unusual phase behavior. In this blend, the PMMA (A) and PVP (B) blocks within the PMMA-b-PVP (A-B) copolymer are miscible; although PVPh (C) experiences attractive interactions (ξ e 0) through hydrogen bonding, with both the PVP and PMMA blocks, its interaction with the former block is significantly stronger than that with the latter (ξ BC . ξ AC ). We investigated the miscibility and phase behavior of this novel A-B/C blend through the use of FTIR spectroscopy, DSC, 13 C CP/MAS solid-state NMR spectroscopy, and TEM. The proton spin-lattice relaxation time in the rotating frame (T 1 F H ), which we determined using 13 C NMR spectroscopy, indicates that phase separation occurs for blends containing ca. 20-60 wt % PVPh. TEM images indicated clearly that the morphology of phase separation consists of a matrix of homogeneous mixed PVP/PVPh and micellar domains of excluded PMMA. This special phase behavior and miscibility is due mainly to the diversity of interactions that exist between the PMMA/PVPh and PVP/PVPh units.

We have investigated the miscibility and hydrogen-bonding behavior of ternary blends of phenoxy, phenolic, and poly(ε-caprolactone) (PCL) by using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. On the basis of DSC analyses, we observed a rare totally miscible ternary hydrogen-bonded polymer blend in the amorphous phase:  all compositions of this ternary blend display a single glass transition temperature. In addition, these single glass transition temperatures can be predicted well by extending the Kwei equation from the binary polymer blend to this ternary polymer blend. The infrared spectra indicate that the intermolecular hydrogen bonding of each pair of binary components still exists in the ternary polymer blend. We used the ternary totally miscible blend to determine the interassociation equilibrium constant between the hydroxyl groups of phenolic and the hydroxyl groups of phenoxy indirectly from the fraction of hydrogen-bonded carbonyl groups of PCL. Quantitative analyses suggest that interassociation between the hydroxyl groups of phenolic and the hydroxyl groups of phenoxy is more favorable than the hydroxyl−carbonyl interassociations of either phenolic/PCL or phenoxy/PCL and the hydroxyl−hydroxyl self-association of the pure phenolic and phenoxy homopolymers at room temperature.