Single- and double-C60-end-capped poly(ethylene oxide)s (PEOs) were prepared by reacting azido-terminated PEO with C60. The aggregation behavior of these polymers in THF and water was studied by gel permeation chromatography, static and dynamic laser light scattering, and transmission electron microscopy. The solvent polarity, the amount of C60, and the length of PEO segments significantly affect the conformation and the size distribution of aggregates or clusters. The aggregation number of single-C60-end-capped PEO exceeds 104, far larger than nonionic surfactants consisting of PEOs end-capped with paraffinic chains due to the stronger hydrophobic character of C60. Single-C60-end-capped PEO forms much larger aggregates than those of double-end-capped PEOs, possibly due to the relatively higher mobility of the former polymer. The PEO chain length of the double-C60-end-capped PEO controls the aggregate conformation and particle size distribution. It is believed that large aggregation complex comprises several smaller identical aggregates in THF solutions.

Poly(N-methyl-4-piperidinyl methacrylate) (PMPMA) was synthesized and characterized. PMPMA formed complexes with poly(p-vinylphenol) (PVPh) in ethanol over the entire feed composition range. The yields of complexes were in the range 29-76%, which were lower than those of poly(4-vinylpyridine) (P4VPy)/PVPh complexes obtained in ethanol. Complexation did not occur in N,Ndimethylformamide (DMF), but the DMF-cast blends were miscible. Fourier-transform infrared spectroscopic studies showed that the hydroxyl groups of PVPh interact with the carbonyl groups of PMPMA, and the intermolecular hydrogen-bonding interactions are weaker than the self-association of PVPh. X-ray photoelectron spectroscopic studies showed that the nitrogen atoms in the piperidine groups are not involved in intermolecular interactions with PVPh, likely a result of steric effects asserted by the N-methyl groups. Because of the inaccessibility of the piperidine nitrogen atoms, PMPMA interacts less intensely with PVPh than P4VPy does.

Complexation between C60-end-capped linear or four-arm poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) was studied. The introduction of hydrophobic [60]fullerene (C60) in PEO has a dramatic effect on the complex formation of the PEO/PAA system. Interestingly, the yields of C60-endcapped four-arm PEO/PAA complexes are lower than those of C60-end-capped linear PEO/PAA complexes. The result indicates a competition between the hydrophobic effect and the steric effect originated from C60. Similar to the PEO/PAA system, there are hydrogen-bonding interactions between the carboxylic acid groups of PAA and the ether oxygen in C60-end-capped PEOs.

The complexation behavior between poly(2‐hydroxypropyl methacrylate) (PHPMA) and three isomeric tertiary amide polymers, namely, poly(N‐methyl‐N‐vinylacetamide) (PMVAc), poly(N,N‐dimethylacrylamide) (PDMA), and poly(2‐ethyl‐2‐oxazoline) (PEOx), was studied. PHPMA forms interpolymer complexes with the three tertiary amide polymers at the entire feed composition range in methyl ethyl ketone and tetrahydrofuran solutions, indicating a strong intermolecular interaction between different polymer chains. However, complexation does not occur between PHPMA and the three tertiary amide polymers in N,N‐dimethylformamide solutions. Infrared spectroscopic studies show that the intermolecular hydrogen bonding association between the hydroxyl groups in PHPMA and the amide carbonyl groups in the tertiary amide polymers is stronger than the self‐association between the hydroxyl groups and the ester carbonyl groups in PHPMA. PHPMA has a stronger complexation ability with these tertiary amide polymers than poly(styrene‐co‐allyl alcohol) and poly(hydroxyether of bisphenol‐A) do. © 1994 John Wiley & Sons, Inc.

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Copolymers of 1,2,2,6,6‐pentamethyl‐4‐piperidinyl m‐isopropenyl‐α,α‐dimethylbenzyl carbamate (CB) with styrene (S) and with methyl methacrylate (MMA) were synthesized using AIBN as initiator. S–CB copolymers made from feed ranging from 0.45–0.94 mole fractions S and MMA‐CB copolymers made from feed of 0.34–0.88 mole fractions MMA were used to determine the monomer reactivity ratios r1 and r2. The structure of S–CB copolymers was inferred to be mainly of a random nature and in the MMA–CB copolymerization system there is a stronger tendency to form alternating copolymers. © 1993 John Wiley & Sons, Inc.

The miscibility behavior of poly(2,2-dichloroethyl methacrylate) (PDCEMA) and poly(2,2,2-trichloroethyl methacrylate) (PTCEMA) with various polymethacrylates was examined using differential scanning calorimetry. PDCEMA and PTCEMA are both miscible with poly(methy1 methacrylate), poly-(ethyl methacrylate), poly(n-propyl methacrylate) (PnPMA), poly(isopropy1 methacrylate) (PiPMA), poly-(tetrahydrofurfuryl methacrylate), and poly(cyclohexy1 methacrylate) but immiscible with poly(n-hexyl methacrylate). They differ in those cases involving poly(n-butyl methacrylate) (PnBMA), poly(n-amyl methacrylate) (PnAMA), and poly(isoamy1 methacrylate) (PiAMA). PDCEMA, but not PTCEMA, is miscible with PnBMA and PiAMA. PDCEMA has a limited miscibility with PnAMA, but PTCEMA is immiscible with PnAMA. Miscible blends of PDCEMA with PnPMA, PiPMA, PnBMA, and PiAMA showed lower critical solution temperature behavior. PDCEMA shows a wider range of miscibility with polymethacrylates than PTCEMA and other chlorine-containing polymethacrylates such as poly(chloromethy1 methacrylate), poly( 1-chloroethyl methacrylate), poly(2-chloroethyl methacrylate), and poly(3-chloropropyl methacrylate). The good miscibility of PDCEMA appears to be correlated to the acidic hydrogen in the pendant -CHCl:, group.

SYNOPSISThe miscibility behavior of various poly(p-methylstyrene-co-methacrylonitrile) (pMSMAN)/ poly(alky1 methacry1ate)s blends was studied using differential scanning calorimetry. pMSh4AN is miscible with poly(methy1 methacrylate), poly(ethy1 methacrylate), poly(n-propyl methacrylate), poly(isopropy1 methacrylate), and poly(n-butyl methacrylate) over certain copolymer composition ranges, but is immiscible with poly(isobuty1 methacrylate) and poly(n-amyl methacrylate). The width of the miscibility window decreases with increasing size of the pendant ester group of the poly(alky1 methacrylate), and is wider than that of the corresponding poly(pmethylstyrene-co-acrylonitrile) blend system. Various segmental interaction parameters are calculated using a binary interaction model. I NTRO DUCT10 NThe miscibility behavior of poly(alky1 methacry1ate)s with copolymers of acrylonitrile has been extensively studied. Poly(methy1 methacrylate) (PMMA), poly(ethy1 methacrylate) (PEMA) and poly(n-propyl methacrylate) (PnPMA) are miscible with poly(styrene-co-acrylonitrile) (SAN),14 poly(cymethylstyrene-co-acrylonitrile) (cYMSAN)~-~ and poly(p-methylstyrene-co-acrylonitrile) (pMSAN)' over certain copolymer composition ranges, showing "miscibility windows." The width of the miscibility window decreases with increasing size of pendant groups of the poly(alky1 methacrylate). Poly(isopropy1 methacrylate) (PiPMA) is immiscible with SAN2 and pMSAN! PiPMA is immiscible with an aMSAN sample containing 30 wt % of acryl~nitrile,~ but the miscibility of PiPMA with aMSAN of other compositions has not been reported. Poly(n-butyl methacrylate) (PnBMA) is immiscible with SAN,2 but it is miscible with aMSAN7 and pMSAN' over very narrow copolymer composition ranges.We have recently studied the miscibility behavior of poly(alky1 methacry1ate)s with poly(styrene-