Electropolymerization of layer‐by‐layer precursor polymer films

The layer‐by‐layer (LbL) self‐assembly has been used to fabricate polymer thin films on any solid substrates. The multilayer polymer thin films are constructed by alternating adsorption of anionic and cationic polymers. Polyelectrolyte multilayer ultrathin films containing anionic poly[2‐(thiophen‐3‐yl)ethyl methacrylate‐co‐methacrylic acid]; P(TEM‐co‐MA) and cationic poly[4‐(9H‐carbazol‐9‐yl)‐N‐butyl‐4‐vinyl pyridium bromide]; P4VPCBZ, were fabricated. The growth of multilayer ultrathin films was followed by UV–Vis absorption spectrophotometer and surface plasmon resonance spectroscopy (SPR). The deposition of P(TEM‐co‐MA)/P4VPCBZ as multilayer self‐assembled ultrathin films regularly grow which showed linear growth of absorbance and thickness with increasing the number of layer pair. Cross‐linking of the layers was verified by cyclic voltammetry (CV), UV–Vis spectrophotometry and electrochemical surface plasmon resonance (EC‐SPR) spectroscopy with good electro‐copolymerizability. This was verified by spectroelectrochemistry. The SPR angular‐reflectivity measurement resulted in shifts to a higher reflectivity according to the change in the dielectric constant of the electropolymerized film. Copyright © 2011 John Wiley & Sons, Ltd.     

Adsorptive Voltammetry of Polyelectrolyte Complex Between 11‐Ferrocenyltrimethylundecylammonium and Polyanions at Carbon Paste Electrode

For polyelectrolyte complex between cationic surfactant and polyanion, the adsorptive voltammetry at carbon paste electrode using an electroactive cationic surfactant was examined. The adsorption state of the cationic surfactant in the complexes at CPE was estimated from the half‐height width of the oxidation waves. The half‐height width for poly(styrene sulfonate) was independent of the molecular weight, and was same as that for poly(vinyl sulfate). The half‐height width for heparin was broad and different from that of the vinyl polyanions. According to the analysis by Frumkin isotherm, the interaction between cationic surfactants was attractive in heparin complex at CPE, however, in the vinyl polyanion complexes at CPE the interaction was non‐cooperative as that predicted with the Langmuir isotherm. In spite of the same adsorption state, the concentration dependency of the peak current for poly(styrene sulfonate) was quite different from that for poly(vinyl sulfate). The concentration dependence indicated the reactive property of each polyanion on the association with the cationic surfactant in aqueous solution.     

Amphiphilic conetworks. II. Novel two‐step synthesis of poly[2‐(dimethylamino)ethyl methacrylate]–polyisobutylene,poly(N‐isopropylacrylamide)–polyisobutylene,and poly(N,N‐dimethylacrylamide)–polyisobutylene hydrogels

Amphiphilic polymer conetworks consisting of hydrophilic poly[2‐(dimethylamino)ethyl methacrylate], poly(N‐isopropylacrylamide), or poly(N,N‐dimethylacrylamide) and hydrophobic polyisobutylene chains were synthesized with a novel two‐step procedure. In the first step, a methacrylate‐multifunctional polyisobutylene crosslinker was prepared by the cationic copolymerization of isobutylene with 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate. In the second step, the methacrylate‐multifunctional polyisobutylene crosslinker, with a number‐average molecular weight of 8200 and an average functionality of approximately 4 per chain, was copolymerized radically with 2‐(dimethylamino)ethyl methacrylate, N‐isopropylacrylamide, or N,N‐dimethylacrylamide into transparent amphiphilic conetworks containing 42–47 mol % hydrophilic monomer. The synthesized conetworks were characterized with solid‐state ¹³C NMR spectroscopy and differential scanning calorimetry. The amphiphilic nature of the conetworks was proved by swelling in both water and n‐heptane. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6378–6384, 2006     

Solvent Resistant Honeycomb Films from Photo‐Crosslinkable Polycinnamate

Microporous films consisting of two‐dimensionally ordered void structures ‐ so‐called honeycomb films ‐ were produced by evaporation of polymer solutions under high humidity. Two types of poly(vinyl cinnamate)s were used: A newly synthesized amphiphilic poly(vinyl cinnamate) and a mixture of a commercial poly(vinyl cinnamate) and an amphiphilic polyion complex. Photo‐crosslinking of the honeycomb structure could be achieved by UV irradiation while completely retaining the film morphology. The crosslinked films showed excellent stability against organic solvents.

     

Interaction of small amounts of bovine serum albumin with phospholipid monolayers investigated by surface pressure and atomic force microscopy

The influence of small amounts of bovine serum albumin (BSA) (nM concentration) on the lateral organization of phospholipid monolayers at the air-water interface and transferred onto solid substrates as one-layer Langmuir-Blodgett (LB) films was investigated. The kinetics of adsorption of BSA onto the phospholipid monolayers was monitored with surface pressure isotherms in a Langmuir trough, for the zwitterionic dipalmitoylphosphatidyl ethanolamine (N,N-dimethyl-PE) and the anionic dimyristoylphosphatidic acid (DMPA). A monolayer of N,N-dimethyl-PE or DMPA incorporating BSA was transferred onto a solid substrate using the Langmuir-Blodgett technique. Atomic force microscopy (AFM) images of one-layer LB films displayed protein-phospholipid domains, whose morphology was characterized using dynamic scaling theories to calculate roughness exponents. For DMPA-BSA films the surface is characteristic of self-affine fractals, which may be described with the Kardar-Parisi-Zhang (KPZ) equation. On the other hand, for N,N-dimethyl-PE-BSA films, the results indicate a relatively flat surface within the globule. The height profile and the number and size of globules varied with the type of phospholipid. The overall results, from kinetics of adsorption on Langmuir monolayers and surface morphology in LB films, could be interpreted in terms of the higher affinity of BSA to the anionic DMPA than to the zwitterionic N,N-dimethyl-PE. Furthermore, the effects from such small amounts of BSA in the monolayer point to a cooperative response of DMPA and N,N-dimethyl-PE monolayers to the protein.     

Synthesis of poly(vinyl ether)‐based,ABA triblock‐type thermoplastic elastomers with functionalized soft segments and their gas permeability

The ABA‐type triblock copolymers consisting of poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] as outer hard segments and poly(6‐acetoxyhexyl vinyl ether) [poly(AcHVE)], poly(6‐hydroxyhexyl vinyl ether) [poly(HHVE)], or poly(2‐(2‐methoxyethoxy)ethyl vinyl ether) [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxyl, and oxyethylene units in their soft segments, the block copolymers formed elastomeric films. The thermal and mechanical properties and morphology of the block copolymers showed that the two polymer segments of these triblock copolymers were segregated into microphase‐separated structure. Effect of the functional groups in the soft segments on gas permeability was investigated as one of the characteristics of the new functional thermoplastic elastomers composed solely of poly(vinyl ether) backbones. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1114–1124     

Synthesis and hydrogel formation of fluorine‐containing amphiphilic ABA triblock copolymers

Fluorine‐containing amphiphilic ABA triblock copolymers, poly(2‐hydroxyethyl vinyl ether)‐block‐poly[2‐(2,2,3,3,3‐pentafluoropropoxy)ethyl vinyl ether]‐block‐poly(2‐hydroxyethyl vinyl ether) [poly(HOVE‐b‐PFPOVE‐b‐HOVE)] (HFH), poly[2‐(2,2,3,3,3‐pentafluoropropoxy)ethyl vinyl ether]‐block‐poly(2‐hydroxyethyl vinyl ether)‐block‐poly[2‐(2,2,3,3,3‐pentafluoropropoxy)ethyl vinyl ether] [poly(PFPOVE‐b‐HOVE‐b‐PFPOVE)] (FHF), and poly(n‐butyl vinyl ether)‐block‐poly(2‐hydroxyethyl vinyl ether)‐block‐poly(n‐butyl vinyl ether) [poly(NBVE‐b‐HOVE‐b‐NBVE)] (LHL), were synthesized, and their behavior in water was investigated. The aforementioned polymers were prepared by sequential living cationic polymerization of 2‐acetoxyethyl vinyl ether (AcOVE) and PFPOVE or NBVE, followed by hydrolysis of acetyl groups in polyAcOVE. FHF and LHL formed a hydrogel in water, whereas HFH gave a homogeneous aqueous solution. In addition, the gel‐forming concentration of FHF was much lower than that of corresponding LHL. Surface‐tension measurements of the aqueous polymer solutions revealed that all the triblock copolymers synthesized formed micelles or aggregates above about 1.0 × 10^?4 mol/L. The surface tensions of HFH and FHF solutions above the critical micelle concentration were lower than those of LHL, indicating high surface activity of fluorine‐containing triblock copolymers. Small‐angle X‐ray scattering measurements revealed that HFH formed a core‐shell sperical micelle in 1 wt % aqueous solutions, whereas the other block copolymers caused more conplicated assembly in the solutions. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3751–3760, 2001     

Novel Amphiphilic Degradable Poly(ε‐caprolactone)‐graft‐poly(4‐vinyl pyridine), Poly(ε‐caprolactone)‐graft‐poly(dimethylaminoethyl methacrylate) and Water‐Soluble Derivatives

New amphiphilic graft copolymers that have a poly(ε‐caprolactone) (PCL) biodegradable hydrophobic backbone and poly(4‐vinylpyridine) (P4VP) or poly(2‐(N,N‐dimethylamino)ethyl methacrylate) (PDMAEMA) hydrophilic side chains have been prepared by anionic polymerization of the corresponding 4VP and DMAEMA monomers using a PCL‐based macropolycarbanion as initiator. The water solubility of these amphiphilic copolymers is improved by quaternization, which leads to fully water‐soluble cationic copolymers that give micellar aggregates in deionized water with diameters ranging from 65 to 125 nm. In addition, to improve the hydrophilicity of PCL‐g‐P4VP, grafting of poly(ethylene glycol) (PEG) segments has been carried out to give a water‐soluble double grafted PCL‐g‐(P4VP;PEG) terpolymer.

     

Spin Self‐Assembled Clay Nanocomposite Passivation Layers Made from a Photocrosslinkable Poly(vinyl alcohol) and Na+‐Montmorillonite Enhance the Environmental Stability of Organic Thin‐Film Transistors

We investigated the effects of the multilayer polymer‐clay nanohybrid passivation films on the stability of pentacene organic thin‐film transistors (OTFTs) exposed to air and UV irradiation. Well‐ordered multilayer films were deposited by the spin‐assisted layer‐by‐layer assembly method using photocrosslinkable poly(vinyl alcohol) with the N‐methyl‐4(4′‐formylstyryl)pyridinium methosulfate acetal group (SbQ‐PVA) and Na⁺‐montmorillonite in a water‐based solution process. When photocrosslinked, these SbQ‐PVA/clay multilayers were found to serve as excellent barriers to O₂ and UV‐light. Moreover, when used as passivation layers, they enhanced the stability of pentacene OTFT devices exposed to air and UV radiation.     

Structure in the condensed state and amphiphilic properties of novel copolymers having alkyl chains and phosphatidylcholine analogous groups

N‐Stearylacrylamide (SAAm), N‐oleylacrylamide (OAAm), and N‐laurylacrylamide (LAAm) were synthesized. They were characterized by ¹H‐NMR, ¹³C‐NMR, FT‐IR, melting point measurements, and elemental analysis. The copolymerizations of SAAm, OAAm, and LAAm with 2‐[(3‐(acrylamido)propyl)dimethylammonio]ethyl 2′‐isopropyl phosphate were carried out, and a series of amphiphilic poly(acrylamide)s (1a,b, 2, and 3a,b) were obtained. These copolymers showed polyelectrolyte behavior in their viscous properties in polar solvents. X‐ray diffraction analysis indicated that the copolymers 1a,b formed similar stacked bilayers with hydrophilic groups and hydrophobic parts. The polymorphic phase transition of these copolymers was also observed by DSC. In addition, the monolayers as well as LB films of these amphiphilic copolymers were prepared on the surface of water and their π–A isotherms were investigated at different temperatures. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1293–1302, 1999     

Gold‐Loaded Carbon Nanoparticles from Poly(vinyl alcohol)‐b‐poly(acrylonitrile) Non‐Shell‐Cross‐Linked Micelles

Herein we show that a new amphiphilic poly(vinyl alcohol)‐b‐poly(acrylonitrile) block copolymer dispersed in water can be easily loaded with gold nanoparticles by addition of chlorauric acid followed by reduction by sodium borohydride. After deposition of the so‐loaded micelles onto a silicon wafer, followed by an appropriate thermal treatment, the poly(acrylonitrile) core of the micelles is carbonized, while the poly(vinyl alcohol) shell is completely decomposed and volatilized, leading to gold encapsulated in carbon nanoparticles. The morphology of the micelles is maintained during thermal treatment without requiring shell‐cross‐linking of the micelles prior to pyrolysis.     

Manipulation of the adsorption of ionic surfactants onto hydrophilic silica using polyelectrolytes

This paper demonstrates the use of polyelectrolytes to modify and manipulate the adsorption of ionic surfactants onto the hydrophilic surface of silica. We have demonstrated that the cationic polyelectrolyte poly(dimethyl diallylammonium chloride), poly-dmdaac, modifies the adsorption of cationic and anionic surfactants to the hydrophilic surface of silica. A thin robust polymer layer is adsorbed from a dilute polymer/surfactant solution. The resulting surface layer is cationic and changes the relative affinity of the cationic surfactant hexadecyl trimethylammonium bromide, C16TAB, and the anionic surfactant sodium dodecyl sulfate, SDS, to adsorb. The adsorption of C16TAB is dramatically reduced. In contrast, strong adsorption of SDS was observed, in situations where SDS would normally have a low affinity for the surface of silica. We have further shown that subsequent adsorption of the anionic polyelectrolyte sodium poly(styrene sulfonate), Na-PSS, onto the poly-dmdaac coated surface results in a change back to an anionic surface and a further change in the relative affinities of the cationic and anionic surfactants for the surface. The relative amounts of C16TAB and SDS adsorption depend on the coverage of the polyelectrolyte, and these preliminary measurements show that this can be manipulated.     

Advantages of Surface‐Initiated ATRP (SI‐ATRP) for the Functionalization of Electrospun Materials

Surface‐initiated atom transfer radical polymerization (SI‐ATRP) is successfully applied to electrospun constructs of poly(L ‐lactide). ATRP macroinitiators are adsorbed through polyelectrolyte complexation following the introduction of negative charges on the polyester surface through its blending with a six‐armed carboxy‐terminated oligolactide. SI‐ATRP of glycerol monomethacrylate (GMMA) or 2‐(N,N‐diethylamino)ethyl methacrylate (DEAEMA) allows then to grow surface films with controllable thickness, and in this way also to control the wetting and interactions of the construct.     

Preparation and properties of nanosized fluorescent solid films based on a polyelectrolyte-surfactant complex with organic dyes

A procedure for preparing an organosoluble stoichiometric complex based on a cationic polyelectrolyte and an anionic surfactant is described. A method is proposed for forming monolayers at the water-air interface, along with conditions for preparing fluorescent nanosized solid films based on polyelectrolyte complex and organic dyes using the Langmuir-Blodgett (LB) method. The spectral and luminescent properties of the obtained films are investigated. It is established from the absorption and fluorescence spectra of LB films that electrostatic interaction between the molecules of polyelectrolyte complex and oxazine dyes results in dimer formation.     

Synthesis of amphiphilic copolymer brushes: Poly(ethylene oxide)‐graft‐polystyrene

A well‐defined amphiphilic copolymer brush with poly(ethylene oxide) as the main chain and polystyrene as the side chain was successfully prepared by a combination of anionic polymerization and atom transfer radical polymerization (ATRP). The glycidol was first protected by ethyl vinyl ether to form 2,3‐epoxypropyl‐1‐ethoxyethyl ether and then copolymerized with ethylene oxide by the initiation of a mixture of diphenylmethylpotassium and triethylene glycol to give the well‐defined polymer poly(ethylene oxide‐co‐2,3‐epoxypropyl‐1‐ethoxyethyl ether); the latter was hydrolyzed under acidic conditions, and then the recovered copolymer of ethylene oxide and glycidol {poly(ethylene oxide‐co‐glycidol) [poly(EO‐co‐Gly)]} with multiple pending hydroxymethyl groups was esterified with 2‐bromoisobutyryl bromide to produce the macro‐ATRP initiator [poly(EO‐co‐Gly)_(ATRP). The latter was used to initiate the polymerization of styrene to form the amphiphilic copolymer brushes. The object products and intermediates were characterized with ¹H NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, Fourier transform infrared, and size exclusion chromatography in detail. In all cases, the molecular weight distribution of the copolymer brushes was rather narrow (weight‐average molecular weight/number‐average molecular weight < 1.2), and the linear dependence of ln[M₀]/[M] (where [M₀] is the initial monomer concentration and [M] is the monomer concentration at a certain time) on time demonstrated that the styrene polymerization was well controlled. This method has universal significance for the preparation of copolymer brushes with hydrophilic poly(ethylene oxide) as the main chain. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4361–4371, 2006     

Block copolymer mediated synthesis of amphiphilic gold nanoparticles in water and an aqueous tetrahydrofuran medium: An approach for the preparation of polymer–gold nanocomposites

The synthesis of polymer‐matrix‐compatible amphiphilic gold (Au) nanoparticles with well‐defined triblock polymer poly[2‐(N,N‐dimethylamino)ethyl methacrylate]‐b‐poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate] and diblock polymers poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate], polystyrene‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate], and poly(t‐butyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate] in water and in aqueous tetrahydrofuran (tetrahydrofuran/H₂O = 20:1 v/v) at room temperature is reported. All these amphiphilic block copolymers were synthesized with atom transfer radical polymerization. The variations of the position of the plasmon resonance band and the core diameter of such block copolymer functionalized Au particles with the variation of the surface functionality, solvent, and molecular weight of the hydrophobic and hydrophilic parts of the block copolymers were systematically studied. Different types of polymer–Au nanocomposite films [poly(methyl methacrylate)–Au, poly(t‐butyl methacrylate)–Au, polystyrene–Au, poly(vinyl alcohol)–Au, and poly(vinyl pyrrolidone)–Au] were prepared through the blending of appropriate functionalized Au nanoparticles with the respective polymer matrices {e.g., blending poly[2‐(N,N‐dimethylamino)ethyl methacrylate]‐b‐poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate‐stabilized Au with the poly(methyl methacrylate)matrix only}. The compatibility of specific block copolymer modified Au nanoparticles with a specific homopolymer matrix was determined by a combination of ultraviolet–visible spectroscopy, transmission electron microscopy, and differential scanning calorimetry analyses. The facile formation of polymer–Au nanocomposites with a specific block copolymer stabilized Au particle was attributed to the good compatibility of block copolymer coated Au particles with a specific polymer matrix. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1841–1854, 2006     

Aggregation Behavior of Homo‐PS/PS‐b‐P2VP Blends at the Air/Water Interface

The mixed Langmuir monolayers and Langmuir–Blodgett (LB) films of homo‐polystyrene (h‐PS) and the diblock copolymer polystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) have been characterized by the Langmuir monolayer technique and tapping mode atomic force microscopy (AFM), respectively. When the content of h‐PS is below 80 wt.‐%, the mixed LB films of h‐PS/PS‐b‐P2VP mainly exhibit isolated circular nanoaggregates. With a further increase of the h‐PS content (80–95%), however, highly uniform and stable necklace‐network structures are observed in the mixed LB films.

     

Synthesis of biocompatible and biodegradable block copolymers of polyvinyl alcohol‐block‐poly(ε‐caprolactone) using metal‐free living cationic polymerization

Applications of metal‐free living cationic polymerization of vinyl ethers using HCl · Et₂O are reported. Product of poly(vinyl ether)s possessing functional end groups such as hydroxyethyl groups with predicted molecular weights was used as a macroinitiator in activated monomer cationic polymerization of ε‐caprolactone (CL) with HCl · Et₂O as a ring‐opening polymerization. This combination method is a metal‐free polymerization using HCl · Et₂O. The formation of poly(isobutyl vinyl ether)‐b‐poly(ε‐caprolactone) (PIBVE‐b‐PCL) and poly(tert‐butyl vinyl ether)‐b‐poly(ε‐caprolactone) (PTBVE‐b‐PCL) from two vinyl ethers and CL was successful. Therefore, we synthesized novel amphiphilic, biocompatible, and biodegradable block copolymers comprised polyvinyl alcohol and PCL, namely PVA‐b‐PCL by transformation of acid hydrolysis of tert‐butoxy moiety of PTBVE in PTBVE‐b‐PCL. The synthesized copolymers showed well‐defined structure and narrow molecular weight distribution. The structure of resulting block copolymers was confirmed by ¹H NMR, size exclusion chromatography, and differential scanning calorimetry. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5169–5179, 2009     

Tuning Surface Wettability of Poly(3‐sulfopropyl methacrylate) Brushes by Cationic Surfactant‐Driven Interactions

In this communication, polyanionic poly(potassium 3‐sulfopropyl methacrylate) (PSPM) brushes were switched from hydrophilic to hydrophobic by exchange of the counter cations. First, poly(potassium 3‐sulfopropyl methacrylate) brushes were grown by means of atom transfer radical polymerization (ATRP) from thiol monolayers of initiating ω‐mercaptoundecyl bromoisobutyrate and mixed monolayers of thiol initiator and 1‐undecanothiol (blank thiol) attached to gold surfaces. The kinetics of the polymerization reaction were followed by means of the quartz microbalance technique with dissipation (QCM‐D). The collapse of PSPM brushes in the presence of cationic surfactants like quaternary ammonium salts (tetraethylammonium bromide, hexadecyltrimethylammonium bromide) and imidazolium salts (1‐dodecyl‐3‐methylimidazolium bromide, 1H,1H,2H,2H‐perfluoro‐1‐decyl‐3‐methylimidazolium bromide) was shown by QCM‐D. Water contact angle measurements proved that the wettability of the surface could be tuned reversibly from hydrophilic values (<30 °) to hydrophobic ones (>85 °).

     

Thermoresponsive NIPAM block copolymers containing densely grafted poly(vinyl ether) brushes synthesized by a combination of living cationic polymerization and RAFT polymerization

Diblock copolymers consisting of a multibranched polymethacrylate segment with densely grafted poly[2‐(2‐methoxyethoxy)ethyl vinyl ether] pendants and a poly(N‐isopropylacrylamide) segment were synthesized by a combination of living cationic polymerization and RAFT polymerization. A macromonomer having both a poly[2‐(2‐methoxyethoxy)ethyl vinyl ether] backbone and a terminal methacryloyl group was synthesized by living cationic polymerization. The sequential RAFT copolymerizations of the macromonomer and N‐isopropylacrylamide in this order were performed in aqueous media employing 4‐cyanopentanoic acid dithiobenzoate as a chain transfer agent and 4,4′‐azobis(4‐cyanopentanoic acid) as an initiator. The obtained diblock copolymers possessed relatively narrow molecular weight distributions and controlled molecular weights. The thermoresponsive properties of these polymers were investigated. Upon heating, the aqueous solutions of the diblock copolymers exhibited two‐stage thermoresponsive properties denoted by the appearance of two cloud points, indicating that the densely grafted poly[2‐(2‐methoxyethoxy)ethyl vinyl ether] pendants and the poly(N‐isopropylacrylamide) segments independently responded to temperature. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013