Component Homopolymers Research Articles

Quantitative Studies of Block Copolymers and Their Containing Homopolymer Components by Diffusion Ordered Spectroscopy

AbstractSeveral polystyrene‐b‐poly(methyl methacrylate) (PS‐b‐PMMA) and polyisoprene‐b‐PMMA (PI‐b‐PMMA) block copolymers are studied with high‐resolution diffusion ordered spectroscopy (DOSY) in order to quantify the amounts and molar masses of the copolymers and the containing homopolymers. These studies are particularly challenging because these homopolymers and one block of the copolymers consist of the same monomer type with different molar masses and compositions and cause a total overlap of these polymer components in the NMR spectra. However, DOSY can be proven as a powerful tool for separation and quantification of these moieties. Whereas exponential fittings only deliver averaged diffusion data, biexponential fittings of the individual magnetization curves can separate the overlapping polymer parts. This DOSY approach can be successfully tested for different blends of PS as well as PS and PS‐b‐PMMA of different molar masses and weighed compositions. The DOSY separation is also compared to size exclusion chromatography (SEC). In the case of the PS‐b‐PMMA and PI‐b‐PMMA block copolymers, DOSY identifies the contaminations with homopolymers, quantifies their individual amounts as well as determines the molar masses of both the copolymers and homopolymers. Two mathematical evaluations are used for quantifying these homopolymers with DOSY. These results are compared with the online coupling of SEC and NMR.

A study to identify the contribution of Soluplus® component homopolymers to the solubilization of nifedipine and sulfamethoxazole using the melting point depression method

PurposeExploit the Flory-Huggins Theory and its interaction parameter to measure the contribution of each of the homopolymers of the graft copolymer Soluplus® to the solubilization of sulfamethoxazole (SMX) and nifedipine (NIF). MethodsThe melting point depression for each crystalline drug in the presence of Soluplus® and each of its component homopolymers, namely poly(N-vinyl caprolactam) (PVCL), poly(vinylacetate) (PVAc), and poly(ethyleneglycol) (PEG), was measured at various drug levels using differential scanning calorimetry. Glass transition temperatures were calculated across the entire range for drug-polymer mixtures for comparison to the Gordon-Taylor prediction. The intersection of the melting point depression curve with the mixture glass transition curve provides an estimate of the solubility of the drug in the polymer. The solubility of these crystalline drugs in each homopolymer was calculated and a solubility in Soluplus® was estimated based on the homopolymer contributions. ResultsPEG 6000 exhibited a negative interaction parameter with SMX and NIF, indicating a relatively strong drug-polymer interaction. For PVAc, a small positive interaction parameter indicated a relatively weak drug-polymer interaction. The approach was not suitable for assessing the drug-PVCL interaction. However, other approaches could be taken to estimate the solubility of the drug in a polymer, including extrapolating the enthalpy of melting as a function of the volume fraction of the polymer to zero enthalpy to determine the maximum concentration miscible with the polymer and equating a parameter across the ideal solubility equation and the Flory-Huggins equation. ConclusionThe Flory-Huggins Theory allowed identification of the contribution of two of the homopolymers to the solubilization of NIF and SMX by Soluplus®, namely PEG and PVAc. PVAc and PVCL each demonstrated a weak interaction with each drug. However, PEG 6000 would substantially contribute to the drug solubilization due to its marked affinity for each drug.

Ultrathin film crystallization of poly(ε-caprolactone) in blends containing styrene-isoprene block copolymers: The nano-rose morphology

We report the discovery of a new nanostructured morphology in ultrathin blend films of semi-crystalline poly(ε-caprolactone) (PCL) and various styrene-isoprene block copolymers. The nano-rose morphology is visualized by atomic force microscopy as a monolayer of approximately 500 nm diameter crystalline spirals. Our finding that the nano-rose morphology occurs in a narrow film thickness window commensurate with the crystalline lamellar thickness suggests that this distinctive morphology results from redirection of growing PCL crystalline lamellae due to confinement effects during film casting. The nano-rose morphology was located in blends with several block copolymers of various architecture but was absent in blends with the individual homopolymer components. PCL molecular weight did not affect nano-rose size or film thickness window. However, solvent choice was an important factor, with nano-rose formation favored in non-polar and weakly polar solvents. This work supports theories that unbalanced surface stresses and impurity exclusion cause polymer crystals to grow unconventionally.

Investigation of the in vitro performance difference of drug-Soluplus® and drug-PEG 6000 dispersions when prepared using spray drying or lyophilization

Purpose: To evaluate the physicochemical and in vitro characteristics of solid dispersions using BCS II model drugs with Soluplus® and one of its component homopolymers, PEG 6000. Methods: Nifedipine (NIF) and sulfamethoxazole (SMX) of 99.3% and 99.5% purity, respectively, were selected as BCS II model drugs, such that an improved dissolution rate and concentration in the gastrointestinal tract should increase oral bioavailability. Soluplus® is an amorphous, tri-block, graft co-polymer with polyvinyl caprolactam, polyvinyl acetate, and polyethylene glycol (PCL:PVAc:PEG6000) in the ratio 57:30:13. PEG 6000 (BASF) is a waxy material with melting point of about 60°C. Solid dispersions were prepared using lyophilization or spray drying techniques. Dissolution study, crystallinity content, and analysis for new chemical bond formation have been used to evaluate the dispersed materials. Results: Although each polymer improved the drug dissolution rate, dissolution from Soluplus® was slower. Enhanced dissolution rates were observed with NIF solid dispersions, but the dissolution profiles were quite different due to the selected technique, polymer, and dissolution medium. For SMX, there was similarity across the dissolution profiles despite the medium, polymer, or applied technique. Each polymer was able to maintain an elevated drug concentration over the three hour duration of the dissolution profile, i.e., supersaturation was supported by the polymer. DSC thermograms revealed no melting endotherm, suggesting that the drug is amorphous or molecularly dispersed. Conclusion: NIF and SMX solid dispersions were successfully prepared by spray drying and lyophilization using Soluplus® or PEG 6000. Each polymer enhanced the drug dissolution rate; NIF dissolution rate was improved to a greater extent. Dispersions with PEG 6000 had a faster dissolution rate due to its hydrophilic nature. DSC analysis showed that no crystalline material exists in the dispersions.

A dual-stimuli-responsive polymer into phospholipid membranes

In this study, we investigate the thermotropic effects of diblock copolymer poly(N-isopropylacrylamide)-block-poly(acrylic acid) (PNIPAM-b-PAA) on fully hydrated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers and its ability to alter the membranes’ organization, fluidity and phase behavior. The composition of the diblock copolymer and the nature of dispersion medium (pH and ionic strength) were also examined. For these purposes, pure DPPC lipid and polymer–lipid mixed systems, hydrated in three different dispersion media (i.e., HPLC-grade water, phosphate buffer saline and hydrochloric acid solution of pH 4.5), were investigated by differential scanning calorimetry. Two compositions of PNIPAM-b-PAA with different molar ratio of the polymeric blocks were used. PNIPAM-b-PAA presents great scientific interest due to the combination of the special characteristics of its homopolymer components; it is dual responsive both in temperature and in pH changes. The incorporation of the PNIPAM-b-PAA into the DPPC bilayers causes particularly significant perturbations in their thermotropic behavior, slightly different in each dispersion medium. The results indicated the ordering of the polymer guest near the polar head group surface probably by its PAA block and, on the other hand, the penetration of the PNIPAM block into the hydrophobic bilayer core, causing membrane disruption in a temperature-depended manner. We can conclude that the lipid–polymer interactions seem to be affected by the pH and the ionic strength of the hydration medium, as well as the polymer content incorporated in the DPPC bilayer. These studies could be a roadmap in order to rationally design and develop chimeric liposomes.

Preparative solution crystallization fractionation: a simple and rapid fractionation method for the chemical composition separation of complex ethylene-propylene copolymers

The molecular structure elucidation of complex ethylene-propylene copolymers (EPCs) has benefited tremendously from the ability to combine preparative temperature rising elution fractionation (prep TREF) with various conventional analytical techniques. Recently reported, prep TREF-high-temperature solvent gradient interaction chromatography (HT-SGIC) (Cheruthazhekatt et. al, Macromolecules 45:2025-2034, 2012) is one of the most effective and highly useful coupled methods that allow for the exact measurement of the chemical composition distribution (CCD) present in various components of EPCs. The major drawback of prep TREF involving slow crystallization and elution steps is the long time per experiment. Here, we present a new and by far the simplest and fastest preparative fractionation method for complex polyolefins-preparative solution crystallization fractionation (prep SCF). The scope of the present study was to achieve a fast fractionation of complex bulk samples into an amorphous, semicrystalline and highly crystalline fraction, in sufficient amounts for the subsequent detailed compositional analysis. The effects of two different solvents, xylene and trichlorobenzene (TCB), and their influence on the solution crystallization of chemically different components of EPC were systematically investigated by combining prep SCF with crystallization analysis fractionation (CRYSTAF), FTIR, differential scanning calorimetry (DSC) and HT-SGIC analyses. Significant differences in the chemical composition of similar SCF fractions obtained from xylene and TCB were observed indicating the strong influence of the solvent on solution crystallization. Prep SCF-HT-SGIC results showed that, under similar experimental conditions, TCB as the fractionation solvent provides superior separation of complex semicrystalline ethylene-propylene (EP) components. Very interestingly, for the first time, separation of soluble fractions (30°C) of iPP, EPC and PE homopolymer components in complex EPC was achieved by prep SCF in TCB. On the other hand, SCF fractionation in xylene provides a soluble fraction that is perfectly amorphous as has been shown by DSC and CRYSTAF. Based on these results, the present SCF approach and an updated method of the combination of prep SCF-HT-SGIC hold significant promise for the fractionation and characterization of similar complex EPCs in a simple way within a short analysis time, by using significantly smaller amounts of solvent compared to the previously reported, rather time-consuming, prep TREF-HT-SGIC combination. No similarly selective solution crystallization fractionations in preparative scale have been reported before.

Direct Transformation of Living Anionic Polymerization into RAFT-Based Polymerization

A method of direct switching from anionic polymerization into RAFT-based polymerization was developed. The transformation involved in situ addition of living carbanionic species, end-capped with DPE, toward CS2 and subsequent reaction with alkyl bromides, resulting in macro-RAFT agents (macro-CTAs). The macro-CTAs were used to mediate RAFT polymerization of (functional) vinyl monomers. These processes were performed in a continuous way without isolation of the intermediate. Diblock or ABA-type triblock copolymers, composed of polydiene segment and functional acrylate (2-hydroxyethyl acrylate, HEA) or acrylamide (N-isopropylacrylamide, NIPAM), were synthesized by RAFT polymerization mediated by PI macro-CTAs. The successful preparation of block copolymers was demonstrated by the self-assembly of amphiphilic diblock copolymer PI75-b-PNIPAM199 in water (selective solvent for PNIPAM) or heptane (selective solvent for PI). The obtained block copolymers are cleavable into homopolymer components due to the prese...

Fullerene Nanoparticles as Molecular Surfactant for Dewetting of Phase-Separating Polymer Blend Films

We investigate the effects of fullerene nanoparticles (f-NP) on the dewetting morphology in the immiscible temperature regime of blend films of polystyrene (PS) and polybutadiene (PB) on silicon substrate. As in our former work in the miscible temperature regime of this blend film, competitive partitioning of the f-NPs to the polymer–polymer and the substrate interfaces in blend films requires a larger concentration of f-NPs (∼10 mass %) to suppress film dewetting than in homopolymer components (∼2 mass %). In contrast, however, phase-separated blend films rapidly dewet into hemispherical droplets due to finite interfacial tension of internal blend components unlike irregular shape droplets obtained in miscible blend films. The effect of the f-NPs (1 mass % to 5 mass % f-NP) is to simultaneously reduce the size and contact angle of the dewet droplets, but the hemispherical shape of droplets is maintained, suggesting the f-NPs act to (a) only reduce the phase-separated blend interfacial tension but not fully compatibilize it into single phase and (b) reduce the blend substrate interfacial tension progressively. Selective solvent etching of the PS blend component reveals a spherical PS core enclosed within a circular PB shell at all f-NP concentrations. Confocal fluorescence microscopy reveals that the f-NPs are distributed in both phases consistent with the hemispherical shape and calculations that predict only a weak reduction of interfacial tension. The dewet blend droplet contact angle (likewise polymer–substrate interfacial tension) measured by atomic force microscopy shows a bimodal behavior, reducing rapidly (by 40%) at low (0.1 mass %) f-NP levels and significantly slowing down at higher f-NP concentrations. Molecular surfactant like behavior of the f-NPs in the blend films then provides an effective means of tuning dewetting blend film morphology dimensions without compromising phase behavior for potential applications in nanotechnology and nanomedicine.

Quantitative analysis of interfacial tension effect on the impact strength of organic flame retardants and acrylonitrile‐butadiene‐styrene blends

AbstractFor a polymeric blend containing powder additive, quantitative analysis of its mechanical performances with interfacial tension methodology is generally a difficult work because it needs at least two groups of consistent and comparable surface tension data, either for the polymer matrix or for the powder additive, to calculate their interfacial tension. In this article, to quantitatively analyze the effect of interfacial tension on the impact strength of acrylonitrile‐butadiene‐styrene/flame retardants (ABS/FR) blends, the surface tension components (STC) of three organic flame retardant powders, FR‐245 (2,4,6‐tris(2,4,6‐tribromophenoxy)‐1,3,5 triazine), decabromodiphenyl oxide, and charringefoaming agent were measured through the combination of contact angle (CA) and inverse gas chromatography technique. The relationship of the STC measured from CA between ABS resin and its homopolymer components (polyacrylonitrile, polybutadiene, and polystyrene) was also researched. Then, the interfacial tension between the three FR and ABS was calculated. It was found that the impact strength of the ABS/FR blends decreased almost linearly with the increase of the interfacial tension, and the linear correlation degree reached a very high value, 0.9969. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Relationship between Hansen Solubility Parameters of ABS and its Homopolymer Components of PAN, PB, and PS

ABS, an important terpolymer produced from acrylonitrile, butadiene, and styrene, is widely used in the form of ABS alloys. Because the microstructure of ABS and its alloys shows a multiphase, researching the miscibility is of significant concern for ABS applications. In order to completely understand the special solubility properties of ABS resin, the relationship between Hansen solubility parameters (HSP) of ABS and its homopolymer components (polystyrene, polyacrylonitrile, and polybutadiene) were researched by the Hansen method in this paper. It was found that the dipolar component and hydrogen-bonding component of polyacrylonitrile were the strongest, and the dipolar component and hydrogen-bonding component of polybutadiene were the weakest. An interesting phenomenon was observed, namely that the HSP of the copolymer of styrene-acrylonitrile (SAN) and ABS were very similar to the HSP of polystyrene. This means that the HSP of ABS, the typical terpolymer, were not the addition or average of the HSP of its three homopolymer components; instead they were decided by only one homopolymer component, the polystyrene segment.

Foaming strategies for bioabsorbable polymers in supercritical fluid mixtures. Part II. Foaming of poly(ɛ-caprolactone-co-lactide) in carbon dioxide and carbon dioxide + acetone fluid mixtures and formation of tubular foams via solution extrusion

This paper reports on the foaming of poly(ɛ-caprolactone-co-lactide) in carbon dioxide and carbon dioxide + acetone mixtures. Experiments were carried out in specially designed molds with porous metal surfaces and fluid circulation features to generate foams with uniform dimensions at 60, 70 and 80 °C at pressures in the range 7–28 MPa. Depending upon the conditions, foams with pores in the range from 5 to 200 μm were generated. Adding acetone to carbon dioxide improved the uniformity of the pores compared to foams formed by carbon dioxide alone. In addition, a unique high-pressure solution extrusion system was designed and used to form porous tubular constructs by piston-extrusion of a solution from a high-pressure dissolution chamber through an annular die into a second chamber maintained at controlled pressure/temperature and fluid conditions. Long uniform porous tubular constructs with 6 mm ID and 1 mm wall thickness were generated with glassy polymers like poly(methyl methacrylate) by extruding solutions composed of 50 wt% polymer + 50 wt% acetone, or 25 wt% polymer + 10% acetone + 65% carbon dioxide at 70 °C and 28 MPa. Pores were in the 50 μm range. The feasibility of forming similar tubular constructs were demonstrated with poly(ɛ-caprolactone-co-lactide) as well. Tubular foams of the copolymer with interconnected pores with pore sizes in the 50 μm range were generated by extrusion of the copolymer solution composed of 25 wt% polymer + 10 wt% acetone + 65 wt% carbon dioxide at 70 °C and 28 MPa. Reducing the acetone content in the solution led to a reduction of pore sizes. Comparisons with the foaming behavior of the homopolymer poly(ɛ-caprolactone) that were carried out in the molds with porous metal plates show that the foaming behavior of the copolymer is more akin to the foaming behavior of the caprolactone homopolymer component.

Characterization and thermal stability of cellulose‐graft‐polyacryloniytrile prepared by using KMnO4/citric acid redox system

AbstractAn effective condition of graft polymerization of acrylonitrile onto cellulose fiber in large volume of KMnO4/citric acid aqueous solution was examined and the produced grafted copolymers were characterized by using SEM, NMR, FTIR, XRD, TGA, and DSC in comparison with component homopolymers. Graft yield, GY, obtained by simple weighting method was close to the value obtained by NMR analysis. Significant change of chemical structure in cellulose fiber, other than graft reaction, was not detected by NMR and FTIR measurements, whereas a decrease in the degree of crystallinity by the reaction was detected by XRD measurement. It was pointed out that thermograms for grafted samples resembles with that of cellulose at T < 370°C and become similar with that for polyacrylonitrile at T > 370°C and the mass of residue at 550°C is proportional to the content of polyacrylonitrile (GY) only. It is concluded that thermal decomposition of both polymers occurs almost independently in grafted polymers and thermal stability of cellulose fiber is not improved. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Hydrolytic Degradation Behavior of a Renewable Thermoplastic Elastomer

The hydrolytic degradation of polylactide-polymenthide-polylactide triblock copolymers (37 degrees C, pH 7.4) is compared to that of the component homopolymers. In addition to mass loss and water uptake measurements, size exclusion chromatography (SEC), 1H NMR spectroscopy, differential scanning calorimetry (DSC), and mechanical testing were used to monitor property changes during degradation. The rate of copolymer degradation was significantly influenced by the molecular weight of the polylactide end blocks. Mass loss of the polylactide homopolymer and the copolymer samples was observed once a decrease in the total molecular weight of the samples of 20% occurred. 1H NMR spectroscopy and DSC analysis of the copolymers during degradation revealed that the released oligomers contained mostly polylactide. After initial water uptake in which the mechanical properties were compromised to an extent, the Young's modulus and elongation at break of the biorenewable copolymers remained relatively unperturbed for up to 16 weeks, with significant retention of thermoplastic elastomeric properties for up to 21 weeks.

Collagen and component polypeptides: Low frequency and amide vibrations

Collagen is a fibrous protein, which exists widely in the human body. The biomechanical properties of collagen depend on its triple helix structure and the corresponding low frequency vibrations. We use first-principles, density functional theory methods and analytical force fields to investigate the molecular vibrations of a model collagen compound, the results being validated by comparison with published, inelastic neutron scattering data. The results from these atomistic simulations are used at higher frequency to study the Amide I and V vibrations and therefore the vibrational signature of secondary and tertiary structure formation. In addition to collagen, its component homopolymers, poly-glycine and poly-proline are also studied. The Amide V vibration of glycine is strongly modified in going from the single helix of poly-glycine II to the triple helix of collagen. The collagen models are hydrated and this work allows us to discuss the relative merits of density functional theory and force field methods when tackling complex, partially crystalline systems.

Two Calorimetric Glass Transitions in Miscible Blends Containing Poly(ethylene oxide)

Miscible blends containing poly(ethylene oxide) (PEO) have been examined over the entire composition range using differential scanning calorimetry to explore further the reported presence of two glass transitions. Three systems, poly(ethylene oxide)−dimethyl ether (PEO−DME)/poly(methyl methacrylate) (PMMA), PEO/poly(lactide) (PLA), and PEO/poly(vinyl acetate) (PVAc), were chosen in order to study the effects of end-group chemistry, annealing time, and crystallinity on the calorimetric behavior of the blends. The molecular weight of PEO was kept low to minimize the interference due to crystallization. Two distinct glass transitions were observed in the mid-composition range for all three systems. The glass transition temperatures varied smoothly with blend composition between the glass transition temperatures of the two homopolymer components. It was found that the self-concentration model describes the composition dependence of these glass transitions well. Further investigation on selected PEO/PVAc blend...

Thermal and structural properties of blends of isotactic with atactic polystyrene

Blends of isotactic polystyrene (iPS) with non-crystallizable atactic polystyrene (aPS) were studied by differential scanning calorimetry and small angle X-ray scattering. The iPS/aPS blends, prepared by solution casting, were found to be miscible in the melt over the entire composition range. Both quenched amorphous and semicrystalline blends exhibit a single, composition-dependent glass transition temperature, depressed from that of either of the homopolymer components. Addition of aPS causes a decrease in crystallinity and in the rigid amorphous fraction, and suppression of the reorganization/recrystallization of iPS during thermal scanning: only one melting peak is observed for blends with larger aPS content. Formation and devitrification of the rigid amorphous fraction of iPS are also affected by aPS addition. The annealing peak, which is due to the relaxation of rigid amorphous fraction in parallel with melting of a tiny amount of crystals, is retarded with an increase of the composition of aPS, resulting in the slow devitrification of RAF in parallel with the melting of large amount of crystals. X-ray scattering shows that the long period in the iPS/aPS blends is greater than in the iPS homopolymer, and long period increases slightly as aPS content increases. Comparison of the volume fraction of phase 1 with the volume fraction crystallinity from DSC suggests that more and more amorphous phase is rejected outside the lamellar stacks as aPS content increases. The effect of aPS addition is to reduce the confinement of the amorphous phase chains. The cooperativity length, ξA, which is calculated from thermal analysis of the Tg region, increases with aPS addition. The interlamellar and extra-lamellar amorphous chains both contribute to the glass transition relaxation process.

Viscoelastic Properties of Polystyrene/Poly(2-vinylpyridne) Blends under Steady Shear Flow

Viscoelastic properties of immiscible polymer blends consisting of polystyrene and poly(2-vinylpyridine), both of which have almost the same viscoelastic properties are studied under steady shear flow in linear and non-linear regions for the viscoelastic properties of components. It was observed that shear rate dependence of shear viscosity of blend samples was the same as those of component homopolymers, implying that the excess shear stress is proportional to the shear rate in the linear and non-linear regions for component polymers. It was also observed that the excess first normal stress difference of the blends was also proportional to the shear rate. It is concluded that the scaling relations between the excess stresses and the shear rate observed for binary immiscible polymer blends consisting of components with similar Newtonian viscosities can be extended into the higher shear rate regions where the components show similar non-linear viscoelastic behaviors.

Spectroelectrochemical responses of thin-film conducting copolymers prepared electrochemically from mixtures of 3,4-ethylenedioxythiophene and 2,2′-bithiophene

Here we have studied the electrocopolymerisation of binary mixtures of functionalised thiophenes in varying compositions and determined independently for each copolymer the spectroelectrochemical responses and the composition of the material using X-ray photoelectron spectroscopy. We have observed strong correlations between the composition of the copolymer material and the composition of the binary solution from which the polymer was grown. In addition, we have shown that the spectroelectrochemical properties of the copolymers indicate the presence of random copolymer material where the lambda(Max) values of the neutral, undoped, polymer scales with composition but also suggest that there may be small amounts of block copolymer or phase-separated mixtures of the homopolymer components.

Redox-Sensitive Copolymer: A Single-Component pH Sensor

A novel redox-active copolymer has been developed, capable of sensing pH. The polymer incorporates the redox-active but pH-insensitive vinylferrocene moiety as the internal reference signal, alongside the redox-active and pH-sensitive vinylanthracene moiety. The anthracene moiety undergoes a Nernstian potential shift with pH. The various monomer and homopolymer components have been examined in turn and the electrochemical response of the polymer characterized. Furthermore, the pH response was found to be stable over a wide temperature range.

A Study on Thermal Stabilities of Poly(2-Methacrylamidopyridine)-Poly(Methyl Methacrylate) Blends

: Blends of poly(methyl methacrylate) (PMMA) and poly(2-methacrylamidopyridine) (PMAP) obtained from free radical polymerization were prepared by casting films from CHCl3 solution, followed by drying for a few days. The blends were characterized by differential scanning calorimetry and Fourier transform infra-red spectroscopy. Single glass transitions indicate that the blend components are miscible. Thermogravimetric analysis shows that thermal stabilities of the blends are low compared to those of the homopolymer components. At lower temperatures, the cyclic imidation reaction effectively degrades the PMAP component in the blends and this reaction occurs at lower temperatures than does that of PMAP homopolymer because of hydrogen bonding between imine structures in PMAP and the ester carbonyl in PMMA. Thermal degradation of the blends has been followed up also as the (infrared) IR changes in them. Thermal degradation of the blend (PMMA:PMAP = 50:50 by wt) has been produced both in monomer in lower percentage and 2-aminopyridine in higher percentage compared with those of the homopolymers.