Morphology,dynamic mechanical,and electrical properties of bio‐based poly(trimethylene terephthalate) blends,part 1: Poly(trimethylene terephthalate)/poly(ether esteramide)/polyethylene glycol 400 bis(2‐ethylhexanoate) blends

Bio‐based PTT and PTT blends with PEEA of two different ion contents (275 ppm Na and 3515 ppm Na) and PEG 400 bis (2‐ethylhexanoate) were prepared by melt processing. The blends were characterized by differential scanning calorimetry, dynamic mechanical analysis, transmission electron microscopy, and atomic force microscopy. Electro‐static performance was also investigated for those PTT blends since PEEA is known as an ion conductive polymer. Here we confirmed that PEG 400 bis (2‐ethylhexanoate) improves the static decay performance of PTT/PEEA blends. DMA strongly suggests that PEG 400 bis (2‐ethylhexanoate) and PEEA are miscible pairs, and PEG 400 bis (2‐ethylhexanoate) selectively goes into the PEEA phase rather than the PTT phase, which lowers the T_g of PEEA. Besides topographic analysis of morphology and phase separation, tunneling atomic force microscopy was also applied to see if we can observe the surface directly for the static dissipative material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Crystallization,morphology, and electrical properties of bio‐based poly(trimethylene terephthalate)/poly(ether esteramide)/ionomer blends

Bio‐based poly(trimethylene terephthalate) (PTT) and poly(ether esteramide) (PEEA) blends were prepared by melt processing with varying weight ratios (0–20 wt %) of ionomers such as lithium‐neutralized poly(ethylene‐co‐methacrylic acid) copolymer (EMAA‐Li) and sodium‐neutralized poly(ethylene‐co‐methacrylic acid) copolymer (EMAA‐Na). The blends were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), polarized light microscopy (PLM), and transmission electron microscopy (TEM). DSC and PLM results showed that EMAA‐Na increased the crystallization rate for PTT significantly, whereas EMAA‐Li did not enhance the crystallization rate at all. Specific interactions between PEEA and ionomers were confirmed by DSC and TEM. Electrostatic performance was also investigated for those PTT blends because PEEA is known as an ion‐conductive polymer. Here, we confirmed that both sodium and lithium ionomers work as a synergist to enhance the static decay performance of PTT/PEEA blends. Morphological study of these ternary blends systems was conducted by TEM. Dispersed ionomer domains were encapsulated by PEEA, which increases the interfacial surface area between PEEA and the PTT matrix. This encapsulation effect explains the unexpected synergy for the static dissipation performance on addition of ionomers to PTT/PEEA blends. This core–shell morphology can be predicted by calculating spreading coefficient for the ternary blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Spherulite morphology and crystallization behavior of poly(trimethylene terephthalate)/poly(ether imide) blends

The spherulite morphology and crystallization behavior of poly(trimethylene terephthalate) (PTT)/poly(ether imide) (PEI) blends were investigated with optical microscopy (OM), small-angle light scattering (SALS), and small-angle X-ray scattering (SAXS). Thermal analysis showed that PTT and PEI were miscible in the melt over the entire composition range. The addition of PEI depressed the overall crystallization rate of PTT and affected the texture of spherulites but did not alter the mechanism of crystal growth. When a 50/50 blend was melt-crystallized at 180 °C, the highly birefringent spherulite appeared at the early stage of crystallization (t < 20 min). After longer times, the spherulite of a second form was developed, which exhibited lower birefringence. The SALS results suggested that the observed birefringence change along the radial direction of the spherulite was mainly due to an increase in the orientation fluctuation of the growing crystals as the radius of spherulite increased. The lamellar morphological parameters were evaluated by a one-dimensional correlation function analysis. The amorphous layer thickness showed little dependence on the PEI concentration, indicating that the noncrystallizable PEI component resided primarily in the interfibrillar regions of the growing spherulites.     

Thermal properties and phase morphology of melt‐mixed poly(trimethylene terephthalate)/poly(hexamethylene isophthalamide) blends

This work examines the thermal properties and phase morphology of melt‐mixed poly(trimethylene terephthalate) (PTT)/poly(hexamethylene isophthalamide) (PA 6I) blends. Two temperatures, i.e., 250 and 260°C, are used to prepare the blends, respectively. Differential scanning calorimetry results indicate the immiscible feature of the blends. It is thus concluded that the ester‐amide interchange reaction hardly occurred in the PTT/PA 6I blends. Depending on the composition and mixing temperature, the crystallization ability of PTT in the blends is either enhanced or hindered. Basically, a lower PA 6I content shifts the PTT melt crystallization to a higher temperature, whereas a higher PA 6I content causes an opposing outcome. The original complex melting behavior of neat PTT becomes more regular after the incorporation of 60 wt % or 80 wt % of PA 6I. Thermogravimetry analyses (TGA) show that the thermal stability of the blends improves as the PA 6I content increases. The two‐phased morphology of the blends is examined by scanning electron microscopy (SEM). Polarized light microscopy (PLM) results reveal that the PTT spherulites become coarser with the inclusion of PA 6I; only smaller/dispersed crystallites are observed in the blend with 20 wt % of PTT. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanical properties and morphological changes of poly(lactic acid)/polycarbonate/poly(butylene adipate‐co‐terephthalate) blend through reactive processing

The mechanical properties and morphological changes of poly(lactic acid) (PLA), polycarbonate (PC), and poly(butylene adipate‐co‐terephthalate) (PBAT) polymer blends were investigated. Several types of blend samples were prepared by reactive processing (RP) with a twin‐screw extruder using dicumyl peroxide (DCP) as a radical initiator. Dynamic mechanical analyses (DMA) of binary polymer blends of PC/PBAT indicated that each component was miscible over a wide range of PC/PBAT mixing ratios. DMA of PLA/PBAT/PC ternary blends revealed that PBAT is miscible with PC even in the case of ternary blend system and the miscibility of PLA and PBAT can also be modified through RP. As a result, the tensile strain and impact strength of the ternary blends was increased considerably through RP, especially for PLA/PBAT/PC = 42/18/40 (wt/wt/wt) with DCP (0.3 phr). Scanning electron microscopy (SEM) analysis of the PLA/PBAT/PC blends revealed many small spherical island phases with a domain size of approximately 0.05–1 μm for RP, whereas it was approximately 10 μm without RP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thermal properties and non‐isothermal crystallization behavior of poly(trimethylene terephthalate)/poly(lactic acid) blends

Thermal properties and non‐isothermal melt‐crystallization behavior of poly(trimethylene terephthalate) (PTT)/poly(lactic acid) (PLA) blends were investigated using differential scanning calorimetry and thermogravimetric analysis. The blends exhibit single and composition‐dependent glass transition temperature, cold crystallization temperature (T_cc) and melt crystallization peak temperature (T_mc) over the entire composition range, implying miscibility between the PLA and PTT components. The T_cc values of PTT/PLA blends increase, while the T_mc values decrease with increasing PLA content, suggesting that the cold crystallization and melt crystallization of PTT are retarded by the addition of PLA. The modified Avrami model is satisfactory in describing the non‐isothermal melt crystallization of the blends, whereas the Ozawa method is not applicable to the blends. The estimated Avrami exponent of the PTT/PLA blends ranges from 3.25 to 4.11, implying that the non‐isothermal crystallization follows a spherulitic‐like crystal growth combined with a complicated growth form. The PTT/PLA blends generally exhibit inferior crystallization rate and superior activation energy compared to pure PTT at the same cooling rate. The greater the PLA content in the PTT/PLA blends, the lower the crystallization rate and the higher the activation energy. Moreover, the introduction of PTT into PLA leads to an increase in the thermal stability behavior of the resulting PTT/PLA blends. Copyright © 2011 Society of Chemical Industry     

Structure and mechanical properties of poly(trimethylene terephthalate)/poly(hydroxy ether of bisphenol A) blends

Compatible poly(trimethylene terephthalate) (PTT)/poly(hydroxy ether of bisphenol A) (Phenoxy) blends were obtained by direct injection molding throughout the composition range. Two amorphous phases with minor amounts of the other component were found in the blends. Reactions occurred in PTT‐rich blends. By comparing the miscibility level of these blends with that of other blends based on polyalkylene terephthalates, it is proposed that a miscibility limit delimited by a 3/1 methylene–carbonyl ratio in the polyalkylene terephthalate exits in these blends. The synergism in the Young's modulus of the blends is discussed as a consequence of the changes in the crystallinity of PTT, the specific volume and the orientation produced by blending. Ductility is approximately proportional to blend composition, indicating compatibility, and is attributed to the combined effects of a small particle size and a good adhesion level, the latter being a consequence of the partially miscible nature of the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3246–3254, 2006     

Solid state structure and mechanical properties of melt mixed poly(trimethylene terephthalate)/polycarbonate blends

Poly(trimethylene terephthalate) (PTT)/poly (carbonate of bisphenol A) (PC) blends were obtained in the melt state by direct injection molding and also by extrusion followed by injection molding. The blends rich in PTT were monophasic, while the blends rich in PC were biphasic with the two components of the blends present in both phases. Both the monophasic and biphasic blends were partially miscibilized, and also partially reacted, as observed by FTIR. The extent of the reaction was greater in previously mixed blends. The observed synergism in the modulus of elasticity was attributed to the increased orientation of the blend components upon blending. Although decreases in elongation at break were observed and attributed to degradation of PTT, the blends were clearly ductile and compatible. This was a consequence of either their monophasic structure, or of the presence of the two components in the two phases of the blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Miscible blends of poly(4‐vinyl phenol)/poly (trimethylene terephthalate)

A new miscible blend of all compositions comprising poly(4‐vinyl phenol) (PVPh) and poly(trimethylene terephthalate) (PTT) was discovered and reported. The blends exhibit a single composition‐dependent glass transition and homogeneous phase morphology, with no lower critical solution temperature (LCST) behavior upon heating to high temperatures. Interactions and spherulite growth kinetics in the blends were also investigated. The Flory–Huggins interaction parameter (χ₁₂) and interaction energy density (B) obtained from analysis of melting point depression are negative (χ₁₂ = ?0.74 and B = ?32.49 J cm^?3), proving that the PVPh/PTT blends are miscible over a wide temperature range from ambient up to high temperatures in the melt state. FTIR studies showed evidence of hydrogen‐bonding interactions between the two polymers. The miscibility of PVPh with PTT also resulted in a reduction in spherulite growth rate of PTT in the miscible blend. The Lauritzen–Hoffman model was used to analyze the spherulite growth kinetics, which showed a lower fold‐surface free energy (σ_e) of the blends than that of the neat PTT. The decrease in the fold‐surface free energy has been attributed to disruption of the PTT lamellae exerted by PVPh in an intimately interacted miscible state. Copyright © 2004 Society of Chemical Industry     

Stereocomplexed polylactides (Neo‐PLA) as high‐performance bio‐based polymers: their formation,properties, and application

Polymeric materials prepared from renewable natural resources are now being accepted as “bio‐based polymers”, because they are superior to the conventional petroleum‐based polymers in reducing the emission of carbon dioxide. Among them, poly(L ‐lactide) (PLLA) prepared by fermentation and polymerization is paid an immediate attention. Although PLLA exhibits a broad range of physico‐chemical properties, its thermal and mechanical properties are somewhat poorer for use as ordinary structural materials. For improving these inferior properties, a stereocomplex form consisting of PLLA and its enantiomer poly(D ‐lactide) (PDLA) has high potential because of showing high melting nature (230 °C). It can be formed by simple polymer blend of PLLA and PDLA or more easily with stereoblock polylactides (sb‐PLA) which are PLLA/PDLA block copolymers. These novel PLA polymers, named “Neo‐PLA”, can provide a wide range of properties that have never be attained with single PLLA. Neo‐PLA retains sustainability or bio‐based nature, because both monomers L ‐ and D ‐lactic acids are manufactured from starch by fermentation. Copyright © 2006 Society of Chemical Industry     

Poly(ether ether ketone)/poly(aryl ether sulfone) blends: Relationships between morphology and mechanical properties

Mechanical properties such as the tensile modulus, yield (break) strength, and elongation to break (or yield) are measured for multiphase poly(ether ether ketone) (PEEK)/poly(aryl ether sulfone) (PES) blends. Specimens with three different levels of thermal histories (quenched, as‐molded, and annealed) are prepared in order to study their effects on the mechanical properties of PEEK/PES blends. Synergistic behavior is observed in the tensile modulus and tensile strength of the blends in almost the whole range of compositions. The ductility of quenched blends measured as the elongation to break (yield) shows an unexpected synergistic behavior in the blend containing 90 wt % PEEK, although a negative deviation from additive behavior is observed in the rest of the compositions. A ductile–brittle transition is observed between 50 and 75 wt % PEEK in the blend. The ductile–brittle transition in as‐molded blends shifts to 75–90 wt % PEEK. Annealed blends show predominantly brittle behavior in the whole composition range. The experimental data are further correlated with the theoretically predicted results based on various composite models. Although the prediction based on these equations fails to fit the experimental data in the whole composition range, the simplex equations that are normally used for blends showing synergistic behavior produced a reasonable fit to the experimental data. The mechanical properties obtained for different blend compositions are further correlated with their morphology as observed by scanning electron microscopy. Morphological observation shows a two‐phase morphology in PES‐rich blends, which is an interlocked morphology in which the disperse phase is not clearly visible in PEEK‐rich blends, and a cocontinuous type of morphology for a 50/50 composition. Considerable permanent deformation of both the disperse and matrix phase, especially in the case of quenched tensile specimens, demonstrates the remarkable adhesion present between the two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2887–2905, 2003     

Lamellar morphology of poly(trimethylene terephthalate)/poly(ether imide) blends studied via small‐angle X‐ray scattering

The lamellar morphology of a melt‐miscible blend consisting of poly(trimethylene terephthalate) (PTT) and poly(ether imide) (PEI) prepared by solution precipitation has been investigated by means of optical polarized microscopy (POM) and small angle X‐ray scattering (SAXS). From the observation under POM, it was suggested that PEI was predominantly segregated into the interlamellar and/or interfibrillar regions upon PTT crystallization since the PTT spherulitic morphologies of blends were volume‐filling. From results of SAXS data analysis, a larger amorphous layer thickness was identified in the blends, showing that some PEI was incorporated inside the interlamellar regions after crystallization. Despite the swelling of the amorphous layer, the amorphous layer thickness was relatively independent of the blend composition. It was concluded that amorphous PEI was located in the interlamellar regions of PTT as the weight fraction of PEI (w_PEI) [≤] 0.1, while amorphous PEI was predominantly segregated into the interfibrillar regions of PTT as w_PEI > 0.1, and the extent of interfibrillar segregation increased with increasing w_PEI. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Effects of mixing time on phase structure and mechanical properties of poly(ethylene terephthalate)/ polycarbonate blends

The effects of interchange reactions on the solid‐state structure and mechanical properties of a 70/30 poly(ethylene terephthalate) (PET)/bisphenol A polycarbonate (PC) blend were studied. Increasing reaction levels were obtained by means of lower screw speeds in the extruder. The progressive production of copolymers with the reaction time increased the amount of each component in the other phase. The concomitant degradation of PET led to a maximum in ductility and tensile and impact strengths whereas the modulus of elasticity and the yield stress were held constant. The maximum in properties took place at a reaction time close to 2.6 min; at longer reaction times the negative effect of degradation began to overcome the positive effect of the interchange reactions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 121–127, 2001     

Morphology and electrical properties of carbon black/poly(ethylene terephthalate)/polypropylene composite

This work attempts to develop a carbon black (CB) filled conductive polymer composite based on poly(ethylene terephthalate) (PET) and polypropylene (PP). The process follows by localizing the CB particles in the minor phase (PET), and then the conductive masterbatch was elongated to form conductive microfibrils in PP matrix during melt extrusion process. After compression molding, a fine conductive three‐dimensional microfibrillar network is constructed. For comparison purpose, CB, PET, and PP are mixed using different pattern. The morphology and the volume resistivity of the obtained composites are evaluated. Electrical conductivity investigation shows that the percolation threshold and resistivity values are dependent on the CB concentration. The best morphological observation shows that the PET phases forms well‐defined microfibrils, and CB particles overwhelmingly localize in the surfaces of the PET microfibrils, which led to a very low percolation threshold, i.e., 4.5 phr, and a reasonable conductivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Crystallization, hydrolytic degradation, and mechanical properties of poly (trimethylene terephthalate)/poly(lactic acid) blends

Crystallization, melting, hydrolytic degradation, and mechanical properties of poly(trimentylene terephthalate)/poly(lactic acid) (PTT/PLA) blends have been investigated. The blends show a single and composition-dependent glass-transition temperature (T _g) over the entire composition range, implying that these blends are fully miscible in the amorphous state. The observed T _g is found to increase with increasing PLA content and fitted well with the Gordon–Taylor equation, with the fitting parameter k being 0.91. The cold-crystallization peak temperature increases, while the melt-crystallization peak decreases with increasing the PLA content. Both the pure PTT and PTT/PLA blends cannot accomplish the crystallization during the cooling procedure and the recrystallization occurs again on the second heating. Therefore, on the thermogram recorded, there is exothermal peak followed by endothermal peak with a shoulder. However, to pure PLA, no crystallization takes place during cooling from the melt, therefore, no melting endothermic peak is found on the second heating curve. WAXD analysis indicates PLA and PTT components do not co-crystallize and the crystalline phase of the blends is that of their enriched pure component. With increasing PLA content, the hydrolytic degradation of the blend films increases, while both the tensile strength and the elongation at break of the blend films decrease. That is to say, the hydrolytic degradation of the PTT/PLA blends increases with the introduction of PLA at the cost of the decrease of the flexibility of PTT.     

Reactive blending of aromatic polyesters: Thermal and X‐ray analysis of melt‐blended poly(ethylene terephthalate)/poly(trimethylene terephthalate)

We investigated the reactive melt blending of poly(ethylene terephthalate) (PET) and poly(trimethylene terephthalate) (PTT) in terms of the thermal properties and structural features of the resultant materials. Our main objectives were (1) to investigate the effects of the processing conditions on the nonisothermal melt crystallization and subsequent melting behavior of the blends and (2) to assess the effects of the blending time on the structural characteristics of the transreaction products with a fixed composition. The melting parameters (e.g., the melting temperature, melting enthalpy, and crystallization temperature) decreased with the mixing time; the crystallization behavior was strongly affected by the composition and blending time. Moreover, a significant role was played by the final temperature of the heating treatment; this meant that interchange reactions occurred during blending and continued during thermal analysis. The wide‐angle X‐ray diffraction patterns obtained under moderate blending conditions showed the presence of crystalline peaks of PET and PTT; however, the profiles became flatter after blending. This effect was more and more evident as the mixing time increased. Transesterification reactions between the polyesters due to longer blending times with an intermediate composition led to a new copolymer material characterized by its own diffraction profile and a reduced melting temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Differential scanning calorimetric and free volume study of reactive compatibilization by EPM‐g‐MA of poly(trimethylene terephthalate)/EPDM blends

Differential scanning calorimetry (DSC) and positron annihilation lifetime measurements have been carried out to study the effect of the compatibilizer maleic anhydride grafted ethylene propylene copolymer (EPM‐g‐MA) in poly trimethylene terephthalate and ethylene propylene diene monomer (PTT/EPDM) immiscible blends. The DSC results for the blends of 50/50 and 30/70 compositions show two clear glass transition temperatures, indicating that the blends are two‐phase systems. With the addition of compatibilizer, the separation between the two glass transitions decreased, suggesting an increased interaction between the blend components with compatibilizer. At 5 wt % of compatibilizer, the separation between the T_gs reduced in both 50/50 and 30/70 blends. The positron results for the blends without compatibilizer showed an increase in relative fractional free volume, as the EPDM content in the blend is increased. This suggests the coalescence of free volume of EPDM with the free volumes of PTT due to phase separation. However, the effect of compatibilizer in the blends was clearly seen with the observed minimum in free volume parameters at 5% of the compatibilizer, further suggesting that this percent of compatibilizer seems to be the optimum value for these blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 740–747, 2006     

Morphology and barrier mechanism of biaxially oriented poly(ethylene terephthalate)/poly(ethylene 2,6‐naphthalate) blends

To improve the barrier properties of poly(ethylene terephthalate) (PET), PET/poly(ethylene 2,6‐naphthalate) (PEN) blends with different concentrations of PEN were prepared and were then processed into biaxially oriented PET/PEN films. The air permeability of bioriented films of pure PET, pure PEN, and PET/PEN blends were tested by the differential pressure method. The morphology of the blends was studied by scanning electron microscopy (SEM) observation of the impact fracture surfaces of extruded PET/PEN samples, and the morphology of the films was also investigated by SEM. The results of the study indicated that PEN could effectively improve the barrier properties of PET, and the barrier properties of the PET/PEN blends improved with increasing PEN concentration. When the PEN concentration was equal to or less than 30%, as in this study, the PET/PEN blends were phase‐separated; that is, PET formed the continuous phase, whereas PEN formed a dispersed phase of particles, and the interface was firmly integrated because of transesterification. After the PET/PEN blends were bioriented, the PET matrix contained a PEN microstructure consisting of parallel and extended, separate layers. This multilayer microstructure was characterized by microcontinuity, which resulted in improved barrier properties because air permeation was delayed as the air had to detour around the PEN layer structure. At a constant PEN concentration, the more extended the PEN layers were, the better the barrier properties were of the PET/PEN blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1309–1316, 2006     

Effect of zone drawing on the structure and properties of melt‐spun poly(trimethylene terephthalate) fiber

Melt‐spun poly(trimethylene terephthalate) (PTT) fibers were zone‐drawn and the structures and properties of the fibers were investigated in consideration of the spinning and zone‐drawing conditions. The draw ratio increased up to 4 with increasing drawing temperature to 180°C, at a maximum drawing stress of 220 MPa. Higher take‐up velocity gave lower drawability of the fiber. The PTT fiber taken up at 4000 rpm was hardly drawn, in spite of using maximum drawing stress, because a high degree of orientation had been achieved in the spinning procedure. However, an additional enhancement of birefringence was observed, indicating a further orientation of PTT molecules by zone drawing. The exotherm peak at 60°C disappeared and was shifted to a lower temperature with an increase in the take‐up velocity, which means that the orientation and crystallinity of the fiber increased. The d‐spacing of (002) plane increased with increasing take‐up velocity and draw ratio, whereas those of (010) and (001) planes decreased. In all cases, the crystal size increased with take‐up velocity and draw ratio. The cold‐drawn PTT fiber revealed a kink band structure, which disappeared as the drawing temperature was raised. The physical properties of zone‐drawn PTT fibers were improved as the draw ratio and take‐up velocity increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3471–3480, 2001     

Development and characterization of poly(trimethylene terephthalate)‐based bicomponent meltblown nonwovens

Poly(trimethylene terephthalate) (PTT)‐based mono and bico meltblown webs have been produced by using a Reicofil® Bi‐Component Meltblown Line at TANDEC, located at the University of Tennessee, Knoxville, TN. Thermal and flow properties of PTT were first examined by DSC (differential scanning calorimetry) and with a Melt Indexer for an effective experimental design through the Surface Response Methodology (SRM). The processability of meltblowing in a wide range of operating windows was extensively investigated. Melt temperature, melt throughput, air temperature, airflow rate, and DCD (distance of collector to die) were considered as primary process control variables. The produced webs were characterized for fiber diameter, bulk density, air permeability, hydrostatic head, tensile properties, and heat shrinkage. Non‐round and curly or twisted fibers were observed in the bico PP/PTT webs by SEM (scanning electrical microscope). The PTT grade studied is quite suitable for the meltblown process. The PTT/PP‐based bico webs showed enhanced barrier properties and heat resistance. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1280–1287, 2002