Synthesis and properties of novel hyperbranched polyimides end‐capped with metallophthalocyanines

A fluorinated hyperbranched polyimide (HBPI) is synthesized by using a triamine monomer, 1,3,5‐tris(2‐trifluoromethyl‐4‐aminophenoxy)benzene (TFAPOB) (B₃), as a “core” molecule, 4,4′‐oxydiphthalic anhydride (ODPA) as a A₂ monomer, and 4‐aminophthalonitrile as an end‐capping reagent. After that, a series of novel fluorinated hyperbranched polyimides end‐capped with metallophthalocyanines were prepared by the reactions of dicyanophenyl end‐capped hyperbranched polyimide with excessive amounts of 1,2‐dicyanobenzene and the corresponding metal salt in quinoline. The resulting polyimides containing metallophthalocyanine unites shows optical absorption in the visible region. The absorption bands of the polymers in chloroform solution are in the range of 665–701 nm. These polyimides show glass transition temperatures between 216 and 225°C, and the 5 wt % weight loss temperature of the polymers varied from 440 to 543°C under nitrogen. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Low‐molecular‐weight polytetrafluoroethylene bearing thermally stable perfluoroalkyl end‐groups prepared in supercritical carbon dioxide

Low‐molecular‐weight (M_n) polytetrafluoroethylene (PTFE) homopolymers were successfully prepared using a perfluorodiacyl initiator, bis(perfluoro‐2‐n‐propoxypropionyl) peroxide, in supercritical carbon dioxide. Solid‐state ¹⁹F NMR and Fourier transform infrared spectral analyses show that perfluoroalkyl end‐groups are present in the resultant PTFEs. Thermogravimetric analysis suggests all polymers with various M_n have outstanding thermal stability. Differential scanning calorimetry measurements indicate that both melting and crystallization transitions of PTFE shift to lower temperatures when M_n decreases, because shorter polymer chains can move more easily at lower temperatures. Investigation of polymerization kinetics suggests that the rate law for the polymerization has kinetic orders of 0.5 and 1.0 with respect to initiator and monomer concentrations, indicating that termination occurs through coupling of propagating chains. Melt fusion crystallinity of as‐polymerized PTFE can be as high as 86%, and the polymerization rate does not seem to be obviously affected by the total interphase area of the polymer phase, implying polymerization mainly occurs in the carbon dioxide‐rich fluid phase; meanwhile, the low viscosity and high diffusivity of supercritical carbon dioxide mean that propagating chains have more opportunities to meet, thus yielding low‐M_n PTFEs. Copyright © 2012 Society of Chemical Industry     

Synthesis and properties of organosoluble polyimides based on novel flourene‐ring containing diacetamido‐diamine

A new diacetamido‐diamine monomer, N′‐[7‐(acetyl‐4‐aminoanilino)‐9,9‐dioctylflouren‐2‐yl]‐N′‐4‐aminophenyl) acetamide (ADOAc), with flourene‐based structure was prepared from the reaction of 4‐aminoacetanillide with 2,7‐dibromo‐9,9‐dioctylfluorene in the presence of 10 mol % CuI, 20 mol % N,N′‐dimethylethylene diamine as catalyst and K₂CO₃ as base. Two new flourene‐ring containing polyimides were prepared from the reaction of ADOAc with aromatic dianhydrides such as pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) via chemical imidization of poly(amic acid). The new diamine and the related polyimides were characterized by using conventional methods such as FT‐IR, NMR, and elemental analysis. The polyimides obtained from the reaction of ADOAc with PMDA (PIa) and of ADOAc with BTDA (PIb) had inherent viscosity of 0.49 and 0.58 dL/g respectively, and showed excellent solubility in a variety of organic solvents. The polyimides of PIa and PIb showed excellent thermal stability with 10% weight loss in nitrogen atmosphere at temperatures of 418°C and 407°C and T_g of 172°C and 167°C, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Semiaromatic polyamide poly(hexamethylene terephthalamide)‐co‐polycaprolactam: Thermal and flame‐retardant properties

The poly(hexamethylene terephthalamide)‐co‐polycaprolactam (PA6T/6; 50:50) copolymer was synthesized with a reactive extrusion method and subsequently mixed with a certain content of glass fibers (GFs) and different ratios of flame‐retardant aluminum diethyl phosphinate (AlPi) to fabricate a series of composites. These resulting composites were found to have excellent mechanical (tensile strength = 119–154 MPa) and thermal properties (heat‐deflection temperature = 263–293 °C). It is particularly worth mentioning that the value of the limiting oxygen index reached 29.5% and a UL‐94 V‐0 rating (1.6 mm) was achieved with the addition of 20 portions of AlPi. Also, the values of the peak heat‐release rate and total heat release in cone calorimetry were found to decrease with the addition of the flame‐retardant AlPi, which acted mainly as a flame inhibitor in the gas phase. Through visual observation, scanning electron microscopy after cone calorimetry testing, and thermogravimetric analysis, the condensed‐phase flame‐retardant mechanism of the PA6T/6–GF–AlPi system was confirmed to have a synergetic role. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46451.     

Preparation and characterization of low molecular weight silk fibroin by high‐temperature and high‐pressure method

A low molecular weight silk fibroin powder (LMSF) was prepared through high temperature (200°C) and high pressure (20 kgf/cm²), without any addition of chemicals. The carbonized adducts produced during this process were then removed by treatment with activated charcoal. The yield of LMSF by this preparation method was over 60% after the removal of carbonized adducts by using activated charcoal. Amino acid analysis showed an observable decrease in contents of serine and tyrosine in LMSF prepared by this method, as compared to those prepared by neutral salt. The molecular weight of this LMSF was also observably decreased with an increase in the reaction time. From the measurements of differential scanning calorimeter (DSC) and thermal gravimetric analyzer (TGA), thermal properties of LMSF through high temperature and high pressure were also decreased as compared to those produced by neutral salts. In addition, wide‐angle X‐ray diffraction (WAXD) patterns showed that the crystallinity of LMSF differed from that of the original silk fibroin. It can be said that the preparation method of LMSF in this study is a simple, economical, and environmentally compatible process with many advantages. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2890–2895, 2002     

Synthesis and curing properties of a novel curing agent based on N‐(4‐hydroxyphenyl) maleimide and dicyclopentadiene moieties

A new type of epoxy resin curing agent, containing pendant phenol functions, was synthesized by the free‐radical copolymerization of N‐(4‐hydroxyphenyl) maleimide with dicyclopentadiene (DCPD) monomer in the presence of a radical initiator. The chemical structure was characterized with Fourier transform infrared spectroscopy and nuclear magnetic resonance. The molecular weight of the new curing agent was determined by gel permeation chromatography. The activity and activation energy of this new curing agent with o‐cresol formaldehyde novolac epoxy (CNE) was investigated with a nonisothermal differential scanning calorimetry technique at different heating rates. The thermal properties of the cured polymers were evaluated with thermogravimetric analysis, and the results exhibit good thermal stability. In addition, this new curing agent with CNE showed low moisture absorption because of the hydrophobic nature of the DCPD structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Investigation of thermal behavior of poly(2‐hydroxyethyl methacrylate‐co‐itaconic acid) networks

The thermal behavior of poly(2‐hydroxyethyl methacrylate) [PHEMA] homopolymer and poly(2‐hydroxyethyl methacrylate‐co‐itaconic acid) [P(HEMA/IA)] copolymeric networks synthesized using a radiation‐induced polymerization technique was investigated by differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The glass‐transition temperature (T_g) of the PHEMA homopolymer was found to be 87°C. On the other hand, the T_g of the P(HEMA/IA) networks increased from 88°C to 117°C with an increasing amount of IA in the network system. The thermal degradation reaction mechanism of the P(HEMA/IA) networks was determined to be different from the PHEMA homopolymer, as confirmed by thermogravimetric analysis. It was observed that the initial thermal degradation temperature of these copolymeric networks increased from 271°C to 300°C with IA content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1602–1607, 2007     

Synthesis of a novel benzoxazine‐containing benzoxazole structure and its high performance thermoset

A novel benzoxazine containing benzoxazole structures (Boz‐BOA) was synthesized and its thermoset [P(Boz‐BOA)] was prepared. For comparison, another benzoxazine‐based 4,4′‐diamine diphenyl methane (Boz‐MDA) was also synthesized using a simplified procedure. The structure of Boz‐BOA and Boz‐MDA was confirmed by Fourier transform infrared (FTIR) and ¹H‐NMR. Using FTIR and differential scanning calorimetric scans method, the curing behavior of Boz‐BOA was probed, and the structure of P(Boz‐BOA) was addressed, which was similar to that of P(Boz‐MDA). Data of dynamic mechanical analysis showed that P(Boz‐BOA) exhibited a better modulus retention at high temperature than P(Boz‐MDA), which was attributed to benzoxazole structure restricting the mobility of chains, even at high temperature. P(Boz‐BOA) also exhibited high glass transition temperature (T_g), excellent thermal stability, and low coefficient of thermal expansion value at wide temperature range. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

New polymer syntheses part: 54 novel conducting polymers and copolymers based on 4‐Teriary butyl‐cyclohexanone moiety in the main chain

A new interesting class of conducting polymer and copolymers based on 4‐teriary butyl‐cyclohexanone in the main chain has been synthesized by solution polycodensation of terephthalaldehyde with 4‐teriary butyl‐cyclohexanone and/or cycloalkanone derivatives. The model compound I was synthesized from the 4‐teriary butyl‐cyclohexanone with benzaldehyde, and its structure was confirmed by elemental and spectral analyses. The resulting polymer and copolymers were characterized by elemental and spectral analyses including Fourier transform infrared spectrometer (FT‐IR) and nuclear magnetic resonance (¹H‐NMR), beside solubility and viscometry measurements. The thermal properties of those polymer and copolymers were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) measurements and correlated to their structural units. X‐ray analysis showed that it has some degree of crystallinity in the region 2θ = 5–60°. The UV–visible spectra of some selected polymers were measured in dimethyl sulfoxide (DMSO) solution and showed absorption bands in the range 253–398 nm, due to n–π* and π–π* transition. The morphological properties of selected examples were tested by scanning electron microscope (SEM). Moreover, the electrical conductivities and the doping with iodine were tested. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Novel adamantane‐containing epoxy resin

A novel adamantane‐containing epoxy resin diglycidyl ether of bisphenol‐adamantane (DGEBAda) was successfully synthesized from 1,3‐bis(4‐hydroxyphenyl)adamantane by a one‐step method. The proposed structure of the epoxy resin was confirmed with Fourier transform infrared, ¹H‐NMR, gel permeation chromatography, and epoxy equivalent weight titration. The synthesized adamantane‐containing epoxy resin was cured with 4,4′‐diaminodiphenyl sulfone (DDS) and dicyandiamide (DICY). The thermal properties of the DDS‐cured epoxy were investigated with differential scanning calorimetry and thermogravimetric analysis (TGA). The dielectric properties of the DICY‐cured epoxy were determined from its dielectric spectrum. The obtained results were compared with those of commercially available diglycidyl ether of bisphenol A (DGEBA), a tetramethyl biphenol (TMBP)/epoxy system, and some other associated epoxy resins. According to the measured values, the glass‐transition temperature of the DGEBAda/DDS system (223°C) was higher than that of the DGEBA/DDS system and close to that of the TMBP/DDS system. TGA results showed that the DGEBAda/DDS system had a higher char yield (25.02%) and integral procedure decomposition temperature (850.7°C); however, the 5 wt % degradation temperature was lower than that of DDS‐cured DGEBA and TMBP. Moreover, DGEBAda/DDS had reduced moisture absorption and lower dielectric properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

A novel polyacrylamide‐based superabsorbent with temperature switch for steam breakthrough blockage

A novel high‐temperature resistant superabsorbent polymer (SAP) with a temperature switch to control its water absorbency was prepared through solution polymerization of acrylamide (AM), using N,N‐methylenebisacrylamide (NMBA) and tetraallylammonium chloride (TAAC) as crosslinking agents. The SAPs were structurally characterized by Fourier transform infrared (FTIR) spectroscopy and energy dispersive X‐ray spectroscopy (EDX). The factors that influence the water absorbency such as total crosslinker concentration, molar ratio of NMBA to TAAC and temperature were investigated. The SAP with optimized crosslinker concentration showed a swelling ratio less than 10 g/g at 25°C, and drastically enhanced water absorption capacity (190 g/g) at 300°C. The water absorption characteristics can be tuned by varying the temperature. Swelling experimental results combined with crosslinking density study and morphology observation by scanning electron microscopy (SEM) clearly demonstrated that the hydrolysis of amide bonds on NMBA played a critical role in creating these previously unreported SAPs, and that the use of TAAC with an appropriate amount rendered the SAPs high‐temperature resistance. This kind of SAPs has high application potentials as plugging material for steam breakthrough and channeling in heavy oil reservoirs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42067.     

Polyethylene‐montmorillonite nanocomposites obtained by in situ polymerization of ethylene with nickel‐diimine catalysts

Nanocomposites of exfoliated montmorillonite in polyethylene were obtained using a combination of 1,4‐bis(2,6‐diisopropylphenyl)‐acenaphthenediimine‐dichloro‐nickel(II), montmorillonite, and methylalumoxane (MAO) or trimethylaluminum (TMA) to polymerize ethylene. The properties of the polymers were strongly influenced by the amount of clay they contained. The addition of 2.5% commercial montmorillonite (KSF or Cloisite 15A) enhanced the storage modulus from 5 to 878 MPa. Transmission electron microscopy (TEM) analyses provided evidence of exfoliation of the montmorillonite with the formation of a polyethylene nanocomposite. The enhanced mechanical properties were explained as a consequence of the reinforcement due to the presence of nanoscale layers formed from exfoliation of the clay included in the polyethylene matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of Schiff‐base‐containing polyimides

Benzyl bisthiosemicarbazone and its complexes with nickel (NiLH₄) and copper (CuLH₄) were used as diamine monomers for the synthesis of new Schiff‐base polyimides. The solution polycondensation of these monomers with the aromatic dianhydrides afforded metal‐containing Schiff‐base polyimides with inherent viscosities of 0.98–1.33 dL/g (measured in N‐methyl‐2‐pyrrolidone at 25°C). The polyimides were generally soluble in a wide range of solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, tetrahydrofuran, dimethyl sulfoxide, tetrachloroethane, hexamethylene phosphoramide, N‐methyl‐2‐pyrrolidone, ethyl acetate, and pyridine at room temperature. The initial degradation temperatures of the resultant polyimides fell in the range of 220–350°C in nitrogen with char yields ranging from 36 to 64% at 700°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Dopamine‐functionalized poly(vinyl alcohol) elastomer with melt processability and self‐healing properties

A dopamine‐functionalized poly(vinyl alcohol) (PVA) elastomer with melt processability and self‐healing properties was prepared by a new chemical route of graft modification, that is, PVA carboxylation and a carbodiimide reaction. The conventional modifier for PVA sacrificed the intrinsic hydrogen‐bonding interactions and dramatically decreased the mechanical strength. The modifier dopamine, as a catechol derivative, has two hydroxyl groups, which formed hydrogen bonds with the hydroxyl groups of PVA; it also has one benzene ring, which increased the thermal stability. We found that the introduction of dopamine into the PVA molecular structure lowered the melting point, improved the thermal stability, broke the crystalline structure, and enabled thermal processing. Moreover, the modified PVA possessed good mechanical properties, could be self‐healed, and is believed to have potential applications in many fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45072.     

Polyethylene catalytic hydrocracking by PtHZSM‐5, PtHY,and PtHMCM‐41

The mechanisms involved in polyethylene catalytic hydrocracking are investigated by monitoring temperature‐dependent evolution profiles derived from mass spectra obtained while polymer/catalyst samples were heated at a constant rate. Repetitive injection gas chromatography/mass spectrometry (GC/MS) results are used to identify class‐specific fragment ions that represent paraffins, olefins, and alkyl aromatics. Class‐specific ion signals are used to generate isoconversion‐effective activation energy plots from which mechanistic comparisons are made. Studies using PtHZSM‐5, PtHY, and PtHMCM‐41 bifunctional solid acid catalysts in helium and hydrogen are reported. The effects of hydrogen on polyethylene cracking are dramatic and result in significant changes to isoconversion‐effective activation energies. Catalytic cracking mechanisms for the three catalysts are compared and differences are explained by a combination of pore size and acidity effects. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1293–1301, 2004     

Synthesis and characterization of organic–inorganic hybrid polymers with a well‐defined structure from diamines and epoxy‐functionalized polyhedral oligomeric silsesquioxanes

A new class of organic‐inorganic hybrid polymers with well‐defined structure was prepared by reacting diepoxyhexavinyl polyhedral oligomeric silsesquioxanes (DehvPOSS) with diamines of different chain lengths. The structures and properties of these hybrid polymers were well characterized by FTIR, ²⁹Si‐NMR, GC‐MS, and TGA. A modeling characterization was employed to help identify the structures of organic tethers linked between the POSS cages. The results indicated that at the stoichiometric ratio of DehvPOSS to diamine, well‐defined organic–inorganic hybrid polymers with controlled variation of the organic tether architecture can be made, and each organic tether connected four POSS cages. Thermal stability (T_dec) increased with an increase in the tether length of the diamine molecules, and the highest T_dec was obtained with butanediamine (rather than propanediamine or ethanediamine) as the organic tether. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3730–3735, 2006     

Efficient preparation of novel fluoroalkyl end‐capped oligomers/titanium dioxide nanocomposites

Novel fluoroalky end‐capped oligomers/titanium dioxide nanocomposites were prepared by the hydrolysis of titanium isopropoxide in the presence of fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomer [R_F‐(DOBAA)_n‐R_F], fluoroalkyl end‐capped N,N‐dimethylacrylamide oligomer [R_F‐(DMAA)_n‐R_F], and fluoroalkyl end‐capped acrylic acid oligomer [R_F‐(ACA)_n‐R_F] in tetrahydrofuran under mild conditions. In these fluorinated oligomers, R_F‐(ACA)_n‐R_F oligomer is more effective for the preparation of the corresponding oligomers/titanium dioxide nanocomposites, and this oligomer can afford the expected fluorinated titanium dioxide nanocomposites in higher isolated yields. In addition, R_F‐(ACA)_n‐R_F/titanium dioxide composites are nanometer size‐controlled very fine nanoparticles (14–48 nm), and exhibited a good dispersibility not only in water but also in traditional organic solvents. Fluoroalkyl end‐capped oligomers/titanium dioxide nanocomposites were also applied to the surface modification of the common organic polymers such as poly(methyl methacrylate) to exhibit a good oleophobic and hydrophilic characteristics on the surface. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers.     

Synthesis,characterization, and thermodynamic properties of poly(3‐mesityl‐2‐hydroxypropyl methacrylate)

Poly(3‐mesityl‐2‐hydroxypropyl methacrylate) (PMHPMA) was synthesized in a 1,4‐dioxane solution with 2,2′‐azobisisobutyronitrile as the initiator at 60°C. The homopolymer and its monomer were characterized with ¹H‐ and ¹³C‐NMR, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, size exclusion chromatography, and elemental analysis techniques. According to size exclusion chromatography analysis, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of PMHPMA were 65,864 g/mol, 215,375 g/mol, and 3.275, respectively. According to thermogravimetric analysis, the carbonaceous residue value of PMHPMA was 14% at 500°C. The values of the specific retention volume, adsorption enthalpy, sorption enthalpy, sorption free energy, sorption entropy, partial molar free energy, partial molar heat of mixing, weight fraction activity coefficient of solute probes at infinite dilution (Ω), and Flory–Huggins interaction parameter (χ) were calculated for the interactions of PMHPMA with selected alcohols and alkanes by the inverse gas chromatography method at various temperatures. According to Ω and χ, selected alcohols and alkanes were nonsolvents for PMHPMA at 423–453 K. Also, the solubility parameter of PMHPMA (δ₂) was found to be 24.24 and 26.33 (J/cm³)^0.5 from the slope and intercept of (δ/RT) ? χ/V₁ = (2δ₂/RT)δ₁ ? δ/RT at 443 K, respectively [where δ₁ is the solubility parameter of the probe, V₁ is the molar volume of the solute, T is the column temperature (K), and R is the universal gas constant]. The glass‐transition temperature of PMHPMA was found to be 386 and 385 K by inverse gas chromatography and differential scanning calorimetry techniques, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 101–109, 2006     

Synthesis and performance of a novel nitrogen‐containing cyclic phosphate for intumescent flame retardant and its application in epoxy resin

A novel nitrogen‐containing cyclic phosphate (NDP) was synthesized and well characterized by ¹H, ¹³C, ³¹P NMR, mass spectra and elemental analysis. NDP was used as an additive intumescent flame retardant (AIFR) to impart flame retardancy and dripping resistance for diglycidyl ether of bisphenol‐A epoxy resin (DGEBA) curied by 4,4′‐diaminodiphenylsulfone (DDS) with different phosphorus content. The flammability, thermal stability, and mechanical properties of NDP modified DGEBA/DDS thermosets were investigated by UL‐94 vertical burning test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Izod impact strength and flexural property tests. The results showed that NDP modified DGEBA/DDS thermosets exhibited excellent flame retardancy, moderate changes in glass transition temperature and thermal stability. When the phosphorus content reached only 1.5 wt %, the NDP modified DGEBA/DDS thermoset could result in satisfied flame retardancy (UL‐94, V‐0). The TGA curves under nitrogen and air atmosphere suggested that NDP had good ability of char formation, and there existed a distinct synergistic effect between phosphorus and nitrogen. The flame retardant mechanism was further realized by studying the structure and morphology of char residues using FT‐IR and scanning electron microscopy (SEM). It indicated that NDP as phosphorus‐nitrogen containing flame retardant worked by both of the condensed phase action and the vapor phase action. Additionally, the addition of NDP decreased slightly the flexural strength of the flame retarded DGEBA epoxy resins, and increased the Izod impact strength of these thermosets. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41859.     

Modeling the tensile behavior of ultra‐high‐molecular‐weight polyethylene with a novel flow rule

A study of the tensile behavior of ultra‐high‐molecular‐weight polyethylene over a range of strain rates showed that its strain rate sensitivity was a function of the strain. This was related to a flow rule developed for this material in a previous study on compressive behavior. This flow rule is an adaptation of that of Hill, in which the anisotropy coefficients are power‐law functions of the extension ratios. It is used in conjunction with an Eyring process. The observed rate dependence of the tensile behavior conformed with that obtained with the power‐law flow rule and could be used to derive a value of the power‐law coefficient. Independent observations were made of the relationship between the axial and transverse strains in tensile specimens with inhomogeneous strain fields. A constitutive model was developed that incorporates the new flow rule and was implemented in a finite element analysis. When this analysis was used to model the inhomogeneous tensile specimens, it gave predictions of the axial and transverse strain that were consistent with the experiment when the power‐law coefficient was the same value as that derived from the study of the rate dependence. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011