Melt viscoelasticity of polyethylene terephthalate resins for low density extrusion foaming

The rheological properties of conventional polyethylene terephthalate (PET) resins are not particularly suitable for low density extrusion foaming with physical blowing agents; as a result, chemically modified resins through chain extension/branching reactions are often used. Such resins have overall higher melt viscosity and higher melt strength/melt “elasticity” than unmodified materials. In this work, following a review of the prior art on PET chemical modification, an unmodified and a chemically modified resin were selected and characterized for their melt viscoelastic properties including shear and dynamic complex viscosity over a broad shear rate/frequency range, storage and loss modulus, and die swell. Certain rheological models were found to provide better fits of the entire viscosity curve for the unmodified vs. the modified resin. Foamed extrudates having variable densities (from about 1.2 to 0.2 g/cc), were prepared by carbon dioxide injection in monolayer flat sheet extrusion equipment. Foams with increasingly lower density, below 0.5 g/cc, were obtained by increasing gas pressure only in the case of the chemically modified resin. The effects of variables such as concentration of the physical blowing agent, resin rheology, resin thermal properties and choice of process conditions are related to product characteristics including density, cell size and crystallinity.     

Influence of molecular structure on the rheological and processing behavior of polyethylene resins

The rheological and processing behavior (melt fracture performance) of linear lowdensity polyethylenes (LLDPEs) is studied as a function of both the weight average molecular weight (M_w) and its distribution (MWD). A number of LLDPE resins having different molecular characteristics were tested, with essentially one characteristic (M_w or MWD) changing at a time. The first series of resins consisted of nine samples having a wide range of polydispersities (3.3–12.7) and nearly constant M_w and short chain branching. The second series had six resins with varying M_w (51,000–110,000) but fixed MWD (about 4). The influence of M_w and MWD on the viscosity profiles, linear viscoelastic moduli as expressed by means of a discrete spectrum of relaxation times, extrudate swell, and melt fracture behavior for these resins is reported. Correlations between the molecular characteristics of the resins and their rheological and processing behavior are also reported. It is found that for a given molecular weight, the optimum melt fracture performance is obtained at a specific polydispersity value, and it is characterized by a minimum relaxation time for the resin defined in terms of recoverable shear.     

Modification of cyanate ester resin by poly(ethylene phthalate) and related copolyesters

Aromatic polyesters were prepared and used to improve the brittleness of the cyanate ester resin. The aromatic polyesters include poly(ethylene phthalate) (PEP) and poly(ethylene phthalate‐co‐1,4‐phenylene phthalate). The polyesters were effective modifiers for improving the brittleness of the cyanate ester resin. For example, inclusion of 20 wt % PEP (MW 19,800) led to a 120% increase in the fracture toughness (K_IC) with retention in flexural properties and a slight loss of the glass transition temperature compared to the mechanical and thermal properties of the unmodified cured cyanate ester resin. The microstructures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resins was lower than that of the unmodified resin as determined by thermogravimetric analysis. The water absorptivity of the modified resin increased significantly, compared to that of the unmodified cured cyanate ester resin. The toughening mechanism was discussed in terms of the morphological and dynamic viscoelastic behaviors of the modified cyanate ester resin system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 208–219, 2000     

Preparation of long‐chain branched poly(ethylene terephthalate): Molecular entanglement structure and toughening mechanism

Poly(ethylene terephthalate) (PET) was long‐chain branched (LCB) by ring‐opening reaction with both pyromellitic dianhydride and tetrahydrophthalic acid diglycidyl ester as chain extenders through reactive melt processing. It was found that with the increase of chain extenders dosage, the intrinsic viscosity of PET increased and melt index decreased greatly, while both the tensile strength and impact strength of PET were remarkably improved. The elastic modulus (G′) and viscous modulus (G″) were enhanced by chain branching. Compared with PET, the complex viscosities of LCB‐PET were much higher at full frequency range, and obvious shear thinning was presented. The Cole–Cole curve deviated from the semicircular shape and the curve end was inclined to upward in high viscosity region, indicating the formation of the multiple hierarchical structures. The molecular weight of the branch (M_B) was much greater than critical entanglement molecular weight (M _e), which essentially confirmed the existence of LCB structure and fairly strong molecular entanglement in the LCB‐PET molecular chain. When subjected to external force, the entanglement point, acting as physical crosslinking point between the molecules, was in favor of increasing the molecular interaction, reducing the molecular slippage, and bearing a large deformation. POLYM. ENG. SCI., 59:1190–1198 2019. © 2019 Society of Plastics Engineers     

Synthesis and properties of vinyl siloxane modified cresol novolac epoxy for electronic encapsulation

Vinyl siloxane (VS) modified cresol novolac epoxy (CNE) and cresol novolac hardener (CNH) resins are synthesized and both components are capable of further crosslinking. The reaction kinetics for both components are studied so that they can crosslink simultaneously in a designed synthesis procedure. Through careful adjustment of a triphenylphosphine dosage, the glass‐transition temperature (T_g) of CNE/CNH resins can be effectively controlled. Phenomena characteristic of the existence of a diffusion‐controlled reaction are also observed. The relationships between the T_g and crosslinking density for the CNE/CNH resin are explicitly revealed through gel content and swell ratio experiments. CNE/CNH resins with a higher T_g have lower equilibrium moisture uptake because of the higher fraction of free volume. The coefficient of diffusion also shows a similar but less apparent trend. The incorporation of VS incurs a 35% reduction in the equilibrium moisture uptake and a 20% reduction in the coefficient of diffusion for the modified resin. The VS‐modified CNE/CNH resin possesses a lower Young's modulus and a higher strain at break than its unmodified counterpart does. This modified resin can help to alleviate the popcorning problems in integrated circuit packages, which results from hygrothermal stresses. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 652–661, 2001     

Modification of bismaleimide resin by poly(propylene phthalate), poly(butylene phthalate) and related (co)polyesters

Aromatic polyesters were prepared and used to decrease the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane (BMI) and o,o′-diallyl bisphenol A (DBA) (Matrimid 5292 resin). The aromatic polyesters included poly(propylene phthalate) (PPP), poly(2,2-dimethylpropylene phthalate) (PDPP), poly(butylene phthalate) (PBP) and poly(butylene phthalate-co-butylene terephthalate) (50mol% terephthalate unit) (PBPT). The polyesters were effective modifiers for decreasing the brittleness of the bismaleimide resin. For example, inclusion of 20wt% PPP (MW 18700) led to 50% increase in the fracture toughness (K_IC) with retention of flexural properties and a slight loss of the glass transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin. Micro-structures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resins was slightly lower than that of the unmodified resin as determined by thermogravimetric analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviour of the modified bismaleimide resin system. © 1998 SCI.     

Molecular and structural analysis of epoxide‐modified recycled poly(ethylene terephthalate) from rheological data

A multifunctional epoxide chain extender (ADR4370S) was used to increase the molecular weight of recycled poly(ethylene terephthalate) (R‐PET). The extension processing was carried out by melt mixing reaction. The effects of ADR4370S content on the molecular structure [molecular weight, molecular weight distributions (MWDs), branching, and gel‐like structures] of modified R‐PET were rheologically investigated. The results showed that the complex and apparent viscosity of the modified R‐PET were larger than those of unmodified one. The solid‐like behavior of R‐PET was enhanced after the reactive modification. The increments of balancing torque, reaction peak, and shear‐thinning behavior became more pronounced by increasing the concentration of ADR4370S. Reactive modification was characterized by the presence of long‐chain branching resulted in a wider MWD. Modified Cole–Cole plots demonstrated a shift toward higher storage modulus values at a given loss modulus value for the modified R‐PET samples. High concentration of ADR4370S (>1.5 wt%) resulted in a polymeric structure near the sol–gel transition point whose linear viscoelastic properties obeyed scaling law. The relaxation time was prolonged with the amount of ADR4370S increase. The decrease in the melt point and crystallization temperature of the modified R‐PET was correlated to the presence of chain branching. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Bottle‐to‐bottle recycling of PET via nanostructure formation by melt intercalation in twin screw compounder: Improved thermal,barrier, and microbiological properties

Attempts have been made to modify the properties of the injection processing‐scraped PET (denoted as RPET) via intercalation with different levels of organically modified nanoclay (montmorillonite) by melt blending in a corotating twin screw compounder. The clay platelets dispersion state has been qualitatively correlated with the melt linear viscoelastic as well as tensile and barrier properties of the prepared nanocomposites. Oxygen permeation of the nanocomposite PET films showed significant reduction compared with the pristine PET polymer. All the PET/nanoclay composites exhibited no bacterial growth, with no potentiality to generate acetaldehyde, as measured by GC/Mass analyzer. X‐ray diffractometry and transmission electron microscopy performed on the scraped PET/organoclay nanocomposite samples showed increase in d₀₀₁ spacing of the clay layers and their dispersion throughout the PET matrix. Differential scanning calorimetry analysis showed higher crystallization temperature as well as crystallization enthalpy (ΔH_c) for the nanocomposite samples, compared with the unprocessed virgin PET. The RPET nanocomposite samples composed of 3 and 5% of nanoclay exhibited enhanced melt elastic modulus and pseudosolid‐like behavior at low shear frequencies measured by rheomechanical spectroscopy than the unfilled pristine‐scraped PET, indicating the formation of nanoscopic network structure by the clay platelets, which leads to the development of nanostructured resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Reactive processing of LLDPES in corotating intermeshing twin-screw extruder. II. Effect of peroxide treatment on processability

Commercial ethylene–octene linear low-density polyethylenes (LLDPEs) were reactively extruded with low levels of a peroxide [2,5-dimethyl-2,5-di(t-butylperoxy)hexane] to modify polymer molecular structure and processing properties. Peroxide levels were kept low to avoid crosslinking. This article reports the effects of this reactive extrusion on viscoelastic properties. Rheological properties are more sensitive than are molecular structure characteristics to the changes produced by reactions of very low peroxide concentrations. Complex viscosity increases are seen, especially at low frequencies. Shear-thining behavior is also accentuated. The crossover between G′ and G″ moves to lower frequencies. A modified Cole–Cole presentation of these data shows that the elastic component is more predominant for extrusion-reacted materials. Peroxide-modified materials all have higher Bagley end correction values than those of barefoot resins. The former exhibit lower power indices (more shear thinning). All these properties indicate more long-chain branching and higher melt elasticity. However, die swell decreased as a function of peroxide concentration. Peroxide treatment results in an enhancement of elongational viscosity, both under isothermal and cooling conditions, along with a decrease in drawdown ability. The rheological changes parallel those reported earlier in molecular characteristics but are more sensitive and suitable to evaluate the effects of reactive processing. The effectiveness of the reactive extrusion process for improving processability of LLDPEs depends critically on the extrusion conditions. © 1995 John Wiley & Sons, Inc.     

Toughening of cyanate ester resin by N‐phenylmaleimide–N‐(p‐hydroxy)phenyl‐maleimide–styrene terpolymers and their hybrid modifiers

N‐Phenylmaleimide–N‐(p‐hydroxy)phenylmaleimide–styrene terpolymer (HPMS), carrying reactive p‐hydroxyphenyl groups, was prepared and used to improve the toughness of cyanate ester resins. Hybrid modifiers composed of N‐phenylmaleimide–styrene copolymer (PMS) and HPMS were also examined for further improvement in toughness. Balanced properties of the modified resins were obtained by using the hybrid modifiers. The morphology of the modified resins depends on HPMS structure, molecular weight and content, and hybrid modifier compositions. The most effective modification of the cyanate ester resin was attained because of the co‐continuous phase structure of the modified resin. Inclusion of the modifier composed of 10 wt% PMS (M_w 136 000 g mol^?1) and 2.5 wt% HPMS (hydroxyphenyl unit 3 mol%, M_w 15 500 g mol^?1) led to 135% increase in the fracture toughness (K_IC) for the modified resin with a slight loss of flexural strength and retention of flexural modulus and glass transition temperature, compared with the values for the unmodified resin. Furthermore, the effect of the curing conditions on the mechanical and thermal properties of the modified resins was examined. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviour of the modified cyanate ester resin system. © 2001 Society of Chemical Industry     

Toughening of cyanate ester resin by N‐phenylmaleimide–styrene copolymers

The N‐phenylmaleimide–styrene copolymer (PMS) was prepared and used to improve the brittleness of the cyanate ester resin. PMS was an effective modifier for improving the brittleness of the resin. The morphologies of the modified resins depended on PMS molecular weight and content. The most effective modification of the cyanate ester resin was attained because of the cocontinuous phase structure of the modified resin. Inclusion of 10 wt % PMS (M_w 133,000) led to an 160% increase in the fracture toughness (K_IC) for the modified resin with a slight loss of flexural strength and retention of flexural modulus and the glass transition temperature, compared to the values for the unmodified resin. Low water absorptivity of the parent‐cured resin was not deteriorated by modification. The toughening mechanism was discussed in terms of the morphological and dynamic viscoelastic behaviors of the modified cyanate ester resin system. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2931–2939, 1999     

Effect of sparse long‐chain branching on the step‐strain behavior of a series of well‐defined polyethylenes

The effect of sparse long chain branching, LCB, on the shear step‐strain relaxation modulus is analyzed using a series of eight high‐density polyethylene (HDPE) resins. Strains of 1 to 1250% are imposed on materials with LCB content ranging from zero to 3.33 LCB per 10,000 carbon atoms. All materials are observed to obey time–strain separation beyond some characteristic time, τ_k. The presence of LCB is observed to increase the value of τ_k relative to the linear resin. The behavior of the relaxation modulus at times shorter than τ_k is investigated by an analysis of the enhancement seen in the linear relaxation modulus, G⁰(t), as a function of strain and LCB content. This enhancement is seen to (1) increase with increasing strain in all resins, (2) be significantly larger in the sparsely branched HDPE resins relative to the linear HDPE resin, and (3) increase in magnitude with increasing LCB content. The shape and smoothness of the damping function is also investigated. The finite rise time to impose the desired strain is compared to the Rouse relaxation time of linear HDPE resins studied. Sparse LCB is found to increase the magnitude of the relaxation modulus at short times relative to the linear resin. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Improving the heat‐resistance and toughness performance of phenolic resins by adding a rigid aromatic hyperbranched polyester

An aromatic hyperbranched polyester (AHBP) was synthesized by melt polycondensation from diphenolic acid and characterized by Fourier transform infrared spectrum (FTIR) spectra. The degree of branching (DB) value of AHBP calculated from the ¹³C‐NMR spectroscopy was 0.67. The number‐average molecular weight (M_n) and weight‐average molecular weight (M_w) of AHBP were 1792 and 4480 g/mol, respectively. Novel phenolic resins modified with AHBP (PR/AHBP) were then prepared, in which AHBP was used as toughener of phenolic resins. The effect of AHBP on the thermal properties of phenolic resins was studied by means of differential scanning calorimetry (DSC), thermal gravimetric analyses (TGA), and heat deformation temperature tests. The modified resins presented higher glass transition temperature (T_g) than the unmodified system due to that the rigid backbone structure of AHBP with a great deal of the benzene ring groups restricted the mobility of the chain segments of macromolecules. The DSC, scanning electron microscopy (SEM) analyses showed that AHBP had good compatibility with phenolic resin, and the modified resins showed ductile fracture. The results of mechanical performance measurements exhibited that the impact strength of PR/AHBP containing 15 wt % AHBP was about 130% higher than that of the neat phenolic resin, suggesting that the toughness of PR/AHBP was significantly improved by the addition of AHBP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42734.     

Modification of bismaleimide resin by soluble poly(ester imide) containing trimellitimide moieties

Poly(ester imide)s containing trimellitimide moieties have been used to reduce the brittleness of the bismaleimide resin composed of 4,4′‐bismaleimidediphenyl methane and o,o′‐diallyl bisphenol A. The poly(ester imide)s include poly[ethylene phthalate‐co‐ethylene N‐(1,4‐phenylene)trimellitimide dicarboxylate]s containing 20–40 mol% trimellitimide (TI) unit, and poly[trimethylene phthalate‐co‐trimethylene N‐(1,4‐phenylene)trimellitimide dicarboxylate]s (PESIP) containing 20 mol% TI unit. The poly(ester imide)s are effective modifiers for reducing the brittleness of the bismaleimide resin. For example, when using 30 wt% of PESIP (20 mol% TI unit, M_w 13 500 g mol^?1), the fracture toughness (K_IC) for the modified resin is increased by 80% with retention in flexural properties and a slight loss of the glass transition temperature, compared with the values of the unmodified cured bismaleimide resin. Microstructures of the modified resins have been examined by scanning electron microscopy and dynamic viscoelastic analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviour of the modified bismaleimide resin system. © 2004 Society of Chemical Industry     

Studies on modified phenolic resin. Iv: Properties of phenolic resin modified with 4-hydroxyphenyl- maleimide/n-butylacrylate copolymers

Three 4-hydroxyphenylmaleimide/ n-butylacrylate (HPMI/n-BuA) copolymers with different monomer ratios were synthesized. Their average molecular weights, glass transition temperatures (T,_g), and thermal decomposition temperatures were measured. It was found that these copolymers had higher average molecular weights and higher thermal decomposition temperatures than novolac. Modified phenolic resins were prepared by transfer moulding from moulding compounds consisting of novolac, the copolymer, hexamethylenetetramine (hexamine), and glass fibre. Properties of the three kinds of modified phenolic resins were examined by flexural test, impact test, dynamic thermomechanometry, and observation of morphology. It was found that phenolic resin modified with HPMI/ n-BuA (1/3-6) copolymer and modified with HPMI/n-BuA (1/7-0) copolymer showed good toughness and good heat resistance. It was also found that the heat resistance of modified phenolic resins was improved by after-cure, but the mechanical properties were decreased by after-cure: similar behaviour was observed for unmodified phenolic resin.     

Microporous membranes of isotactic poly(4‐methyl‐1‐pentene) from a melt‐extrusion process. I. Effects of resin variables and extrusion conditions

A study utilizing isotactic poly(4‐methyl‐1‐pentene) (PMP) was undertaken to investigate a three‐stage process (melt‐extrusion/annealing/uniaxial‐stretching) (MEAUS) employed to produce microporous films. The results of this study will be reported in the course of two articles. In this first part, three PMP resins were melt‐extruded into tubular films (blowup ratio; BUR = 1), where the resins each differ in weight‐average molecular weight (M_w). Specific attention was focused upon the morphological and crystal orientation results as a function of the melt‐relaxation times as influenced by the resin characteristics and the processing parameters. The results of a number of melt‐extrusion conditions are presented. A stacked lamellar morphology was obtained in each case; however, the type of stacked lamellar morphology, planar or twisted, and the orientation state was found to depend upon both the resin characteristics, specifically M_w, and the melt‐extrusion conditions. Atomic force microscopy and wide‐angle X‐ray scattering (WAXS) were the main techniques utilized to study the melt‐extruded films, while oscillatory shear measurements, in conjunction with a Carreau–Yasuda analysis, aided in differentiating the melt‐flow behavior of the three resins. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2095–2113, 2002     

Modification of Acid Anhydride-cured Epoxy Resins By N-Phenyl- maleimide–Styrene Copolymers and N-Phenylmaleimide–Styrene– p-Hydroxystyrene Terpolymers

N-Phenylmaleimide–styrene copolymers (PMS) and reactive N-phenylmaleimide–styrene–p-hydroxystyrene (HSt) terpolymers (PMSH) containing p-hydroxyphenyl groups were used to improve the toughness of bisphenol A diglycidyl ether epoxy resin cured with methyl hexahydrophthalic anhydride. PMS and PMSH were effective modifiers for epoxies. The morphologies of the modified resins depended on modifier structure and content. The most effective modification for the cured resins was attained because of the co-continuous structure of the modified resins in both PMS and PMSH modification systems. When using 15wt% of PMS (M¯_w 125000), the fracture toughness, K_IC, for the modified resin increased by 230%, with retention of flexural modulus and glass transition temperature, but with a loss of flexural strength, compared with the values for the unmodified epoxy resin. When using PMSH as the reactive modifier, the efficiency decreased with increase in HSt content, because of the increasing extent of dispersion of the PMSH-rich continuous phases. In the modification with 10wt% PMSH (1·0mol% HSt unit, M¯_w 294000), the modified resin had balanced physical properties. © of SCI.     

Modification of epoxy resins with poly(aryl ether ketone)s

Poly(aryl ether ketone)s were used as modifiers for bisphenol-A diglycidyl ether epoxy resin (AER 331) cured with methyl hexahydrophthalic anhydride. Poly(phthaloyl diphenyl ether) (PPDE), soluble in the uncured epoxy resin without using solvents, was prepared by the Friedel-Crafts reaction of phthaloyl chloride and diphenyl ether. The mechanical, thermal, and dynamic viscoelastic properties of the modified resins with PPDE were examined and compared to the parent resin (AER 331). The fracture toughness, K_IC, for the modified resins increased at no expense to their mechanical and thermal properties on 10 wt % addition of PPDE with molecular weights of more than 17,000. The toughening mechanism is discussed based on the morphological and dynamic viscoelastic behaviors of the modified epoxy resin system.     

Toughening of bismaleimide resin by modification with poly(ethylene phthalate) and poly(ethylene phthalate-co-ethylene isophthalate)

Aromatic polyesters were prepared and used to improve the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane and o,o′-diallyl bisphenol A. The aromatic polyesters contain poly(ethylene phthalate) (PEP) and poly(ethylene phthalate-co-ethylene isophthalate) (10 mol % isophthalate unit) (PEPI). PEP and PEPI were effective modifiers for improving the brittleness of the bismaleimide resin. The most suitable composition for the modification of the bismaleimide was inclusion of 20 wt % PEP (MW 18,200), which led to an 80% increase in the fracture toughness with retention of flexural properties and a slight decrease in the glass transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin (Matrimid resin). Microstructures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resin was slightly lower than that of the unmodified resin by thermogravimetric analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behavior of the modified bismaleimide resin system. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1349–1357, 1997     

Melt rheology and properties of compatibilized recycled poly(ethylene terephthalate)/(styrene‐ethylene‐ethylene‐propylene‐styrene) block copolymer blends

Blends of recycled poly(ethylene terephthalate) (R‐PET) and (styrene‐ethylene‐ethylene‐propylene‐styrene) block copolymer (SEEPS) compatibilized with (maleic anhydride)‐grafted‐styrene‐ethylene‐butylene‐styrene (SEBS‐g‐MAH) were prepared by melt blending. The compatibilizing effects of SEBS‐g‐MAH were investigated systematically by study of the morphology, linear viscoelastic behavior, and thermal and mechanical properties of the blends. The results show that there is good agreement between the results obtained by rheological measurement and morphological analysis. The rheological test shows that the melt elasticity and melt strength of the blends increase with the addition of SEBS‐g‐MAH. The Cole‐Cole plots and van Gurp‐Palmen plots confirm the compatibilizing effect of SEBS‐g‐MAH. However, the Palierne model fails to predict the linear viscoelastic properties of the blends. The morphology observation shows that all blends exhibit a droplet‐matrix morphology. In addition, the SEEPS particle size in the (R‐PET)/SEEPS blends is significantly decreased and dispersed uniformly by the addition of SEBS‐g‐MAH. Differential scanning calorimeter analysis shows that the crystallization behavior of R‐PET is restricted by the incorporation of SEEPS, whereas the addition of SEBS‐g‐MAH improves the crystallization behavior of R‐PET compared with that of uncompatibilized (R‐PET)/SEEPS blends. The Charpy impact strength of the blends shows the highest value at SEBS‐g‐MAH content of 10%, which is about 210% higher than that of pure R‐PET. J. VINYL ADDIT. TECHNOL., 22:342–349, 2016. © 2014 Society of Plastics Engineers