The aminolysis of styrene–maleic anhydride copolymers for a new modifier used in urea-formaldehyde resins

Styrene (St) and maleic anhydride (MA) alternating copolymers with different molecular weights (MW) were synthesized via radical copolymerization. The copolymers were subsequently transferred into water-soluble maleic amic acid derivatives (SMAA) via the aminolysis of anhydride groups using (NH₄)₂CO₃ as the ammonia sources. The synthesized polymers were applied as a new kind of macromolecular modifier and added into the reaction system during the synthesis of urea-formaldehyde (UF) resins via the traditional alkaline–acidic–alkaline three-step process. The UF resins modified with SMAA were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), ¹³C nuclear magnetic resonance (¹³C-NMR) spectroscopy, and thermal gravimetric analysis (TGA). All the results confirmed the successful incorporation of SMAA chains into the crosslinking network of the UF resins. The modified UF resins were further employed as wood adhesives and the effect of synthesis parameters on their performance was investigated. Meanwhile, the influence of SMAA molecular weight (MW) on the properties of the modified UF resins was also studied. When the UF resins were synthesized with a low molar ratio of formaldehyde/urea (F/U) and a predetermined amount of SMAA added into the reaction system at the second step, plywood bonded using these modified UF resins showed much improved bonding strength (BS) and depressed formaldehyde emission. Moreover, the as-modified UF resins showed good storage characteristics.     

Decreasing the formaldehyde emission in urea‐formaldehyde using modified starch by strongly acid process

The incorporation of the modified starch (MS) in urea‐formaldehyde resins at different stage of the synthesis was studied in this article. The synthesized resins were characterized by Fourier transform infrared spectroscopy, indicating that the ester bond can be introduced into the UF structure after the addition of MS. The curing reactions were examined with differential scanning calorimetry and it reveals that curing temperature of UF resin are slightly shifted to higher temperatures. To study the bonding strength and formaldehyde emission of the bonded plywood, the addition method and amount of MS are systematically investigated. The performance of the UF resins is remarkably improved by the addition of MS around 15% (weight percentage of the total resin) in the second stage. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40202.     

13C‐NMR, 13C‐13C gCOSY,and ESI‐MS characterization of ether‐bridged condensation products in N,N′‐dimethylurea‐formaldehyde systems

The reaction of urea with formaldehyde is the basis for the production of urea‐formaldehyde (UF) resins which are widely applied in the wood industry. The presence of ether‐bridged condensation products in the UF resin reaction system is an open question in the literature. It is addressed in the present work. The N,N′‐dimethylurea‐formaldehyde model system was studied since it is chemically similar to the UF resin reaction system but allows for a simple elucidation of all reaction products. It was analyzed by ¹³C‐NMR spectroscopy and ESI‐MS. In corresponding NMR and MS spectra, peaks due to methoxymethylenebis(dimethyl)urea and its hemiformal were observed. ¹³C‐¹³C gCOSY analysis was conducted using labeled ¹³C‐formaldehyde. The correlation spectra showed evidence for an ether‐bridged compound and mass spectra exhibited peaks agreeing with labeled methoxymethylenebis(dimethyl)urea and its hemiformal. Methoxymethylenebis(dimethyl)urea was characterized in N,N′‐dimethylurea‐formaldehyde systems in acidic and slightly basic media. As urea is very similar to N,N′‐dimethylurea, the results of this work strengthen the assumption that ether‐bridged condensation products are likely to form in UF resins. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Influence of acrylamide copolymerization of urea–formaldehyde resin adhesives to their chemical structure and performance

To lower the formaldehyde emission of wood‐based composite panels bonded with urea–formaldehyde (UF) resin adhesive, this study investigated the influence of acrylamide copolymerization of UF resin adhesives to their chemical structure and performance such as formaldehyde emission, adhesion strength, and mechanical properties of plywood. The acrylamide‐copolymerized UF resin adhesives dramatically reduced the formaldehyde emission of plywood. The ¹³C‐NMR spectra indicated that the acrylamide has been copolymerized by reacting with either methylene glycol remained or methylol group of UF resin, which subsequently contributed in lowering the formaldehyde emission. In addition, an optimum level for the acrylamide for the copolymerization of UF resin adhesives was determined as 1%, when the formaldehyde emission and adhesion strength of plywood were taken into consideration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The effect of soda bagasse lignin modified by ionic liquids on properties of the urea–formaldehyde resin as a wood adhesive

The aim of this research was to investigate the influence of lignin modified by ionic liquids on physical and mechanical properties of plywood panels bonded with the urea–formaldehyde (UF) resin. For this purpose, soda bagasse lignin was modified by the 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) ionic liquid and then the various contents of unmodified and modified lignins (10, 15, and 20%) were added at pH=7 instead of second urea during the UF resin synthesis. The physicochemical properties of the prepared resins as well as the water absorption, shear strength, and formaldehyde emission of the plywood panels made with these adhesives were measured according to standard methods. According to Fourier Transform Infrared (FTIR) Spectrometry, by treatment of lignin, the C=O, C–C, and C–H bonds decrease while the content of the C–N bond dramatically increases. Based on the finding of this research, the performance of soda bagasse lignin in UF resins dramatically improves by modification by ILs; as the resins with modified lignin yielded lower formaldehyde emission and water absorption when compared to those made from unmodified lignin and commercial UF adhesives, respectively. The shear strength as well as wood failure percentages are lower for the panels produced with modified lignin than for the panels produced with UF resins alone.     

Melamine‐bridged alkyl resorcinol modified urea–formaldehyde resin for bonding hardwood plywood

A powdery product was obtained by the reaction of methylolated melamine with alkyl resorcinols to form melamine‐bridged alkyl resorcinols (MARs). The effects of the addition of this powder on the bonding strength and formaldehyde emission of urea–formaldehyde (UF) resins were investigated. Three types of UF resins with a formaldehyde/urea molar ratio of 1.3 synthesized by condensation at pH 1.0 (UF‐1.0), pH 4.5 (UF‐4.5), and pH 5.0 (UF‐5.0) were fabricated. The addition of MAR to UF‐4.5 and UF‐5.0 for bonding hardwood plywood enhanced the bonding strength and reduced formaldehyde emission. For UF‐1.0, the addition of MAR adversely affected the bonding strength. However, the UF‐1.0 resin yielded the lowest formaldehyde emission of all of the UF resins in the study. The effects of the MAR addition were related to the molecular structures of the UF resins. UF‐1.0 contained a large amount of free urea, a considerable number of urons, and a highly methylene‐linked, ring‐structured higher molecular weight fraction and had a smaller number of methylol groups. Therefore, the addition of MAR was considered to cause a shortage of the methylol groups, which in turn, led to incomplete resin curing. In contrast to UF‐1.0, UF‐5.0 contained a smaller amount of free urea and a linearly structured higher molecular weight fraction and had a larger number of methylol groups. In this case, MAR was considered to effectively react with the methylol groups to develop a three‐dimensional crosslinked polymer network to enhance the bonding strength and suppress the generation of free formaldehyde to reduce formaldehyde emission. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Hydrolyzed soy protein isolates modified urea–formaldehyde resins as adhesives and its biodegradability

The hydrolytes soy protein isolates (HSPI)-modified urea–formaldehyde (UF) resins were synthesized via copolymerization process. The best bonding strength is 1.50 MPa and improves 51.5% compared with pure UF. In addition, the formaldehyde emission decreased. The effect of (HSPI) on the biodegradable (UF) resins was investigated. Biodegradation was evaluated by composting under controlled conditions in accordance with ISO 14855. The faster degradation rate was obtained when lower hydrolysis degree of HSPI was added into the system. Characterization of the resulting samples was performed by attenuated total reflection Fourier transform infrared spectroscopy, thermo-gravimetric analysis, XRD, scanning electron microscopy, and AFM. The results showed that no evidence of biodegradation was found for UF resins. The UF modified with lower hydrolysis degree of hydrolytes soy protein isolates (HSPI) resulted in a faster degradation rate. The HSPI in the network of modified UF degraded first, which resulted in the broken of the network of HSPI-modified UF resins. The thermal stability of degraded resins was found to be enhanced as the mineralization time increased. Not only the surface of the sample was degraded, but also the crystalline regions of the samples were also decomposed. The degradation on the modified UF surface occurs mainly via the formation of holes. The roughness of the degraded surfaces of modified UF resins increases with the hydrolysis degree of HSPI decreases. The presence of HSPI has driven the degradation of urea–formaldehyde. The modified resins used as adhesives in biodegradable seedling container can be seen as a controlled release source of nitrogen fertilizer.     

尤戎(Uron)树脂及其用法对脲醛树脂性能的影响

以不同工艺制备了三种含尤戎结构的脲醛树脂(Uron树脂),通过其与普通脲醛树脂的混合制得多种混合脲醛树脂。研究了Uron树脂及其使用方法对降低脲醛树脂胶粘剂游离甲醛含量及胶接胶合板甲醛释放量的作用与效果。结果表明:1)三种不同摩尔比的Uron树脂对脲醛树脂游离甲醛含量及胶接胶合板甲醛释放量都有明显的降低作用,游离甲醛含量最多可降低43％,甲醛释放量最多可降低61％;2)Uron树脂的添加量在10％-20％时对胶合强度的提高有利,强度最大可提高29％;3)低摩尔比Uron树脂对脲醛树脂的改性效果优于高摩尔比Uron树脂。     

Renewable polyol‐based polycarbamates and polycarbamate–formaldehyde thermosetting resins

Several polycarbamates and polycarbamate–formaldehyde (CF) resins were synthesized, and their properties were investigated aiming at developing of useful thermosetting polymer materials from simple polyols including those derived from renewable resources. Polycarbamates synthesized from polyols using two‐step laboratory routes showed good storage stabilities making them suitable as large volume industrial chemicals. Furthermore, syntheses and ¹³C‐NMR studies of CF resins showed the formation of oligomeric resins having hydroxymethyl and methylene groups with thermosetting curing properties that are similar to those of current urea–formaldehyde (UF) resins. Dynamic mechanical analysis studies showed somewhat slower curing rates for CF resins compared to UF resins. Bonding of particleboard and internal bond and free formaldehyde content measurements indicated high‐bond strength values and very low‐formaldehyde emission potentials for CF resins. The higher functionalities of CF resins appear to be the basis of good performances. Further investigations on scalable synthesis methods for polycarbamates and on the expansion of CF resins' bonding capabilities would need to be investigated in the future. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of hydrolysis degree of soy protein isolate on the structure and performance of hydrolyzed soy protein isolate/urea/formaldehyde copolymer resin

The hydrolyzed soy protein isolate (HSPI) with different hydrolysis degree was applied to modify urea‐formaldehyde resins (UF) via copolymerization process. The properties of HSPI were characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) and TGA. The results show that HSPI with different hydrolysis degree is obtained. ¹H NMR and ATR‐FTIR spectra indicate that HSPI with different hydrolysis degree can incorporate into the structure of cured and uncured UF. The UF modified with higher hydrolysis degree of HSPI possess more stable units and contribute to the lower exothermic peak temperature in DSC curves. The bonding strength of HSPI modified UF increases as the hydrolysis degree of HSPI increases at the hot‐press temperature of 120°C and decreases at the hot‐press temperature of 150°C. The best bonding strength is 1.53 MPa at the hot‐press temperature of 135°C and improved 56.12% compared with UF. In addition, the formaldehyde emission is dramatically reduced. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41469.     

13C‐NMR study on the structure of phenol‐urea‐formaldehyde resins prepared by methylolureas and phenol

Phenol‐urea‐formaldehyde (PUF) resins were synthesized by reacting mixture of methylolureas (MMU), phenol, and formaldehyde. The structure of PUF cocondensed resins at different stages of reaction were analyzed by liquid ¹³C nuclear magnetic resonance (NMR) spectroscopy. The liquid ¹³C‐NMR analysis indicated that methylolureas had the dominant content in MMU with the reaction between urea and formaldehyde under the alkaline condition. The PUF cocondensed resins had no free formaldehyde. methylolureas were well incorporated into the cocondensed resins by reacting with phenolic units to form cocondensed methylene bridges. The second formaldehyde influenced the further reaction and the structure of the PUF resins. The resins with the prepared method of PUFB possessed relatively high degree of polymerization and low proportion of unreacted methylol groups. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis,structure, and characterization of glyoxal‐urea‐formaldehyde cocondensed resins

To decrease the formaldehyde emission of urea‐formaldehyde (UF) bonded products at source, monomethylol urea (MMU) was chosen to react with glyoxal (G), a nonvolatile and nontoxic aldehyde, to prepare a novel glyoxal‐urea‐formaldehyde (GUF) cocondensed resin. The GUF resins were synthesized with different MMU/G molar ratios, and the basic properties were tested. The GUF resins were characterized by ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, carbon‐13 nuclear magnetic resonance spectroscopy and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI‐TOF‐MS). The results show that the synthesized GUF resins remain stable for at least 10 days at ambient temperature. Conjugated structures, and large amounts of ? OH, ? NH? , C? N, and C?O groups with different levels of substitution exist in the GUF resin. There are two repeating motives in the MALDI‐TOF‐MS spectrum of the GUF resin, one of 175 ±1 Da and a second one of 161 ± 1 Da. Moreover, the peaks due to the dehydration condensation reaction of MMU also appear in the spectra. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41009.     

Phenol–urea–formaldehyde resin co-polymer synthesis and its influence on Elaeis palm trunk plywood mechanical performance evaluated by 13C NMR and MALDI-TOF mass spectrometry

This study evaluated a new method of producing phenol–urea–formaldehyde (PUF) adhesives formulated differently under actual “in-situ” resin synthesis conditions. This was carried out by co-polymerizing urea formaldehyde (UF) resin with phenol–formaldehyde resin in the core layer of low molecular weight (LMW) phenol–formaldehyde (PF) resin treated Elaeis palm trunk veneers during the gluing process of Elaeis palm plywood. Matrix assisted laser desorption Ionization time of flight (MALDI-TOF) mass spectrometry (MS) illustrated and confirmed a series number of the phenol–urea co-condensates repeating unit in the prepared PUF resins which corroborated well with its mechanical properties (modulus of elasticity and modulus of rupture), bonding quality (dry test and weather boil proof or WBP test) and physical properties. A series of PF, UF and PUF resins oligomers forming repeating units up to 1833 Da were identified. Besides that, the solid state ¹³Carbon nuclear magnetic resonance (NMR) interpretation identified that the signal at 44–45 ppm and 54–55 ppm corresponding to methylene bridges were co-condensated in between phenol and urea in the PUF resin system. The ¹³C NMR investigation showed that the synthesis process of PUF resin contained no free formaldehyde elements. Furthermore, the proportion of urea and methylolureas in the mixture to synthesis PUF resin were sufficient and incorporated well into the formulation by reacting with LMWPF units to form co-condensed methylene bridges. This study showed a new and useful method to synthesize PUF resin during the gluing process of manufactured Elaeis palm plywood which can also enhance the performance of Elaeis palm plywood panels for structural instead of utility grade applications.     

Determination of formaldehyde/urea molar ratio in amino resins by near‐infrared spectroscopy

New processes for synthesis of urea‐formaldehyde (UF) and melamine‐fortified urea‐formaldehyde (mUF) resins have been developed in the last years, motivated by the current concerns about the effects of formaldehyde on human health. All these formulations are quite susceptible to possible operation error, which can significantly influence the characteristics of the final product. The main objective of this work was to implement chemometric techniques for off‐line monitoring of the product's formaldehyde/urea (F/U) molar ratio using near infrared (NIR) spectroscopy. This allows the timely implementation of the necessary corrections in case the product is off‐specification. Calibration models for F/U molar ratio were developed taking into account the most relevant spectral regions for these resins, individually or in combination (7502–6098 cm^?1 and 5000–4246 cm^?1) and using different preprocessing methods. When the appropriate spectral range and preprocessing methods are selected, it is possible to obtain calibration models with high correlation values for these resins. The best preprocessing methods were identified for three cases: UF resin (produced by strongly‐acid process), mUF resin (alkaline‐acid process), and a combined model that involves both UF and mUF resins. It was concluded that significantly better accuracy is obtained when a new model is developed for each particular resin system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Examination of selected synthesis and room‐temperature storage parameters for wood adhesive‐type urea–formaldehyde resins by 13C‐NMR spectroscopy. IV

Typical particleboard wood‐adhesive urea–formaldehyde (UF) resins, synthesized with formaldehyde/first urea (F/U₁) mol ratios of 1.80, 2.10, and 2.40 and the second urea added to an overall F/U ratio of 1.15, in weak alkaline pH, were allowed to stand at room temperature over a period of 50 days. ¹³C‐NMR of time samples taken over the storage period showed gradual migration of hydroxymethyl groups from the polymeric first‐urea components to the monomeric second‐urea components and also an advancing degree of polymerization of resins by forming methylene and methylene ether groups involving the second urea. These phenomena that varied with the F/U₁ mol ratios used in the resin syntheses due to the varying polymer branching structures resulted in the first step of resin synthesis. Varying viscosity decreases and increases of the resins also occurred. Due to these chemical and physical changes, the particleboards that bonded with the sampled resins showed varying bond strength and formaldehyde‐emission values, indicating process optimizations possible to improve bonding and formaldehyde‐emission performances. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1155–1169, 2001     

Influence of nanoclay on urea‐formaldehyde resins for wood adhesives and its model

The addition of small percentages of Na⁺‐montmorillonite (NaMMT) nanoclay appears to improve considerably the performance of thermosetting urea‐formaldehyde (UF) resins used as adhesives for plywood and for wood particleboard. X‐ray diffraction (XRD) studies indicated that NaMMT loses the periodic atomic structure when mixed in small proportions in the acid‐curing environment characteristic of the curing of UF resins. This can be interpreted as becoming exfoliated under such conditions. The partly crystalline structure of the ordered zones of the UF resins is maintained but at a slightly lower level. Differential scanning calorimetry (DSC) indicated that NaMMT has an accelerating effect on the curing of the UF resin. It also appears to lead to a more controlled rate of crosslinking implying a more regular hardened network. The influence of NaMMT addition was particularly noted in plywood by the increase in water resistance of the UF‐bonded panel. In the case of wood particleboard even the dry internal bond strength of the panel, a direct indication of the performance of the resin, improved with small additions of NaMMT. A hypothesis and model of the reasons why such improvement to the performance of UF resins by addition of nanoclay should occur has been presented. This is based on the application of percolation theory to the networking capability of the clay nanoplatelets. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Modification of urea-formaldehyde resin adhesives with blocked isocyanates using sodium bisulfite

Polymeric 4-4 diphenyl methane diisocyanate (pMDI) was blocked with an aqueous sodium bisulfite solution to obtain water-dispersible blocked pMDI (B-pMDI) resin with different HSO₃/–NCO mole ratios for the modification of urea-formaldehyde (UF) resin. Fourier transform infrared (FTIR) spectra of the B-pMDI resin clearly showed that all isocyanate groups of the pMDI resin were successfully blocked by sodium bisulfite. As the HSO₃/–NCO mole ratio increased, the de-blocking temperature of the B-pMDI resin also increased. Two addition levels (1% and 3%) of the B-pMDI resin with different HSO₃/–NCO mole ratios were mixed with UF resins and used as an adhesive for plywood. The gel time of the UF/B-pMDI resins decreased to a minimum at a mole ratio of 0.9 and then increased with the HSO₃/–NCO mole ratio, and was consistent with the peak temperature (Tp). However, as the HSO₃/–NCO mole ratio increased, the viscosity of the modified UF resins by 1% B-pMDI resin addition slightly increased, whereas those of modified resins with 3% B-pMDI resin addition rapidly increased. The adhesion strengths of plywood bonded with the hybrid resins were greater for 1% B-pMDI resin addition than for 3% B-pMDI resin addition. Formaldehyde emission of plywood bonded with the UF/B-pMDI resins significantly decreased up to 34% by the addition of B-pMDI resin at a mole ratio of 1.8. These results suggest that the modification of UF resins by mixing with water-dispersible B-pMDI resin can be a method for improving the water resistance and formaldehyde emission of UF resins for wood-based composites.     

低甲醛释放量人造板用改性脲醛树脂制备及应用研究

为了降低脲醛树脂的游离甲醛含量及其胶接制品的甲醛释放量,本研究在脲醛树脂合成过程中加入改性剂代替部分甲醛,通过尿素-甲醛-改性剂发生共缩聚反应,合成了改性脲醛树脂。研究了改性剂取代甲醛的摩尔比对改性脲醛树脂固化速度、游离甲醛含量的影响,以及在不同的热压条件下,对胶接胶合板的胶合强度和甲醛释放量的影响。研究结果表明,改性剂的加入不仅能有效降低改性脲醛树脂的游离甲醛含量及其胶合板的甲醛释放量,还能提高胶合板的胶合强度和耐水性。     

Hydrolytic stability of cured urea‐formaldehyde resins modified by additives

Urea‐formaldehyde (UF) resins are prone to hydrolysis that results in low‐moisture resistance and subsequent formaldehyde emission from UF resin‐bonded wood panels. This study was conducted to investigate hydrolytic stability of modified UF resins as a way of lowering the formaldehyde emission of cured UF resin. Neat UF resins with three different formaldehyde/urea (F/U) mole ratios (1.4, 1.2, and 1.0) were modified, after resin synthesis, by adding four additives such as sodium hydrosulfite, sodium bisulfite, acrylamide, and polymeric 4,4′‐diphenylmethane diisocyanate (pMDI). All additives were added to UF resins with three different F/U mole ratios before curing the resin. The hydrolytic stability of UF resins was determined by measuring the mass loss and liberated formaldehyde concentration of cured and modified UF resins after acid hydrolysis. Modified UF resins of lower F/U mole ratios of 1.0 and 1.2 showed better hydrolytic stability than the one of higher F/U mole ratio of 1.4, except the modified UF resins with pMDI. The hydrolytic stability of modified UF resins by sulfur compounds (sodium bisulfate and sodium hydrosulfite) decreased with an increase in their level. However, both acrylamide and pMDI were much more effective than two sulfur compounds in terms of hydrolytic stability of modified UF resins. These results indicated that modified UF resin of the F/U mole ratio of 1.2 by adding acrylamide was the most effective in improving the hydrolytic stability of UF resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Examination of selected synthesis and room‐temperature storage parameters for wood adhesive‐type urea–formaldehyde resins by 13C‐NMR spectroscopy. V

The effects of posttreatments of particleboard adhesive‐type urea–formaldehyde resins were studied. The resins were synthesized with formaldehyde/first urea (F/U₁) mol ratios of 1.40, 1.60, 1.80, 2.10, and 2.40 and then the second urea was added to give a final formaldehyde/urea ratio of 1.15 in alkaline pH. The resins were posttreated at 60°C for up to 13.5 h and the 2.5‐h heat‐treated resin samples were stored at room temperature for up to 27 days. Resins sampled during the posttreatments were examined by ¹³C‐NMR and evaluated by bonding particleboards. In the posttreatments, hydroxymethyl groups on the polymeric resin components dissociated to formaldehyde and reacted with the second urea, and methylene and methylene–ether groups were formed from reactions involving the second urea. Methylene–diurea and urea groups bonded to UF polymers were identified. As a result, the viscosity of the resins initially decreased but later increased along with the cloudiness of the resins. Bond‐strength and formaldehyde‐emission values of particleboard varied with posttreatment variables as well as with the F/U₁ mol ratios used in the resin syntheses. The results would be useful in optimizing resin synthesis and handling parameters. Various reaction mechanisms were considered. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1896–1917, 2003