Uses of electron‐beam irradiation to prepare pH‐ and temperature‐sensitive hydrogels from reactive poly(vinyl alcohol) grafts

Thermosensitive poly(vinyl alcohol)‐graft‐(maleic anhydride), PVA‐MA, and poly(vinyl alcohol)‐graft‐(N‐isopropylacrylamide maleic anhydride) (PVA‐MA‐NIPAAm) copolymers containing carboxyl groups were prepared using electron beam irradiation at dose 80 kGy. The swelling ratios of the cross‐linked gels were measured at various temperatures. The LCST values were measured using DSC technique. The temperature dependence of the swelling ratios of the cross‐linked copolymers and terpolymers were measured at different temperatures. The swelling ratios of copolymers increased with increasing temperature up to 25–38°C, then decreased. The swelling behavior of both copolymers and terpolymers was referred to formation of hydrogen bonds between amide group of NIPAAm moieties and carboxyl group in MA moieties and to hydrophobic interaction due to methyl groups of NIPAAm. The swelling behaviors of these gels were analyzed in buffer solution at various pH. Swelling ratios of all gels were relatively high and they showed reasonable sensitive to pH. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermal characterization of n‐alkyl maleate‐styrene‐allyl propionate terpolymers

Thermal characterization of maleic anhydride‐styrene‐allyl propionate (MA‐St‐AP) terpolymer and its ester derivatives named as n‐alkyl maleate and shown as nPr MA‐St‐AP, nBu MA‐St‐AP, nPn MA‐St‐AP, and nBz MA‐St‐AP was carried out. The thermal characterization was performed using thermal analysis techniques such as TGA, DTA, DSC, and TMA. Different results were observed between the original terpolymer and its ester derivatives. Thermal stabilities of the terpolymer and its ester derivatives were compared by using various measurements plotted as TGA, DTA, DSC, and TMA curves. The increase in the alcohols' carbon numbers added to the original terpolymer results in ester derivatives with different thermal stability behavior. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 600–604, 2007     

Synthesis and antitumor activity of poly(3,4‐dihydro‐2H‐pyran‐co‐maleic anhydride‐co‐vinyl acetate)

The radical‐initiated terpolymerization of 3,4‐dihydro‐2H‐pyran (DHP), maleic anhydride (MA), and vinyl acetate (VA), which were used as a donor–acceptor–donor system, was carried out in methyl ethyl ketone in the presence of 2,2′‐azobisisobutyronitrile as an initiator at 65°C in a nitrogen atmosphere. The synthesis and characterization of binary and ternary copolymers, some kinetic parameters of terpolymerization, the terpolymer‐composition/thermal‐behavior relationship, and the antitumor activity of the synthesized polymers were examined. The polymerization of the DHP–MA–VA monomer system predominantly proceeded by the alternating terpolymerization mechanism. The in vitro cytotoxicities of poly(3,4‐dihydro‐2H‐pyran‐alt‐maleic anhydride) [poly(DHP‐alt‐MA)] and poly(3,4‐dihydro‐2H‐pyran‐co‐maleic anhydride‐co‐vinyl acetate) [poly(DHP‐co‐MA‐co‐VA)] were evaluated with Raji cells (human Burkitt lymphoma cell line). The antitumor activity of the prepared anion‐active poly(DHP‐alt‐MA) and poly(DHP‐co‐MA‐co‐VA) polymers were studied with methyl–thiazol–tetrazolium testing, and the 50% cytotoxic dose was calculated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2352–2359, 2005     

Copolymerization of N‐substituted maleimide with alkyl acrylate and its industrial applications

A series of new copolymers with desired thermal stability and mechanical properties for applications in leather industry were synthesized from various substituted maleimides and alkyl acrylates. Polymerization was carried out by a free‐radical polymerization using benzoyl peroxide (BPO) as initiator. The monomers and polymers synthesized were characterized by elemental analysis, IR, and nuclear magnetic resonance (NMR). Interestingly, these polymers were soluble in common organic solvents. Copolymer composition and reactivity ratios were determined by ¹H‐NMR spectra. The molecular weights of the polymers were determined by gel permeation chromatography. The homo‐ and copolymer of maleimide showed single‐stage decomposition (ranging from 300–580°C). The initial decomposition temperatures of poly[N‐(phenyl)maleimide] [poly(PM)], poly[N‐4‐(methylphenyl)maleimide] [poly(MPM)] and poly[N‐3‐(chlorophenyl)maleimide] [poly(CPM)] were higher compared to those of the copolymers. Heat‐resistant adhesives such as blends of epoxy resin with phenyl‐substituted maleimide‐co‐glycidyl methacrylate copolymers with improved adhesion property were developed. Different adhesive formulations of these copolymaleimides were prepared by curing with diethanolamine at two different temperatures (30°C and 60°C). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1870–1879, 2001     

Synthesis,characterization, and antitumor activity of poly(maleic anhydride‐co‐vinyl acetate‐co‐acrylic acid)

The ternary copolymerization of maleic anhydride (MA), vinyl acetate (VA), and acrylic acid (AA) [P(MA‐co‐VA‐co‐AA)], which is considered to be an acceptor–donor–acceptor system, was carried out in 1,4‐dioxane with benzoyl peroxide as an initiator at 70°C under a nitrogen atmosphere. Constants of complex formation for the monomer systems in the study were determined by UV–visible (hydrogen‐bonding complex) and ¹H‐NMR (charge transfer complex) methods, respectively. The results show that polymerization of the P(MA‐co‐VA‐co‐AA) system proceeds by an alternating terpolymerization mechanism. It is shown that the synthesized copolymers have typical polyelectrolyte behavior, ability for reversible hydrolysis–anhydrization reactions, and semicrystalline structures. In these cases, including radical polymerization, and formation of semicrystalline structures, the hydrogen‐bonding effect plays a significant role. The in vitro cytotoxicities of the synthesized terpolymer and alternating copolymer were evaluated using Raji cells (human Burkitt lymphoma cell line). The antitumor activities of prepared anion‐active copolymers were studied using methyl–thiazol–tetrazolium colorimetric assay and 50% of the cytotoxic dose of each copolymer and terpolymer were calculated. Hydrolyzed P(MA‐co‐VA‐co‐AA) and P(MA‐alt‐AA) copolymers have sufficiently high antitumor activity, which depends on the amount of hydrogen‐bonding carboxylic groups and their regular distribution in the side chain of functional macromolecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3425–3432, 2006     

Synthesis and characterization of anionic graft copolymers containing poly(ethylene oxide) grafts

Graft copolymers containing poly(ethylene oxide) side chain attached to maleic anhydride‐alt‐vinyl methyl ether (MA‐VME) copolymer were prepared by coupling MA‐VME and poly(ethylene glycol) monomethyl ether (MPEG) by esterification in DMF at 90°C. MPEG and dodecyl alcohol (DA) were grafted onto MA‐VME copolymer in o‐xylene at 140°C in the presence of p‐toluene sulfonic acid as catalyst. The molecular weights of MPEG were found to influence the rate of the grafting reaction and the final degree of conversion. The graft copolymers were characterized by IR, GPC, and ¹H‐NMR. DSC was used to examine thermal properties of the graft copolymers. The analysis indicates that grafts have phase‐separated morphology with the backbone and the MPEG grafts forming separate phases. The properties in aqueous solutions of these grafts were studied with respect to aggregation behavior and viscometric properties. In aqueous solution, the polymers exhibited polyelectrolyte behavior (i.e., a dramatic increase of the viscosity upon neutralization). Graft copolymers with DA have lower viscosities. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1138–1148, 2002     

Synthesis and application of 2‐acrylamido‐2‐methyl propane sulfonic acid/acrylamide/N,N‐dimethyl acrylamide/maleic anhydride as a fluid loss control additive in oil well cementing

Using 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS), acrylamide (AM), N,N‐dimethyl acrylamide (NNDMA), and maleic anhydride (MA), a new dispersive type fluid loss control additive (FLCA) AMPS/AM/NNDMA/MA (PANM) was synthesized by free radical aqueous solution copolymerization, and the new FLCA could be used without dispersant existing in the cement. The optimal PANM (OPANM) was obtained under the optimum reaction conditions: mole ratio of AMPS/AM/NNDMA/MA = 4/2.5/2.5/1, monomer concentration = 32.5%, amount of (by weight of monomer) ammonium persulfate/sodium bisulfate = 1.0%, pH value = 4, and temperature = 40°C. The synthesized copolymer OPANM was identified by FTIR analysis. The evaluation results show the OPANM has excellent dispersing power, fluid loss control ability, thermal resistant, and salt tolerant ability. The OPANM was even stable when the temperature was below 300°C proved by TG analysis. The thickening time of the slurry containing the synthesized additive reduces as the temperature increases. The copolymer OPANM is expected to be an excellent FLCA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH₄OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO₂. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO₂ particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007     

Complex-radical copolymerization of <Emphasis Type="Italic">N-</Emphasis>vinyl pyrrolidone with isostructural analogs of maleic anhydride

Radical copolymerizations of N-vinyl-2-pyrrolidone (VP) with isostructural analogs of maleic anhydride (MA), such as citraconic anhydride (CA) and N-substituted maleimides [maleimide (MI), N-ethylmaleimide (EMI) and N-phenylmaleimide (PhMI)] were studied. Compositions of copolymers synthesized in a wide range of monomer feed ratios were determined by alkali titration (for anhydride copolymers), FTIR and ¹H NMR spectroscopy using 1495 and 630 cm^-1 (for VP-MI), 1289 and 1225 cm^-1 (for VP-EMI) and 1050 and 3067 cm^-1 (for VP-PhMI) analytical bands and integral areas of CH₂ (pyrrolidone ring) and CH (MI), CH₃ (EMI) and CH= (benzene ring in PhMI) groups, respectively. Electron-donor VP monomer was found to have substantially different reactivities in the radical copolymerization with MA, CA and N-substituted (H, C₂H₅ and phenyl) malemides as electron-acceptor comonomers. Effects of H-bonding and N→O=C coordination on the monomer reactivity ratios were evaluated. Tendency to alternation of the monomer pairs increases in the order of VP–MA > VP–CA > VP-MI > VP-PhMI > VP-EMI. Structure-thermal property-relationship for the synthesized copolymers was also studied.     

Complex-radical copolymerization of <Emphasis Type="Italic">N-</Emphasis>vinyl pyrrolidone with isostructural analogs of maleic anhydride

Radical copolymerizations of N-vinyl-2-pyrrolidone (VP) with isostructural analogs of maleic anhydride (MA), such as citraconic anhydride (CA) and N-substituted maleimides [maleimide (MI), N-ethylmaleimide (EMI) and N-phenylmaleimide (PhMI)] were studied. Compositions of copolymers synthesized in a wide range of monomer feed ratios were determined by alkali titration (for anhydride copolymers), FTIR and ¹H NMR spectroscopy using 1495 and 630 cm^-1 (for VP-MI), 1289 and 1225 cm^-1 (for VP-EMI) and 1050 and 3067 cm^-1 (for VP-PhMI) analytical bands and integral areas of CH₂ (pyrrolidone ring) and CH (MI), CH₃ (EMI) and CH= (benzene ring in PhMI) groups, respectively. Electron-donor VP monomer was found to have substantially different reactivities in the radical copolymerization with MA, CA and N-substituted (H, C₂H₅ and phenyl) malemides as electron-acceptor comonomers. Effects of H-bonding and N→O=C coordination on the monomer reactivity ratios were evaluated. Tendency to alternation of the monomer pairs increases in the order of VP–MA > VP–CA > VP-MI > VP-PhMI > VP-EMI. Structure-thermal property-relationship for the synthesized copolymers was also studied.     

Thermosetting allyl resins derived from soybean fatty acids

A novel class of thermosetting resins based on allylated and transesterified epoxidized soybean oil (AE‐ESBO) curable by radical mechanism was developed. The AE‐ESBO was prepared from ESBO by oxirane ring‐opening and then transesterification with allyl alcohol. A family of rubbery to glassy resins was prepared by radical copolymerization of AE‐ESBO with different concentrations of maleic anhydride (MA). Glass transition temperatures (T_g) of these resins ranged from below room temperature to about 130°C based on the amount of MA. In spite of the presence of anhydride groups, water absorption was low <2% even when maleic anhydride was 30% of total weight. Low sol content after extraction and low swelling in toluene indicated high crosslinking density. Tensile moduli of these resins were up to 1.4 GPa and tensile strengths up to 37 MPa. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Polymerization of N-(tert-butyldimethylsilyloxy)maleimide and applications of the polymers as resist materials

A new silicon-containing maleimide monomer, N-(tert-butyldimethylsilyloxy)-maleimide (SiOMI) has been synthesized. SiOMI was radically copolymerized with styrene derivatives (XSt) to obtain alternating copolymers, P(SiOMI/XSt), in high conversions. The copolymers have high glass transition temperatures above 190°C, and the tert-butyldimethylsilyloxy groups are thermally stable up to 300°C. The SiOMI units in the copolymers were converted into N-hydroxymaleimide (HOMI) units by acidolytic deprotection of the tert-butyldimethylsilyloxy protecting groups. The facile deprotection of the side-chain tert-butyldimethylsilyloxy groups from the protected copolymers provided a significant change in solubility of the polymers due to the large polarity change. Submicron positive-tone images were obtained from the copolymers containing an onium salt as a photoacid generator by irradiation with electron beam and development with alkaline solutions. The polymer films also showed very high oxygen plasma etch resistance compared with novolac resins. The silicon-containing maleimide polymers were found to have required properties, such as good alkaline solubility after deprotection, superior adhesion, low optical density, high thermal stability with high T_g, and high plasma etch resistance for applications as deep ultraviolet and electron beam resist materials. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2507–2516, 1997     

Synthesis and characterization of poly(methyl methacrylate‐co‐maleic anhydride) copolymers and its potential as a compatibilizer for amorphous polyamide blends

Poly(methyl methacrylate‐co‐maleic anhydride) copolymers (MMA‐MA) have been synthesized by solution method, using toluene as solvent and benzoyl peroxide as initiator. The MMA‐MA copolymers were characterized by size exclusion chromatography, Fourier transforms infrared spectroscopy (FTIR), and titration. It was found that the modified polymerization procedure used in this work was more effective in controlling the molecular weight when adding different amounts of maleic anhydride (MA) than procedures previously used. In spite of the significant difference in reactivity ratios between MMA and MA, up to 50% of the MA added to the reactor was incorporated into the copolymer. The evidences for reactions of the MA groups of the MMA‐MA copolymer with the amine end groups of the amorphous polyamide (aPA) during melt blending was obtained by rheological measurements. In this work, the molecular weight and the content of MA reactive functional groups in the MMA‐MA copolymer were varied independently and its effects on the interaction with aPA were studied. It was observed that a compromise between molecular weight and the level of reactive functional group of the compatibilizer should be sought to improve the compatibilization of the polymer systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Kinetics and simulation of the imidization of poly(styrene‐co‐maleic anhydride) with amines

The imidization of poly(styrene‐co‐maleic anhydride) with amines may improve some of its end‐use properties. The objective of this study was to examine the mechanism and kinetics with aniline (ANL) as an amine of the preparation of poly(styrene‐co‐N‐phenyl maleimide). The reaction was carried out in a tetrahydrofuran solution at 25–55°C and in an ethylbenzene solution at 85–120°C. The extent of the reaction was determined by conductance titration, a new and simple method. Two consecutive reactions were involved in the imidization: ring opening to produce an acido‐amide group and ring closing to form a corresponding imide group. The imidization rate was greatly influenced by the reaction temperature and the molar ratio of ANL to the anhydride. A model for the imidization kinetics over a wide range of reaction temperatures and concentration ranges was developed and validated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2744–2749, 2006     

Effect of compatibilization on the properties of HIPS/PA1010 blends

Blends consisting of high‐impact polystyrene (HIPS) as the matrix and polyamide 1010 (PA1010) as the dispersed phase were prepared by mixing. The grafting copolymers of HIPS and maleic anhydride (MA), the compatibilizer precursors of the blends, were synthesized. The contents of the MA in the grafting copolymers are 4.7 wt % and 1.6 wt %, and were assigned as HAM and LMA, respectively. Different blend morphologies were observed by scanning electron microscopy (SEM); the domain size of the PA1010 dispersed phase in the HIPS matrix of compatibilized blends decreased comparing with that of uncompatibilized blends. For the blend with 25 wt % HIPS‐g‐MA component, the T_c of PA1010 shifts towards lower temperature, from 178 to 83°C. It is found that HIPS‐g‐MA used as the third component has profound effect on the mechanical properties of the resulting blends. This behavior has been attributed to the chemical reaction taking place in situ during the mixing between the two components of PA1010 and HIPS‐g‐MA. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 799–806, 2000     

Direct polymer reaction of poly(styrene‐co‐maleic anhydride): Polymeric imidization

Using direct polymer reaction of poly(styrene‐co‐maleic anhydride) (SMA), a synthesis of copolymer of styrene and N‐aryl succinimide (SMI) has been investigated. SMI copolymers were synthesized from SMA copolymers by a concerted two‐step reaction, which consisted of the condensation reaction (step 1) of SMA with aromatic amine to prepare a precursor, succinamic acid, for imide formation and the cyclodehydration reaction (step 2) of succinamic acid. In this article, the application of Searle's preparation method of N‐aryl or N‐alkyl maleimide to the direct polymer reaction for SMI was attempted. Compared with synthesis of monomeric imides, the imide formation in polymeric condition appeared to be a little more sensitive to the reaction condition. The optimum condition for maximum conversion was examined in terms of time, temperature, and the amount of reactants. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1187–1196, 1999     

Synthesis of a novel series of propargyloxyphenyl maleimides and their characterization as thermal‐resistance resins

Novel thermosetting monomers possessing both maleimide and propargyl groups were first designed and synthesized. The monomers included N‐(2‐propargyloxyphenyl) maleimide (2‐PPM), N‐(3‐propargyloxyphenyl) maleimide (3‐PPM), and N‐(4‐propargyloxyphenyl) maleimide (4‐PPM), and their structures were confirmed with Fourier transform infrared (FTIR) spectroscopy, ¹H‐NMR, and elemental analysis. The cure behaviors of these monomers were characterized with differential scanning calorimetry and FTIR spectroscopy, and the results indicated that the monomers had a broader processing window than normal bismaleimide (BMI) resins. The thermal properties of the cured monomers were characterized with thermogravimetric analysis and dynamic mechanical analysis. The 5% mass loss temperatures of the cured monomers were high (ca. 400°C), and the glass‐transition temperatures of cured 2‐PPM, 3‐PPM, and 4‐PPM were 386, 373, and 387°C, respectively, which were much higher than those of typical commercial blended BMI resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of new hydrogels on the basis of water‐soluble maleic anhydride copolymers with γ‐aminopropyltriethoxysilane

This work describes the synthesis and macromolecular reactions of maleic anhydride (MA)–acrylic acid (AA) binary reactive copolymers with γ‐aminopropyltriethoxysilane (APTS) as a polyfunctional crosslinker. Copolymers with a given composition of MA–AA (47.17–52.83 wt %) were synthesized by radical binary copolymerization with benzoyl peroxide as an initiator in p‐dioxane at 70°C in nitrogen atmosphere and initial monomer ratio of 1 : 1. It is shown that the network structure is formed in MA–AA/APTS in water by intermolecular reaction between the anhydride unit and the amine group, as well as between the etoxysilyl fragment and free carboxyl groups of the acrylic acid and maleic anhydride unit. Swelling parameters such as beginning time of hydrogel formation, initial rate of swelling, swelling rate constant, equilibrium swelling, and equilibrium water content were determined for copolymer/APTS/water systems with various copolymer/crosslinker ratios. Formation of a hyperbranched network structure through the fragmentation of side‐chain reactive groups in the studied systems was confirmed by FTIR, TGA, and DSC methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4009–4015, 2003     

Toughening of polyamide 6 with a maleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer

Maleic anhydride functionalized acrylonitrile–butadiene–styrene (ABS‐g‐MA) copolymers were prepared via an emulsion polymerization process. The ABS‐g‐MA copolymers were used to toughen polyamide 6 (PA‐6). Fourier transform infrared results show that the maleic anhydride (MA) grafted onto the polybutadiene phase of acrylonitrile–butadiene–styrene (ABS). Rheological testing identified chemical reactions between PA‐6 and ABS‐g‐MA. Transmission electron microscopy and scanning electron microscopy displayed the compatibilization reactions between MA of ABS‐g‐MA and the amine and/or amide groups of PA‐6 chain ends, which improved the disperse morphology of the ABS‐g‐MA copolymers in the PA‐6 matrix. The blends compatibilized with ABS‐g‐MA exhibited notched impact strengths of more than 900 J/m. A 1 wt % concentration of MA in ABS‐g‐MA appeared sufficient to improve the impact properties and decreased the brittle–ductile transition temperature from 50 to 10°C. Scanning electron microscopy results show that the shear yielding of the PA‐6 matrix was the major toughening mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of a branched photosensitive copolymer and its application for negative‐type photoresists

Novel branched copolymers, poly(styrene‐alt‐maleic anhydride) (BPSMA), were synthesized through mercapto chain‐transfer polymerization with styrene, maleic anhydride (MA), and 4‐vinyl benzyl thiol (VBT). Then, the hydroxyl of hydroxyethyl methacrylate was reacted with MA to synthesize branched photosensitive copolymers, p‐BPSMAs. Fourier transform IR spectroscopy and ¹H‐NMR indicated that the synthesis was successful. Gel permeation chromatography indicated that the molecular weight decreased with increasing content of VBT. The thermal properties were characterized by thermogravimetric analysis; the results show that the thermal decomposition temperature of the BPSMAs was greatly enhanced. Real‐time IR was used to evaluate the UV‐curable kinetics of the p‐BPSMAs; the results show that the p‐BPSMAs could rapidly photopolymerize under UV irradiation in the presence of photoinitiators. Moreover, the photoresist based on the p‐BPSMAs exhibited improved photosensitivity when the VBT content increased, and the photoresist with 12 mol % VBT content had a low value of the dose that retained 50% of the original film thickness (10 mJ/cm²), and a 50‐μm resolution could be achieved compared to a linear photoresist. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42838.