Synthesis of novel polyurethanes containing dioxybenzylidenecyanoacetate,as non‐linear optical chromophores and their properties

Methyl 3,4‐di‐(2′‐hydroxyethoxy)benzylidenecyanoacetate (3) was prepared by hydrolysis of methyl 3,4‐di‐(2′‐vinyloxyethoxy)benzylidenecyanoacetate (2). Diol 3 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate, and 1,6‐hexamethylenediisocyanate to yield polyurethanes 4, 5 and 6 containing the non‐linear optical (NLO) chromophore 3,4‐dioxybenzylidenecyanoacetate. The resulting polyurethanes 4–6 were soluble in common organic solvents such as acetone and DMF. T_g values of the polymers obtained from DSC thermograms were in the range 80–102 °C. Polymers 4–6 showed thermal stability up to 300 °C in TGA thermograms, and electro‐optic coefficients (r₃₃) of the poled polymer films were in the range 10–12 pm V^?1 at 633 nm, which are acceptable for NLO device applications. © 2002 Society of Chemical Industry     

Synthesis and nonlinear optical properties of novel Y‐type polyurethane containing nitrothiazolylazoresorcinoxy groups with highly enhanced thermal stability of second harmonic generation

Novel Y‐type polyurethane 4 containing 4‐(5‐nitro‐2‐thiazolylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which are parts of the polymer main chains, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as N,N‐dimethylformamide and dimethylsulfoxide. It shows thermal stability up to 280 °C as determined from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of about 126 °C. The second harmonic generation (SHG) coefficient (d₃₃) of poled polymer film at 1064 nm fundamental wavelength is 3.78 pm V^?1. Polymer 4 exhibits thermal stability even at 4 °C higher than glass transition temperature, and no significant SHG decay is observed below 130 °C, which is acceptable for NLO device applications. © 2016 Society of Chemical Industry     

Synthesis and nonlinear optical properties of a novel polyurethane containing cyanovinylthiophene with enhanced thermal stability of dipole alignment for electro‐optic applications

Stabilization of electrically induced dipole alignment is one of the important criteria in the development of nonlinear optical (NLO) polymers for electro‐optic device applications. Polyurethanes for NLO applications have attracted attention because of their high thermal stability due to hydrogen bonding. In the work reported here, we designed and synthesized a new type of NLO polyurethane, in which the pendant NLO chromophores are part of the polymer backbone. This mid‐type NLO polymer is expected to have the merits of both main‐chain and side‐chain NLO polymers, namely stable dipole alignment and good solubility. 1‐[3,4‐Di‐(2‐hydroxyethoxy)phenyl]‐2‐(2‐thienyl)ethene was prepared and condensed with 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate to yield a polyurethane. This polyurethane was reacted with tetracyanoethylene to give a novel Y‐type polyurethane (7) containing 1‐(3,4‐dioxyphenyl)‐2‐[5‐(1,2,2‐tricyanovinyl)‐2‐thienyl]ethenes as NLO chromophores, which constitute part of the polymer backbone. Polyurethane 7 is soluble in common organic solvents such as N,N‐dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of ca 162 °C. The second harmonic generation (SHG) coefficient (d₃₃) of a poled polymer film of he polyurethane at 1560 nm fundamental wavelength is ca 1.11 × 10^?18 C. Polymer 7 exhibits an enhanced thermal stability and no significant SHG decay is observed below 150 °C, which is acceptable for NLO device applications. Copyright © 2009 Society of Chemical Industry     

Preparation and electro‐optic properties of novel Y‐type polyimides with highly enhanced thermal stability of second harmonic generation

BACKGROUND: In the development of nonlinear optical (NLO) polymers for electro‐optic device applications, stabilization of electrically induced dipole alignment is one of the important criteria. Polyimides for NLO applications have attracted attention because of their high T_g values and high thermal stability. In this work we designed and synthesized a new type of NLO polyimide, in which the pendant NLO chromophores are parts of the polymer backbone. These mid‐type NLO polymers are expected to have the merits of both main‐chain and side‐chain NLO polymers: stabilization of dipole alignment and good solubility. RESULTS: 3,4‐Bis‐(3,4‐dicarboxyphenylcarboxyethoxy)‐4′‐nitrostilbene dianhydride was prepared and reacted with the corresponding aromatic diamine to yield unprecedented Y‐type polyimides containing 3,4‐dioxynitrostilbenyl groups as NLO chromophores, which constituted parts of the polymer backbones. The resulting polyimides are soluble in polar solvents such as dimethylformamide and dimethylsulfoxide. These polymers showed a thermal stability up to 320 °C in thermogravimetric thermograms with T_g values obtained from differential scanning calorimetry thermograms in the range 143–164 °C. The second harmonic generation (SHG) coefficients (d₃₃) of poled polymer films at the 1064 nm^?1 fundamental wavelength were around 9.45 × 10^?18 C. CONCLUSION: The dipole alignment exhibited exceptionally high thermal stability even at 30 °C higher than T_g. There was no SHG decay below 180–190 °C because of the partial main‐chain character of the polymer structure, which is acceptable for NLO device applications. Copyright © 2007 Society of Chemical Industry     

Synthesis of novel poly(vinyl ether)s containing the oxybenzylidenemalononitrile group as a nonlinear optical chromophore,and their electro‐optic properties

2,4‐Di‐(2′,2′‐dicyanovinyl)‐1‐(2′‐vinyloxyethoxy)benzene and 2,4‐di‐(2′‐carbomethoxy‐2′‐cyanovinyl)‐1‐(2′‐vinyloxyethoxy)benzene were prepared by condensation of 4‐(2′‐vinyloxyethoxy)isophthaldehyde with malononitrile and methyl cyanoacetate, respectively. The two vinyl monomers were polymerized with boron trifluoride etherate as a cationic initiator to yield poly(vinyl ether)s containing two oxybenzylidenemalononitrile and oxybenzylidenecyanoacetate groups, which are effective chromophores for second‐order nonlinear optical applications. These polymers were soluble in common organic solvents such as acetone and dimethyl sulforide. They showed thermal stabilities up to 300 °C from thermogravimetric analysis (TGA), with differential scanning calorimeter (DSC) thermograms giving T_g values in the range 73–87 °C. The second harmonic generation (SHG) coefficients (d₃₃) of poled polymer films were around 1.8 × 10^?9 esu, and these polymers showed good long‐term thermal stability for 60 days at room temperature, which is acceptable for nonlinear optical (NLO) device applications. Copyright © 2004 Society of Chemical Industry     

Molecular design,synthesis, and electro‐optic properties of novel Y‐type polyesters with high thermal stability of second harmonic generation

3,4‐Di‐(2′‐hydroxyethoxy)‐4′‐nitrostilbene was prepared and condensed with terephthaloyl chloride, adipoyl chloride, and sebacoyl chloride to yield novel Y‐type polyesters containing NLO‐chromophore dioxynitrostilbenyl groups, which constituted parts of the polymer backbone. Polymers were found soluble in common organic solvents such as acetone and N,N‐dimethylformamide. They showed thermal stability up to 300 °C in thermogravimetric analysis with glass‐transition temperatures obtained from differential scanning calorimetry in the range 110–152 °C. The second harmonic generation (SHG) coefficients (d₃₃) of poled polymer films at a 1064 cm^?1 fundamental wavelength were around 3.51 × 10^?8 esu. The dipole alignment exhibited high thermal stability even at 10 °C higher than the glass‐transition temperature, and there was no SHG decay below 120 °C for one of these polymers due to the partial main‐chain character of polymer structure, which was acceptable for NLO device applications. Copyright © 2005 Society of Chemical Industry     

Synthesis and electro‐optic properties of novel polyurethane containing the nitrophenylazoresorcinoxy group

A novel Y‐type polyurethane (polyurethane 3) containing 4‐(4‐nitrophenylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 3 is soluble in common organic solvents such as acetone and N,N‐dimethylformamide. It shows thermal stability up to 270 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of 102 °C. The second harmonic generation (SHG) coefficient (d₃₃) of the poled polymer film at 1064 nm fundamental wavelength is 2.06 pm V^?1. Polymer 3 exhibits thermal stability up to T_g, and no significant SHG decay is observed below 100 °C, which is acceptable for nonlinear optical device applications. Copyright © 2012 Society of Chemical Industry     

Synthesis and nonlinear optical properties of a novel X‐type polyester containing dicyanovinylnitroresorcinoxy groups with enhanced thermal stability of dipole alignment

A novel X‐type polyester (5) containing 4‐(2′,2′‐dicyanovinyl)‐6‐nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone, was prepared and characterized. Polyester 5 is soluble in common organic solvents such as N,N‐dimethylformamide and acetone. Polyester 5 shows thermal stability up to 300 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of near 108 °C. The second harmonic generation (SHG) coefficient (d₃₃) of poled polymer films at the 1064 nm fundamental wavelength is 2.99 pm V^?1. The dipole alignment exhibits thermal stability even at 7 °C above the glass transition temperature, and no significant SHG decay is observed below 115 °C due to the partial main‐chain character of the polymer structure, which is acceptable for NLO device applications. © 2013 Society of Chemical Industry     

Synthesis and nonlinear optical properties of novel y‐type polyurethanes containing different concentrations of chromophore

A new series of Y‐type polyurethanes containing different concentrations of nonlinear optical (NLO) chromophore with aniline donor and tricyanofurane (TCF) acceptor have been successfully prepared, and characterized by FTIR, UV‐Vis, and ¹H‐NMR spectra. New polyurethanes were synthesized with different chromophore contents by introducing diol N, N‐dihydroxyethylaniline or 4‐[N, N‐(dihydroxyethyl)amino]benzaldehyde. These NLO polyurethanes exhibit good film forming property and high thermal stability up to 281°C. The highest electro‐optic coefficient (r₃₃) of polymers is up to 39 pm V^?1 measured by simple reflection technique at 1310 nm, and the temporal stability of the poling‐induced order at elevated temperature of 80°C was much improved through the introducing of hydrogen bonding interaction in this system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis,structure, and properties of new methacrylic derivatives of naphthalene‐2,3‐diol

The synthesis of a new monomer, 2,3‐(2‐hydroxy‐3‐methacryloyloxypropoxy)naphthalene, and its copolymerization with divinylbenzene is presented. This monomer was obtained from naphthalene‐2,3‐diol in a two‐step synthesis. Copolymers in the form of porous microspheres were prepared by a suspension‐emulsion polymerization method. As pore‐forming diluents, toluene, 1‐decanol, benzyl alcohol, and their mixtures were used. In studies of their porous structure, two methods were used: the adsorption of nitrogen at low temperatures, which provided information about the porous structure of the material in a dry state, and inverse exclusion chromatography, which provided information about the porous structure of the polymer swollen by a good solvent. The obtained results suggest that the porous structures for the dry and swollen polymers were different. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1886–1895, 2006     

Effects of addition orders on the properties of fluorine‐containing copolyimides

A series of fluorine‐containing copolyimides were synthesized by three different orders of addition of monomers. The fluorine‐containing copolyimides were prepared by the reaction of 4,4′‐diaminodiphenylmethane (DDM) with 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), and pyromellitic dianhydride (PMDA). The synthesis reactions of the copoly(amic acid)s (PA) were carried out by three different orders of addition of the monomers with different molar ratios of 6FDA to PMDA. The viscosity of the PA solution obtained by DDM–(6FDA+PMDA), that is, 6FDA and PMDA added simultaneously to DDM in N‐methyl‐2‐pyrrolidinone (NMP), was higher than the other two addition orders (i.e., DDM–6FDA–PMDA and DDM–PMDA–6FDA). The viscosity decreased as the relative amount of 6FDA to PMDA increased. The copolyimides formed by different addition orders but the same 6FDA‐to‐PMDA molar ratios contained different properties, such as dielectric constant, moisture absorption, contact angle, and optical transparency. All of these copolyimides were insoluble in common organic solvents, such as NMP and tetrahydrofuran. Thermogravimetric analysis showed that the onset temperature of 8% weight loss decreased slightly as [6FDA] : [PMDA] increased. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3252–3258, 2000     

Effect of diisocyanates and chain extenders on the physicochemical properties and morphology of multicomponent segmented polyurethanes based on poly(l‐lactide), poly(ethylene glycol) and poly(trimethylene carbonate)

Multicomponent segmented polyurethanes (SPUs) based on poly(ethylene glycol), poly(l ‐lactide) and poly(trimethylene carbonate) as macrodiols, 2,4‐toluene diisocyanate (2,4‐TDI) or 1,6‐hexane diisocyanate (HDI) as diisocyanate, and 1,4‐butanediol (BDO) or 2,2‐bis(hydroxymethyl)propionic acid (DMPA) as chain extenders were synthesized. The molecular, thermal, dynamic mechanical and morphological features of this set of uncrosslinked polyurethanes are characterized using ¹H NMR, gel permeation chromatography, differential scanning calorimetry, dynamic mechanical thermal analysis (DMTA) and atomic force microscopy techniques. The lower reaction rate of HDI in comparison with 2,4‐TDI allows for better control of the SPU compositions, so that the intrinsic properties of each block can be better combined and modulated. HDI‐based SPUs are semi‐crystalline, while those based on 2,4‐TDI are amorphous, affecting the mechanical properties of these polyurethanes. All SPUs are heterogeneous, presenting morphologies of a disperse phase in a matrix which varies with the macrodiol ratios as well as with the nature of the diisocyanate and chain extender (a finer dispersion of the disperse phase is observed for SPUs of HDI and BDO). DMTA results indicate that the phases are complex mixtures of the different blocks with at least one rich in PLLA. The PEG content is shown to be the most important factor influencing the water sorption capability, while the incorporation of hindering carboxylic acid groups by the use of DMPA allows the water uptake of SPUs to be controlled by the solution pH. All SPUs show a significant loss of molar mass in hydrolytic degradation experiments and, in general, the PLLA‐rich SPUs are more susceptible to degradation. © 2015 Society of Chemical Industry     

Synthesis and properties of novel phosphorus‐containing hardener for epoxy resins

A novel phosphorus‐containing curing agent, 2‐(6‐oxid‐6H‐dibenz〈c,e〉〈1,2〉oxa‐phosphorin‐6‐yl) phenol formaldehyde novolac [OD‐PN], was prepared from phenol formaldehyde novolac resin (PN) and a reactive 2‐(6‐oxid‐6H‐dibenz〈c,e〉〈1,2〉oxa‐phosphorin‐6‐yl)chloride (ODC) while ODC was synthesized through reaction between o‐phenylphenol and phosphoryl trichloride. The compound (OD‐PN) was used as a reactive flame‐retardant in o‐cresol formaldehyde novolac epoxy resin (CNE) for electronic application. Owing to the rigid structure of ODC and pendant P group, the resulted phosphorus containing epoxy resin exhibited better flame retardancy, higher glass transition temperature, and thermal stability than the noncyclic P‐containing curing agent or the bromine containing flame‐retardant epoxy resin. UL 94‐VO rating could be achieved with a phosphorus content of as low as 1.21% (comparable to bromine content of 6%) in the cured resin, and no fumes and toxic gas emission were observed. The relationship between the structure and flammability for both phosphorus containing curing agents OD‐PN and TP‐PN (triphenyl phosphate‐phenol formaldehyde novolac reaction product) are also examined. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1636–1644, 2000     

Synthesis of novel T-type nonlinear optical polyester with enhanced thermal stability of second harmonic generation for electro-optic applications

2,5-Di-(2′-hydroxyethoxy)benzylidenemalononitrile (3) was prepared and condensed with terephthaloyl chloride to yield novel T-type polyester (4) containing 2,5-dioxybenzylidenemalononitrile groups as NLO-chromophores, which are parts of the polymer backbones. The resulting polymer 4 was soluble in common organic solvents such as acetone and DMF and showed thermal stability up to 280 °C with T _g of 83 °C. The second harmonic generation (SHG) coefficient (d ₃₃) of poled polymer film at the 1,064 nm fundamental wavelength was around 4.46 × 10⁻⁹ esu. The dipole alignment exhibited high thermal stability even at 10 °C higher than T _g, and there was no SHG decay below 95 °C due to the partial main-chain character of polymer structure, which was acceptable for NLO device applications.     

Atomic force microscopy of cellulose membranes prepared from the N‐methylmorpholine‐N‐oxide/water solvent system

Cellulose membranes were obtained by solutions of cellulose being cast into a mixture of N‐methylmorpholine‐N‐oxide (NMMO) and water under different processing conditions. Atomic force microscopy (AFM) was used to investigate the surface structures of the membranes. The AFM method provided information on both the size and shape of the pores on the surface, as well as the roughness of the skin, through a computerized analysis of AFM micrographs. The results obtained showed that the surface morphologies were intrinsically associated with the permeation properties. For the cellulose membranes, increasing the NMMO concentration and the temperature of the coagulation bath led to higher fluxes and lower bovine serum albumin rejection. These were always correlated with higher values of the roughness parameters and larger pore sizes of the membrane surfaces. When the cellulose concentration of the casting solution was 11 wt %, the membrane showed a nodular structure with interconnected cavity channels between the agglomerated nodules. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3389–3395, 2002     

Synthesis and properties of novel flame‐retardant poly(amide‐imide)s containing phosphine oxide moieties in main chain by microwave irradiation

Eight new flame‐retardant poly(amide‐imide)s with high inherent viscosities containing phosphine oxide moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7, with eight ;aromatic diamine 8a–h by two different methods such as solution and microwave‐assisted polycondensation. Results showed that the microwave‐assisted polycondensation by using a domestic microwave oven proceeded rapidly, compared with solution polycondensation and were completed within about 10–12 min. The resulting poly(amide‐imide)s 9a–h showed high thermal stability and flame‐retardant properties. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties of the PAIs 9a–h were investigated by using thermal gravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), and differential scanning calorimetry (DSC). Char yield measurements at 600°C demonstrated that incorporating phosphine oxide moieties in polymer backbone markedly improves their flame retardancy. All of the earlier polymers were soluble at room temperature in various organic solvents such as NMP, DMF, DMSO, DMAc, and concentrated sulfuric acid. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4263–4269, 2006     

Development of polyurethanes with azo‐type chromophores for second‐order nonlinear optical applications

Active nonlinear optical nitro‐substituted thiazole, benzothiazole, and thiadiazole chromophores were prepared and condensed with tolylene‐2,4‐diisocyanate (TDI) and 4,4′‐methylenedi(phenyl isocyanate) (MDI) to yield a series of polyurethanes. The resulting polyurethanes were characterized with Fourier transform infrared, proton nuclear magnetic resonance, and ultraviolet–visible spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The weight‐average molecular weights of the polyurethanes ranged between 19,500 and 28,000 (weight‐average molecular weight/number‐average molecular weight = 1.71–2.15). All the polyurethanes exhibited excellent solubility in most common organic solvents, and this indicated that these polyurethanes offered good processability. The glass‐transition temperatures (T_g's) of the polyurethanes were in the range of 166–204°C. Among the polyurethanes, chromophores containing the nitrothiazole moiety exhibited lower T_g values in comparison with those of chromophores containing nitrobenzothiazole and nitrothiadiazole moieties. This was attributed to the small size of the nitrothiazole moiety in the polyurethane matrix. The polyurethanes containing a TDI backbone demonstrated relatively high T_g values in comparison with those of the polyurethanes containing an MDI backbone. This was a result of an enhancement of the rigidity caused by the incorporation of a toluene ring into the polyurethane backbone. The second harmonic generation (SHG) coefficients of the poled polyurethane films ranged from 67.29 to 105.45 pm/V at 1064 nm. High thermal endurance of the poled dipoles was observed for all the polyurethanes. This was attributed to the formation of extensive hydrogen bonds between urethane linkages. Furthermore, none of the developed polyurethanes showed SHG decay below 150°C, and this signified their acceptability for nonlinear optical devices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of temperature‐responsive poly(vinyl alcohol)‐based copolymers

A poly(vinyl alcohol) (PVA)/sodium acrylate (AANa) copolymer was synthesized to improve the water solubility of PVA at the ambient temperature. Furthermore, a series of temperature‐responsive acetalyzed poly(vinyl alcohol) (APVA)‐co‐AANa samples of various chain lengths, degrees of acetalysis (DAs), and comonomer contents were prepared via an acid‐catalysis process. Fourier transform infrared and ¹H‐NMR techniques were used to analyze the compositions of the copolymers. The measurement of the turbidity change for APVA‐co‐AANa aqueous solutions at different temperatures revealed that the lower critical solution temperature (LCST) of the copolymers could be tailored through the control of the molecular weight of the starting PVA‐co‐AANa, DA, and comonomer ratios. Lower LCSTs were observed for APVA‐co‐AANa with a longer chain length, a higher DA, and fewer acrylic acid segments. In addition, the LCSTs of the APVA‐co‐AANa aqueous solutions appeared to be salt‐sensitive. The LCSTs decreased as the concentration of NaCl increased. Moreover, atomic force microscopy images of APVA‐co‐AANa around the LCST also proved the temperature sensitivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Optimization of the electron‐beam‐lithography parameters for the moth‐eye effects of an antireflection matrix structure

In this study, we mainly used the characteristics of electron‐beam lithography in measurement control and direct‐write technology to improve the physical restrictions and production processes of optical lithography and other nanopattern production methods. We did this by using a silicon wafer as a substrate, coating a negative‐tone photoresist, and using scattering and the reflection produced by the collision of an electron beam with the wafer lattice and the proximity effect of a secondary electron inside the electron‐beam photoresist to produce an antireflection matrix structure with a moth‐eye effect. In addition, we used the Taguchi quality method with an orthogonal array to plan the experiment and the signal‐to‐noise ratio to analyze the experimental data, and in the experimental process, we produced a full factorial equivalent experiment, using very few experiment repetitions and deriving optimum conditions. Also, we used back‐propagation neural networks to fine‐tune significant factors, allowing the production of the deepest process control parameters and thereby imparting to the antireflection matrix structure the best effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5303–5313, 2006     

Synthesis of N‐β‐aminoethyl‐γ‐aminopropyl polydimethyl‐co‐polydiphenylsiloxane and its film morphology and orientation

A fabric softener, N‐β‐aminoethyl‐γ‐aminopropyl polydimethyl‐co‐polydiphenylsiloxane (PASO), was synthesized by the polymerization of octamethyl cyclotetrasiloxane with an amino‐functional silane and dimethyldiphenylsilane. The chemical structure of the synthesized polysiloxane was characterized by Fourier transform infrared and ¹H‐NMR spectra. The morphology, composition, and hydrophobic properties of the PASO film were investigated by X‐ray photoelectron spectroscopy, atomic force microscopy, contact angle measurement, and other measurements. The experimental results indicate that on the silicon wafer surface, PASO formed a hydrophobic, nonhomogeneous structural film. In addition, the atomic force microscopy results show that the PASO film deposited on the silicon wafer seemed to be slightly rougher than the film of the control, the N‐β‐aminoethyl‐γ‐aminopropyl polydimethylsiloxane. As a result, an orientation model of PASO is proposed on the basis of the characterization of the PASO film properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009