Photopolymerization Of Monomers Research Articles

Preparation and characterization of interpenetrating networks based on polyacrylates and poly(lactic acid)

Three different, multifunctional acrylic monomers were photopolymerized in a matrix of poly(lactic acid), PLA, using 2-hydroxy-2-methyl-1-phenyl-propan-1-one as a photoinitiator. The kinetics of the photopolymerization of monomers in PLA, studied with Fourier Transform Infrared Spectroscopy, has been compared to analogous processes of pure monomers under the same conditions (room temperature, air atmosphere). Additionally, poly(ethylene glycol) was added to acrylate/PLA blends as plasticizer.The highly crosslinked networks obtained were characterized by FTIR and optical microscopy. The amount of insoluble gel has been estimated gravimetrically. It was found that the studied systems are char- acterized by very high polymerization rate, moreover, efficient grafting of polyacrylates on PLA takes place. The observed morphology indicates the heterogeneity of formed networks. The glass transition temperature of PLA in studied blends has been determined by differential scanning calorimetry.

A facile sol–gel synthesis of crack-free photopolymerizable silica for holographic recording

A series of sol–gel based photopolymerizable silica glass for holographic storage has been synthesized via a facile chemical design in an effort to overcome the cracking problem incurred during the irradiation stage. The holographic composite material includes a low molecular weight polydimethylsiloxane (PDMS) with end-capped hydroxyl groups, an epoxide-containing coupling agent, a photopolymerizable acrylate monomer, and the sol–gel-derived silica matrix. Inclusion of PDMS provides improved compression stress and strain and toughness over the original unmodified samples, without deterioration on the diffraction efficiency (η). A plateau value of η~40% can be found under a beam power of 5.02mW. Correlation between the molecular weight of acrylate polymer and η of the holographic composite material is described and the discrepancies are analyzed. The premature saturation of polymerization in the holographic system is attributed to the retarded free radical polymerization within the silica matrix. Minor variation of η with photoinitiator concentration is observed, indicating that only moderate molecular weight is required for a reasonably high η. Based on the chemical and physical interactions within the material system, a crack-free mechanism is elucidated. Finally, the adverse effect of the residual photoinitiator on the holographic media is addressed.

A Water-Compatible NHC-Borane: Photopolymerizations in Water and Rate Constants for Elementary Radical Reactions.

Rate constants for important elementary reactions of 2,4-dimethyl-1,2,4-triazol-3-ylidene borane (1) and its derived boryl radical have been measured in the presence and absence of water. Reactions including H-abstraction by tBuO•, and onward reactions of the derived radical with methyl acrylate (addition), iodopropane (halogen abstraction), and an iodonium salt (oxidation) are unaffected by the presence of a high concentration (1.5 M) of water. Extending these results, borane (1) has been found to be an efficient new co-initiator for the visible light photopolymerization of monomers in the presence of both air and water.

Hybrid Organic/Inorganic Thiol–Ene-Based Photopolymerized Networks

The thiol-ene reaction serves as a more oxygen tolerant alternative to traditional (meth)acrylate chemistry for forming photopolymerized networks with numerous desirable attributes including energy absorption, optical clarity, and reduced shrinkage stress. However, when utilizing commercially available monomers, many thiol-ene networks also exhibit decreases in properties such as glass transition temperature (T(g)) and crosslink density. In this study, hybrid organic/inorganic thiol-ene resins incorporating silsesquioxane (SSQ) species into the photopolymerized networks were investigated as a route to improve these properties. Thiol- and ene-functionalized SSQs (SH-SSQ and allyl-SSQ, respectively) were synthesized via alkoxysilane hydrolysis/condensation chemistry, using a photopolymerizable monomer [either pentaerythriol tetrakis(3-mercaptopropionate) (PETMP) or 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO)] as the reaction solvent. The resulting SSQ-containing solutions (SSQ-PETMP and SSQ-TATATO) were characterized, and their incorporation into photopolymerized networks was evaluated.

Two‐Photon Polymerization of Biocompatible Photopolymers for Microstructured 3D Biointerfaces

AbstractThree‐dimensional microstructured scaffolds provide a means for cells to be cultured in vitro in a way that resembles natural conditions more closely than flat tissue culture polystyrene. In the presented work, two‐photon polymerization (2PP) is applied as a tool for the engineering of high‐resolution 3D scaffold structures with a well defined microarchitecture made of biocompatible photo resins. 2PP is a novel photolithographic technique using femtosecond laser pulses which enables free 3D microstructuring of liquid photo resins due to the relationship of the axial and lateral spatial confinement of the photoreaction to the focal volume of a focused laser beam. A set of photo resins were tested with regard to 2PP processability and three different classes of methacrylated photopolymerizable monomers (methacrylated oligolactones, urethane dimethacrylate, poly(ethylene glycol diacrylate)) were found to be efficient 2PP materials. 3D microstructures based on computer models were produced and tested for biocompatibility. The initial cell adhesion and the viability of bovine chondrocytes on the polymeric scaffolds were evaluated morphologically by confocal laser scanning microscopy (CLSM) after three‐day culture on 2PP derived microstructures. 2PP derived scaffolds were fabricated in different sizes and geometries, starting from the 100 µm‐range reaching out to the cm‐range showing the actual possibilities to produce large volume scaffolds even for implantation purposes.

Cholesteric Liquid Crystalline Materials with a Dual Circularly Polarized Light Reflection Band Fixed at Room Temperature

An unpolarized normal-incidence light beam reflected by a cholesteric liquid crystal is left- or right-circularly polarized, in the cholesteric temperature range. In this article, we present a novel approach for fabricating a cholesteric liquid crystalline material that exhibits reflection bands with both senses of polarization at room temperature. A cholesteric liquid crystal that presents a twist inversion at a critical temperature T(c) is blended with a small quantity of photopolymerizable monomers. Upon ultraviolet irradiation above T(c), the liquid crystal becomes a polymer-stabilized liquid crystal. Below T(c), the material reflects a dual circularly polarized band in the infrared. By quenching the experimental cell at a temperature below the blend's melting point, the optical properties of the material in an undercooled state are conserved for months at room temperature, which is critical to potential applications such as heat-repelling windows and polarization-independent photonic devices.

Distributed feedback dye laser holographically induced in improved organic–inorganic photocurable nanocomposites

Distributed feedback (DFB) lasing in permanent volume transmission gratings formed in a laser dye-doped organic–inorganic nanocomposite has been investigated. DFB laser cavities were fabricated using one-step two-beam holographic exposure of Pyrromethene 567 (PM567) doped photopolymerizable acrylate monomers containing inorganic (LaPO4) nanoparticles. Compared to the formulation previously utilized, the material composition presented provides longer lifetime of the laser. Spectral and polarization properties, input–output and stability characteristics of the laser output have been investigated by varying the material composition and the patterning parameters. DFB lasing emission of the second and the third diffraction orders has been demonstrated. The spectral linewidth of ∼0.08 nm has been observed at a pump energy threshold of about 0.2 μJ/pulse for the second-order DFB lasing when pumped with 532 nm 500 ps laser pulses. Spectral tuning of the lasing output over ∼56 and ∼7 nm was obtained by varying the grating period and the content of inorganic nanoparticles in the polymer matrix, respectively.

SILICONE HYDROGELS WITH INTERPENETRATING NETWORK STRUCTURE PREPARED BY SIMULTANEOUS FREE-RADICAL/CATIONIC HYBRID POLYMERIZATIONS

Silicone hydrogels with interpenetrating network (IPN) structure were prepared by ultraviolet (UV)-initiated simultaneous free-radical/cationic polymerizations in order to develop contact lens with high performances. The polymerization mechanism was investigated by gel fraction method using polymerization of 2-hydroxyethyl methacrylate (HEMA) and 4-hydroxybutyl vinyl ether (HBVE) as a model. The results showed that HEMA and crosslinker ethylene glycol dimethacrylate (EGDMA) polymerized by free-radical mechanism, while HBVE and crosslinker triethylene glycol divinyl ether (DVE-3) polymerized by cationic mechanism. The IPN silicone hydrogels were then prepared by UV-initiated hybrid photopolymerization of monomers including HEMA and bitelechelic polydimethylsiloxane bearing vinyl ethers end-groups (VS) in the presence of free-radical and cationic photoinitiators. Physiochemical properties such as optical properties, ion permeability, contact angle, and mechanical properties of the silicone hydrogels were characterized by UV spectroscopy, ionoflux technique, and tensile tester. The results revealed that the water content, surface wettability, and ion permeability of the hydrogels increased, but the tensile strength and Young's modulus decreased with the increase of the HEMA content.

Synthesis of Photopolymerizable Hydrophilic Macromers and Evaluation of Their Applicability as Reactive Resin Components for the Fabrication of Three‐Dimensionally Structured Hydrogel Matrices by 2‐Photon‐Polymerization

AbstractTwo‐photon polymerization (2‐PP) is a promising new photolithographic technique to fabricate three‐dimensional (3D), micro‐ and nano‐structured tissue engineering scaffolds from photopolymerizable monomers. Although various photo resins are known for the use in 2‐PP, there is currently a need for photo‐curable monomers processable by 2‐PP to generate biocompatible 3D‐structured hydrogel materials for soft or cartilage tissue regeneration. In the present work hydrophilic methacrylate monomers and macromers based on synthetic poly(glycerine) and poly(ethylene glycol) urethanes as well as on the biopolymers dextran and hyaluronan is prepared. The photopolymerization behavior of these substances are investigated and formed hydrogel networks are studied with regard to their mechanical properties, cytocompatibility, and hydrolytic degradation. Based on these examinations simple 3D model structures are fabricated from these photo‐curable monomers and macromers by 2‐PP. It is shown that both the synthetic monomers and the dextran methacrylate macromer are efficient 2‐PP starting materials whereas the hyaluronan methacrylate can be used for 2‐PP only in combination with suitable water‐soluble co‐monomers. No cytotoxic effects are found in preliminary chondrocyte cultivation experiments on 2‐PP‐fabricated scaffolds but initial cell adhesion on the hydrophilic scaffold surfaces is rather low and has to be further improved to apply these structures in tissue engineering.

Chronological Investigations of Raman–Nath Diffraction Grating Inscribed by Direct Laser Writing in Photoreactive Monomer Base Mixtures

Phase-type diffraction gratings, inscribed using an ultraviolet laser beam, were grown in a thin film of a photoreactive monomer base mixture over a period of several hours. The photopolymerization of monomers and subsequent molecular migrations generated both surface relief gratings and inner refractive index modulation. The changes in the diffraction intensity over time revealed the pronounced behavior of grating formation, which can be explained using a time-dependent model based on the Raman–Nath diffraction theory. Homogeneous irradiation with ultraviolet light during the growth enabled us to fix the diffraction characteristics of the gratings at an arbitrary moment in time, allowing us to tailor the resultant diffraction gratings according to a desired specification. This sequential process can have practical applications.

Performance of amidocoumarins as probes for monitoring of cationic photopolymerization of monomers by fluorescence probe technology

AbstractThe performance of 7‐benzamido‐4‐methylcoumarin (B) and 7‐acetamido‐4‐methylcoumarin (C) as fluorescent probes for monitoring of progress of cationic photopolymerization of monomers by fluorescence probe technology has been evaluated in comparison with 7‐diethylamino‐4‐methylcoumarin (A). It has been found that the probes B and C do not cause such a delay of the polymerization start as the probe A does, but in the case of B and C, the cure monitoring using the fluorescence intensity ratio at two wavelengths as an indicator of the polymerization progress is not applicable. An alternative monitoring parameter has been applied successfully and a method for compensation of the effects of probe photolysis is proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

이중경화법을 이용한 열개시제 및 광개시제가 배합된 황칠도료의 경화속도 촉진 및 물성향상 연구

한반도 남부 일대에서 자생하는 황칠나무(Dendropanax morbifera Lev.) 수액으로부터 추출한 천연 도료인 황칠도료(Korean Dendropanax lacquer)는 예로부터 귀중한 예술품이나 투구, 화살, 활 등의 전쟁도구를 찬란한 황금색으로 도장하는데 사용되어 왔다. 경화 후 황금색의 투명한 도막을 형성하여 우수한 색상특성을 지니고 있을 뿐만 아니라 내후성, 내수성, 내식성 등이 우수하여, 보호도장으로써도 훌륭한 가치를 지니고 있다. 그러나 이러한 많은 장점에도 불구하고, 현대적인 여러 적용분야에 사용되지 못하고 있는 이유는 황칠도료의 생산량이 적고, 이로 인하여 가격이 매우 고가이고, 장시간의 경화시간이 소요되는 문제도 큰 원인으로 작용하고 있다. 한편 황칠 내에 광중합이 가능한 conjugated diene을 포함한 모노머가 있으며, 이러한 모노머는 일광 조사 조건등에 의하여 짧은 시간에 단단하고 황금색을 띠는 도막을 형성할 수 있음이 보고된 바가 있다. 따라서 본 연구에 서는 전통적인 황칠도료의 경화방법을 개선하고 경화속도를 촉진하기 위하여, 열개시제를 도입하여 열경화를 촉진하는 방법과 열개시제 및 광개시제를 동시에 도입하고 이중경화(dual curing)에 의해서 경화속도를 촉진하고자 하였다. 이러한 경화 속도 및 경화 거동은 적외선분광분석기(FT-IR)을 이용하여 -C=C- 이중결합 특성피크의 변화를 관찰하거나, 진자경도계(pendulum hardness tester)를 이용하여 표면 경도의 변화를 관찰함으로써 평가하였다. 또한 강체진자물성측정기(RPT)에 spot UV curing 장비를 도입하여 이중경화에 의한 경화 속도 진을 평가하였다. 본 연구의 결과 열개시제에 의하여 열경화가 촉진될 수 있을 뿐만 아니라, 이중경화에 의하여 경화속도를 향상시킬 수 있음을 확인하였다. 또한 이러한 황칠도료 경화 속도 촉진 방법을 활용하여 전통적인 역에만 사용되어온 황칠도료를 현대적인 여러 적용분야에도 확대하여 사용할 수 있는 가능성을 제시하였다. The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.

Photopolymerization of poly(ethylene glycol) dimethacrylates: The influence of ionic liquids on the formulation and the properties of the resultant polymer materials

AbstractThe photo‐initiated polymerization of poly(ethylene glycol)dimethacrylates [PEGDM(n)] in the presence of various ionic liquids (ILs) is reported. The influence of ILs concentrations as well as of their nature upon the photopolymerization kinetics was studied in detail. It was found that according to reactive ability in bulk and in solution photopolymerization, the investigated monomers can be divided into two groups: PEGDM(1)–PEGDM(2)–PEGDM(3) and PEGDM(4)–PEGDM(7‐8). ILs slightly influence the photopolymerization of monomers from the first group and greatly change kinetics of those from the second. Such behavior was explained by the theory of “kinetically favorable or unfavorable monomer associations.” It was demonstrated that certain ILs accelerate the photopolymerization of the highest PEGDMs and offer access to the polymers derived from low reactive monomers. Relying on the obtained data, the attempt to predict the structure of the “best” ionic additive for the given monomer photopolymerization was performed and proved. Finally, the influence of both residual and specially added ILs quantities upon the properties of obtained polymer materials was investigated. It was revealed that ILs can physically interact with polymer networks increasing their thermal stability, plasticizing films, and blocks, imparting ionic conductivity equal up to 3.62 × 10−3 Sm/cm at 25 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2388–2409, 2010

2-beam Coupling 방법을 이용한 광 고분자 형광 패턴 형성

아크릴레이트계 모노머를 사용한 최적화 된 포토폴리머에 안트라센 형광폴리머를 첨가하여 형광 특성을 가지는 포토폴리머를 제조하고, 514 nm 레이저를 이용하여 2-beam coupling 방법으로 형광 포토폴리머 필름 위에 회절격자를 형성하였다. 기록 시작 후 30초 이내에 선명한 fluorescent line pattern 이 형성되었으며, 회절격자 형성 뒤, 패턴이 형성된 부분에서 형광 세기의 증가가 관찰되었다. 기록 시 간섭 빔 앞에 mask pattern 을 이용하여 <TEX>$50\;{\mu}m$</TEX> gap electrode 패턴을 형성하였다. 이 때 형성된 패턴은 micron scale gap패턴 안에 회절격자로부터 생성된 submicron scale의 grating line을 보였다. 이는 beam의 광 고분자 film 표면에 대한 각도(<TEX>$3.6^{\circ}$</TEX>, <TEX>$15^{\circ}$</TEX>), 패턴에 사용된 광 고분자의 굴절률 등으로부터 Bragg's equation 을 사용하여 계산된 이론적인 grating 간격 (<TEX>$0.6\;{\mu}m$</TEX>) 과 오차범위 안에서 일치 하였다. Fluorescent photopolymer film was prepared with composition containing acrylate monomer, binder, a visible light sensitive photo initiator, and fluorescent anthracene polymer. A fluorescent grating pattern was inscribed on the photopolymer film using a 2-beam coupling method. A 514 nm laser was coupled to generate a beam-interference pattern. A highly fluorescent diffractive line pattern was formed on the fluorescent photopolymer within 30 sec. of exposure. The fluorescence intensity was highly enhanced in the patterned area, possibly due to the change in the environment of the fluorescent polymers by the photo-polymerization of monomers. Under a photo-mask, a gap electrode pattern was formed of fluorescent gratings with a sub-micron scale, which was matched well to the calculated value (<TEX>$2.5\;{\mu}m$</TEX> and <TEX>$0.6\;{\mu}m$</TEX>) based on the refractive index of the photopolymer and beam incident angle (<TEX>$3.4^{\circ}$</TEX>, <TEX>$15^{\circ}$</TEX>) to the photopolymer surface.

Novel diol spiro orthocarbonates derived from glycerol as anti‐shrinkage additives for the cationic photopolymerization of epoxy monomers

AbstractShrinkage that takes place during polymerizations induces internal stress in polymeric materials generating a series of problems like poor adhesion to substrates and delamination in coatings or microcracks and microvoids in composites. Some additives like spiro orthocarbonates can reduce or eliminate this shrinkage. This paper deals with the synthesis of novel diol spiro orthocarbonates (DIOL SOCs) and their effect as anti‐shrinkage additives in the photopolymerization of the monomer 3,4‐epoxycyclohexyl‐3′, 4′‐epoxycyclohexanecarboxylate. It was found that increasing the concentration of the DIOL SOCs resulted in higher conversion of the monomer due to the presence of hydroxyl groups. The viscoelastic properties of the polymer products were also measured. It was observed that at 5 mol% of the mixture of DIOL SOCs there was an increase in the storage modulus due to the crosslinking produced by the bifunctional SOCs. However, at higher concentrations, a decrease in the storage modulus was observed. The level of shrinkage using the DIOL SOCs at 20 mol% was reduced by 45% when compared to the case without any additive. DIOL SOCs can be easily prepared by reacting glycerol with tetraethylorthocarbonate. These additives reduced significantly the level of shrinkage of the polyether derived from the diepoxycyclohexane monomer. Copyright © 2010 Society of Chemical Industry

Holographic assembly of semiconductor CdSe quantum dots in polymer for volume Bragg grating structures with diffraction efficiency near 100%

We report on the fabrication of centimeter-size transmission Bragg gratings in semiconductor CdSe quantum dots dispersed 50 μm thick photopolymer films. This was done by holographic assembly of CdSe quantum dots in a photopolymerizable monomer blend. Periodic patterning of CdSe quantum dots in polymer was confirmed by a fluorescence microscope and confocal Raman imaging. The diffraction efficiency from the grating of 1 μm spacing was near 100% in the green with 0.34 vol % CdSe quantum dots, giving the refractive index modulation as large as 5.1×10−3.

Multifunctional photoreactive inorganic cages for three-dimensional holographic data storage

We demonstrate a holographic photopolymer based on multifunctional photoreactive inorganic cages, polyhedral oligomeric silsesquioxane (POSS). It is shown that a second photopolymerizable monomer, POSS, for the photopolymer, contributes to significantly enhance photosensitivity as well as refractive index modulation (Deltan). We also found that during the formation of holographic gratings, polymerization of POSS could effectively suppress volume shrinkage of photopolymer resin, owing to its filler-strengthening effect of inorganic cages accompanied with interpenetrating effect.

Fiber-to-Fiber Optical Gain of Polymer-Based Amplifier with Self-Written Active Waveguide

This paper describes optical amplification properties of an organic dye-doped polymer waveguide fabricated with a technique of self-written active (SWA) waveguide. The SWA waveguide has a fiber-type channel waveguide structure, which can be easily fabricated by laser light irradiation to a mixture of photopolymerizable monomer and the organic dye. In a 1.17-mm-long SWA waveguide under 610-nm optical pumping, the fiber-to-fiber optical gain of 20.3 dB was obtained for a 780-nm input light. Furthermore, it was demonstrated that the optical coupling between the channel gain waveguide and the input and output fiber ports could be minimized by using the SWA waveguide technique. The gain bandwidth was found to be as large as 50 THz (690–785 nm).

Optimization of multicomponent photopolymer formulations using high‐throughput analysis and kinetic modeling

AbstractWhile high throughput and combinatorial techniques have played an instrumental role in materials development and implementation, numerous problems in materials science and engineering are too complex and necessitate a prohibitive number of experiments, even when considering high throughput and combinatorial approaches, for a comprehensive approach to materials design. Here, we propose a unique combination of high throughput experiments focused on binary formulations that, in combination with advanced modeling, has the potential to facilitate true materials design and optimization in ternary and more complex systems for which experiments are never required. Extensive research on the development of photopolymerizable monomer formulations has produced a vast array of potential monomer/comonomer, initiator and additive combinations. This array dramatically expands the range of material properties that are achievable; however, the vast number of potential formulations has eliminated any possibility of comprehensive materials design or optimization. This limitation is addressed by maximizing the benefits and unique capabilities of high throughput experimentation coupled with predictive models for material behavior and properties. The high throughput experimentation‐model combination is useful to collect a limited amount of data from as few as 11 experiments on binary combinations of 10 analyzed monomers, and then use this limited data set to predict and optimize formulation properties in ternary resins that would have necessitated at least 1000 high throughput experiments and several orders of magnitude greater numbers of traditional experiments. A data analysis approach is demonstrated, and the model development and implementation for one model application in which a range of material properties are prescribed, and an optimal formulation that meets those properties is predicted and evaluated. © 2009 American Institute of Chemical Engineers AIChE J, 2010

TiO2나노 입자를 첨가한 광고분자 필름의 회절효율 값에 대한 연구

본 연구에서는 광고분자의 광특성을 향상시키기 위하여, <TEX>$TiO_2$</TEX>를 첨가시킨 광고분자를 제조하고, 그 광학 특성을 연구하였다. 광고 분자는 PVA를 바인더로, AA를 모노머로, TEOA를 개시제로, Eosin Y를 광감각제로 사용하여 제조하였다. 균일한 두께의 광고분자 필름을 얻기 위하여, 스핀 쿼터를 이용하여 일정양의 광고분자 용액을 슬라이드 글라스에 펼쳐 제조하였다. 건조 조건은 <TEX>$25^{\circ}C$</TEX>, 습도 60%, 72시간을 유지하였고, 이렇게 제작된 광고분자 필름을 <TEX>$20{\sim}70$</TEX>도 범위의 다양한 입사각에서 회절효율을 측정하였다. 그 결과, <TEX>$TiO_2$</TEX>가 첨가된 광고분자 필름은 무첨가 필름보다 5% 정도 높은 회절효율 값을 나타내었다. 뿐만 아니라, <TEX>$TiO_2$</TEX>의 첨가는 넓은 입사각 범위에서도 높은 효율을 나타내는데 효과적이었다. In order to improve the diffraction efficiency of the photopolymer, we prepared a <TEX>$TiO_2$</TEX> added photopolymer and investigated the optical properties. Prepared photopolymer films are based on polyvinyl alcohol (PVA) as a polymer binder, acryl amide (AA) as a photo-polymerizable monomer, triethanolamine (TEOA) as an initiator, and eosin Y as a sensitizer at 532 nm. To prepare the photopolymer films with the uniform thickness, the constant amount (2.5 ml) of the photopolymer solution was dropped on the glass and spread using a spin coater. Then films were dried for 72 hrs in a darkroom (<TEX>$20^{\circ}C$</TEX>, 40% RH) prior to the optical measurement. Then, the diffraction efficiencies of both the photopolymer films containing <TEX>$TiO_2$</TEX> and non-contained films were measured with the various incident angles (<TEX>$20{\sim}70^{\circ}$</TEX>). Therefore, <TEX>$TiO_2$</TEX> added photopolymer showed 5% higher diffraction efficiency than neat photopolymer without <TEX>$TiO_2$</TEX> addition. The addition of <TEX>$TiO_2$</TEX> into the photopolymer showed the high diffraction efficiency (over 70%) at broad range (<TEX>$20{\sim}70^{\circ}C$</TEX>) of the incident angle.