Conventional Radical Polymerization Research Articles

Bulk Depolymerization of Methacrylate Polymers via Pendent Group Activation.

In this study, we present an efficient approach for the depolymerization of poly(methyl methacrylate) (PMMA) copolymers synthesized via conventional radical polymerization. By incorporating low mol % phthalimide ester-containing monomers during the polymerization process, colorless and transparent polymers closely resembling unfunctionalized PMMA are obtained, which can achieve >95% reversion to methyl methacrylate (MMA). Notably, our catalyst-free bulk depolymerization method exhibits exceptional efficiency, even for high-molecular-weight polymers, including ultrahigh-molecular-weight (106-107 g/mol) PMMA, where near-quantitative depolymerization is achieved. Moreover, this approach yields polymer byproducts of significantly lower molecular weight, distinguishing it from bulk depolymerization methods initiated from chain ends. Furthermore, we extend our investigation to polymethacrylate networks, demonstrating high extents of depolymerization. This innovative depolymerization strategy offers promising opportunities for the development of sustainable polymethacrylate materials, holding great potential for various applications in polymer science.

Preparation and dispersion properties of polyacrylate copolymer dispersant

Purpose The purpose of this paper is to synthesize a polyacrylate-based dispersant with a determined target molecular weight for oily systems and to determine the optimal dispersant level and monomer ratio of the dispersant. Design/methodology/approach The dispersant was synthesized by conventional radical polymerization using methacrylic acid, butyl acrylate and dimethylamino ethyl methacrylate as the monomer. It was characterized by Fourier transform infrared spectroscopy, nuclear magnetic hydrogen spectroscopy, gel permeation chromatography and thermogravimetric analysis. The dispersant was used to disperse TiO2, and the performance of the dispersant was evaluated by measuring the viscosity, particle size and dispersive force of the slurry. Findings The dispersant exhibited high thermal stability and was successfully anchored to the surface of the TiO2 pigment. When used to disperse a TiO2 slurry, it effectively made the TiO2 slurry more fluid, indicating its strong viscosity-reducing properties. The viscosity, particle sizes and dispersion capabilities of the TiO2 slurry were found to vary depending on the contents and monomer ratios of the dispersant. Research limitations/implications P(MAA-BA-DM) dispersant increases the wettability of TiO2 only in oily solvents but not in aqueous solvents. Practical implications P(MAA-BA-DM) dispersant makes it easier to disperse TiO2 pigments in oily solvents, increasing the amount of pigment in the solvent and making the preparation of highly pigmented pastes easier. Originality/value A dispersant containing suitable carboxyl and tertiary amine groups was initially synthesized to disperse TiO2 in an oily system. The findings are anticipated to be used in the formulation of pigment concentrates, industrial coatings and other solvent-based coatings.

A hydrophilic near dissolved organic matter microfiltration (NDOM MF) membrane prepared using multifunctional porogen synthesized via metal-free atom transfer radical polymerization for highly efficient microplastic removal

Microplastic (MP) pollution has emerged as a global concern. One of the practical alternatives is a microfiltration (MF) process using MF membranes with a high MP removal rate and high water permeability simultaneously. In this study, we developed a highly permeable PVC-based MF membrane capable of effectively separating MP by using amphiphilic PVC, which can serve as a pore-forming agent during phase separation and as a hydrophilic modifier after solidification. We developed a new organic photocatalyst under UV light to synthesize amphiphilic PVC via metal-free atom transfer radical polymerization. With 3 wt% amphiphilic PVC, the mean pore size increased to 0.86 µm, which was 3 times larger than the control PVC membrane (0.25 µm). Furthermore, the modified PVC (m-PVC) membrane reduced the contact angle of the membrane from 80.6° to 58.3°, indicating a significant improvement in the hydrophilicity of the membrane. The larger pores and increased hydrophilic properties made the m-PVC membrane 15 times more permeable than the control, while still maintaining a removal rate of approximately 99.9 % in a water filtration test with a 1 µm bead solution. The modified PVC membrane also operated consistently under varying pH conditions. Lastly, the m-PVC membrane exhibited a 12 times lower transmembrane pressure than the control during the constant flux filtration test, resulting in a 5 times lower specific filtration energy despite a 2 times longer filtration time. We hope this study could contribute to creating a new trend in MP removal utilizing a highly porous MF membrane, which is cut out for highly efficient removal of particulate pollutants and high water permeability simultaneously.

Polymer-supported thioamide-derived cinchona alkaloids as efficient organocatalysts for the enantioselective decarboxylative protonation

A new family of copolymers based on styrene and a polymerizable cinchonidine thioamide derivative was synthesized by conventional radical polymerization. The copolymers were tested as homogeneous supported organocatalysts in the enantioselective decarboxylative protonation (EDP) of α-aminomalonate hemiesters giving access to α-amino acids under very mild conditions. These macromolecular catalysts could be prepared on a large scale and outperformed their unsupported analogues providing the desired products in high yield and enantioselectivity. Furthermore, recycling experiments were conducted which showed good enantioselectivities.

Synthesis of water-soluble NIR macro-photocatalysts from polymerizable zinc phthalocyanine

To improve the solubility and recyclability of the NIR photocatalyst, two synthetic strategies, namely “living” polymers with permanent NIR photocatalyst by reversible addition-fragmentation chain transfer (RAFT) polymerization and “non-living” polymers with recyclable NIR macro-photocatalyst (macro-PC) by conventional radical polymerization, were developed by copolymerization of hydrophilic and polymerizable zinc phthalocyanine (ZnTAPc-MAm or ZnTAPc-Am) monomers. The resultant macro-PCs from RAFT polymerization were endowed with permanent NIR photocatalysis due to the attachment of zinc phthalocyanine moieties, and the features of both “living” and permanent NIR photocatalyst of the “living” macro-PCs were verified by much simple multiple chain extensions via RAFT polymerization in water (only involved in “living” polymers and fresh monomer) under irradiation with NIR LED light (λmax = 730 nm) at room temperature. In addition, the resultant water-soluble “non-living” macro-PCs from conventional radical polymerization were endowed with only NIR photocatalysis property but they could be easily recycled just by centrifugation, which facilitates to synthesize tailored polymers by recyclable PCs under NIR irradiation.

Molecular Properties of Protonated Diallylammonium Polymers Synthesized via Reversible Addition−Fragmentation Chain-Transfer Polymerization

Protonated diallylammonium polymers are special among cationic polyelectrolytes, due to a series of properties including high antimicrobial activity, for example, towards Mycobacterium tuberculosis. The polymers samples should be characterized properly for their practical application. In this study, protonated secondary polydiallylamines based on diallylammonium trifluoroacetate have been synthesized via radical reversible addition−fragmentation chain-transfer polymerization in the presence of 2-[(ethoxycarbonothioyl)sulfanyl]acetic acid. The NMR spectroscopy data have shown that the macromolecules contain the dithiocarbonyl terminal groups enhancing the polymer solubility in nonaqueous media, for instance, in methanol. The obtained polymers have been investigated by means of hydrodynamics and dynamic light scattering methods; molecular mass and hydrodynamic parameters of the macromolecules have been determined. Comparison of the polymers with similar ones synthesized via conventional radical polymerization and bearing terminal vinyl groups has revealed the independence of their hydrodynamic properties in 1.0 mol/L NaCl on the synthesis method and the terminal groups structure at М 8 × 103, thus allowing the application of the scaling relationships for the diallylammonium polymers to determine the molecular mass, irrespectively on the preparation methods.

Novel Copper-Based Catalytic Systems for Atom Transfer Radical Polymerization of Acrylonitrile

Atom Transfer Radical Polymerization (ATRP) is an effective catalytic process leading to well-defined polymers with desired properties. This process based on reversible deactivation of propagating chains has a lower rate in comparison with conventional radical polymerization, especially in the case of obtaining polymers with high molecular weights. Thus, the increase of the rate of this process with preserving control over molecular weight distribution is a challenging task. In this work, novel catalytic systems for Activators Generated by Electron Transfer (AGET) ATRP of acrylonitrile based on copper (II) bromide complexes were proposed. It was found that Rochelle salt (potassium sodium tartrate tetrahydrate) may be used as a reducing agent for regeneration of copper-based catalysts to increase the rate of the process. The provided UV-vis spectroscopy experiments have confirmed the reducing ability of tartaric anion. It was found that the use tandem catalytic system based on two copper complexes with different ligands also increases the polymerization rate. The performed experiments allowed us to develop a catalytic system for rapidly obtaining polyacrylonitrile polymers with desired molecular weights exceeding 100 kDa.

Simple and safe liquid seal approach to oxygen-tolerant ATRP

Trace oxygen is fatal to the conventional reversible deactivation radical polymerization (RDRP), so it is necessary to eliminate the influence of oxygen through some strict deoxygenation operations or by adding external components (post-treatment required). Here, we report the effective barrier of oxygen dissolution in an open system built by a liquid seal. Two different liquid seal materials, liquid paraffin and lithium grease, are used in this work. Lithium grease materials can stably isolate oxygen at a high stirring speed (450 rpm) to intensify the heat and mass transfer processes during the reaction. An effective atom transfer radical polymerization (ATRP) could be assisted by simply adding liquid seal materials with a thickness of 5 mm, providing polymers with high conversion (≥90 %), controlled molecular weight, narrow molecular weight distribution (Mw/Mn ≤ 1.15) and high end-group fidelity. With this liquid seal strategy, dozens of grams of the polymer were obtained, which is expected to have potential industrial applications under ambient atmosphere and conditions.

EFFECTS OF EVEN FUNCTIONAL GROUP DISTRIBUTION IN EMULSION STYRENE–BUTADIENE RUBBER PREPARED BY REVERSIBLE ADDITION–FRAGMENTATION CHAIN TRANSFER POLYMERIZATION ON THE PROPERTIES OF SILICA-FILLED COMPOUNDS

ABSTRACT Recently, considerable attention has been paid to the development of new functionalized polymers to improve the fuel efficiency of vehicles by reducing the rolling resistance of tires to adhere to strict CO2 emission regulations. Accordingly, multifunctionalized (MF) reversible addition–fragmentation chain transfer (RAFT) emulsion styrene–butadiene rubbers (ESBR) were synthesized, in which chain-end and in-chain functionalization were performed simultaneously by introducing a third monomer (glycidyl methacrylate; GMA) using RAFT polymerization. Compared with GMA ESBR, in which GMA is introduced as a third monomer by conventional radical polymerization (CRP), there was an even distribution of GMA per chain in the MF-RAFT ESBR. After preparing the silica-filled compounds, vulcanizate structure analysis and mechanical property evaluation of the compounds were performed. The MF-RAFT ESBR prepared by RAFT polymerization exhibited superior in-chain functionalization efficiency compared with GMA ESBR prepared by CRP because of the even distribution of GMA and higher crosslink density. Consequently, MF-RAFT ESBR compound showed superior silica dispersion, abrasion resistance, and lower rolling resistance compared with the GMA ESBR compound.

Atom Transfer Radical Polymerization of Pyrrole-Bearing Methacrylate for Production of Carbonyl Iron Particles with Conducting Shell for Enhanced Electromagnetic Shielding.

The conducting polymer poly(2-(1H-pyrrole-1-yl)ethyl methacrylate (PPEMA) was synthesized by conventional atom transfer radical polymerization for the first time from free as well as surface-bonded alkyl bromide initiator. When grafted from the surface of carbonyl iron (CI) a substantial conducting shell on the magnetic core was obtained. Synthesis of the monomer as well as its polymer was confirmed using proton spectrum nuclear magnetic resonance (1H NMR). Polymers with various molar masses and low dispersity showed the variability of this approach, providing a system with a tailorable structure and brush-like morphology. Successful grafting from the CI surface was elucidate by transmission electron microscopy and Fourier-transform infrared spectroscopy. Very importantly, thanks to the targeted nanometer-scale shell thickness of the PPEMA coating, the magnetization properties of the particles were negligibly affected, as confirmed using vibration sample magnetometry. Smart elastomers (SE) consisting of bare CI or CI grafted with PPEMA chains (CI-PPEMA) and silicone elastomer were prepared and dynamic mechanical properties as well as interference shielding ones were investigated. It was found that short polymer chains grafted to the CI particles exhibited the plasticizing effect, which might be interesting from the magnetorheological point of view, and more interestingly, in comparison to the neat CI-based sample, it provided enhanced electromagnetic shielding of nearly 30 dB in thickness of 500 μm. Thus, SE containing the newly synthesized CI-PPEMA hybrid particles also exhibited considerably enhanced damping factor and proper mechanical performance, which make the material highly promising from various practical application points of view.

Fully Degradable Polyacrylate Networks from Conventional Radical Polymerization Enabled by Thionolactone Addition

Fully Degradable Polyacrylate Networks from Conventional Radical Polymerization Enabled by Thionolactone Addition

Poly(poly(ethylene glycol) methyl ether methacrylate-co-acrylonitrile) gel polymer electrolytes for high performance lithium ion batteries: Comparing controlled and conventional radical polymerization

In this work, a series of crosslinked poly(poly(ethylene glycol) methyl ether methacrylate-co-acrylonitrile) [P(PEGMA-co-ACN)] copolymers has been designed as gel polymer electrolytes (GPEs) for high-safety and high voltage lithium ion batteries. Two approaches including conventional free radical polymerization (FRP) and control radical polymerization (CRP) through one-step reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) were used to synthesize GPEs with different molar ratios of ACN and PEGMA. Although there was not observed remarkable advantage of polymerization method in different monomer compositions, P(PEGMA-co-ACN) by 50 mol.% ACN and PEGMA prepared via FRP exhibited the maximum ionic conductivity of 5.1 * 10−3 S cm−1, transference number (t+) of 0.55, and exceptional swelling ratio value of 150% in 30 min. Interestingly, it affords a supreme electrochemical stability window up to 5.13 V vs. Li/Li+, the charge capacity of 205 mAh g−1 at 0.1 C, and capacity retention of 89% after 100 cycles.

Poly(poly[ethylene glycol] methyl ether methacrylate)/graphene oxide nanocomposite gel polymer electrolytes prepared by controlled and conventional radical polymerizations for lithium ion batteries

Nanocomposite gel polymer electrolyte (GPE) films based on poly(poly[ethylene glycol] methyl ether methacrylate)/graphene oxide (GO) (P[PEGMA-GO]) have been prepared by in situ conventional free radical polymerization (FRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization as controlled radical polymerization (CRP) using 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) as RAFT agent. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that prepared nanocomposite films had amorphous structure and also, thermogravimetric analysis (TGA) showed appropriate thermal stability of samples. GPEs prepared via FRP showed slight higher ionic conductivity that GPEs prepared via RAFT polymerization. In both synthetic approaches, an optimum GO amount of 0.3 wt. % was obtained considering ionic conductivity. At ambient temperature, P(PEGMA-GO) with 0.3 wt. % GO prepared via FRP indicated the highest ionic conductivity of 4.05 × 10−3 S cm−1, a satisfactory lithium ion transference number (t+) of 0.6, and the excellent interface compatibility with electrodes. The lithium ion battery with P(PEGMA-GO0.3%) as GPE also exhibited electrochemical stability window up to 4.6 V vs. Li/Li+, a high charge-discharge capacity of 179 mAh g−1 at 0.1 C, and capacity retention of 91% after 100 cycles.

Dual Thermo- and Photo-Responsive Micelles Based on Azobenzene-Containing Random Copolymer.

Amphiphilic random copolymer poly(methacrylamido-azobenzene)-ran-poly(2-hydroxyethylacrylate) (PMAAAB-ran-PHEA) was synthesized via hydrolysis of poly(methacrylamido-azobenzene)-ran-poly[2-((2′-tetrahydropyranyl)oxy)ethylacrylate] (PMAAAB-ran-P(THP-HEA)), which was prepared by conventional radical polymerization. PMAAAB-ran-PHEA micelles were then prepared via dialysis method against water with DMF as solvent. The structure, morphology, size, and low critical solution temperature (LCST) of PMAAAB-ran-PHEA and its micelles were determined by 1H-NMR, GPC, TEM, and DLS. The thermo- and photo-responsive behaviors of the resulting polymer micelles were investigated with Nile red as a fluorescence probe. The results showed that PMAAAB-ran-PHEA micelles were porous or bowl-shaped and its size was 135–150 nm, and its LCST was 55 °C when FMAAAB of the random copolymer was 0.5351; the hydrophobicity of the micellar core was changed reversibly under the irradiation of UV light and visible light without release of Nile red or disruption of micelles; the size and solubilization capacity of the micelles were dependent on temperature, and Nile red would migrate for many times between the water phase and the micelles, and finally increasingly accumulated during the repeated heating and cooling processes.

One-step zwitterionization and quaternization of thick PDMAEMA layer grafted through subsurface-initiated ATRP for robust antibiofouling and antibacterial coating on PDMS

In this work, we demonstrate the grafting of thick poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA) layer on PDMS via subsurface-initiated atom transfer radical polymerization (SSI-ATRP). The self-migration of DMAEMA monomers into the subsurface of PDMS is proven to be the dominant factor for the success of SSI-ATRP. The as-prepared thick microscale graft layer on PDMS shows much better abrasion resistance than nanoscale graft layer obtained by conventional surface-initiated atom transfer radical polymerization (SI-ATRP) under identical condition. Taking advantage of the tertiary amines of PDMAEMA, the simultaneous zwitterionization and quaternization of the PDMAEMA thick layer is realized through a facile one-step process. The effect of zwitterionization and quaternization degree on the antibiofouling and antibacterial properties is investigated. The results show that a relatively high zwitterionization degree (75 mol%) and a low quaternization degree (25 mol%) exhibit a good well-balanced effect on both fouling repellence and bactericidal activity. This work may lead to the development of robust bifunctional antibiofouling and antibacterial surfaces via SSI-ATRP strategy.

Ubiquitous Nature of Rate Retardation in Reversible Addition-Fragmentation Chain Transfer Polymerization.

Reversible addition-fragmentation chain transfer (RAFT) polymerization is one of the most powerful reversible deactivation radical polymerization (RDRP) processes. Rate retardation is prevalent in RAFT and occurs when polymerization rates deviate from ideal conventional radical polymerization kinetics. Herein, we explore beyond what was initially thought to be the culprit of rate retardation: dithiobenzoate chain transfer agents (CTA) with more active monomers (MAMs). Remarkably, polymerizations showed that rate retardation occurs in systems encompassing the use of trithiocarbonates and xanthates CTAs with varying monomeric activities. Both the simple slow fragmentation and intermediate radical termination models show that retardation of all these systems can be described by using a single relationship for a variety of monomer reactivity and CTAs, suggesting rate retardation is a universal phenomenon of varying severity, independent of CTA composition and monomeric activity level.

Emulsion iodine transfer polymerization of nearly uniform submicrometer‐sized polystyrene particles

AbstractEmulsifier‐free emulsion iodine transfer polymerization (emulsion ITP) of styrene was carried out using unpurified and purified poly(methacrylic acid)–iodine (PMAA‐I). PMAA‐I was previously synthesized by solution ITP in dioxane. The solution ITP of methacrylic acid was completed at 40 °C for 24 h. Unexpectedly, 64% of added CHI3 remained in dioxane even after the polymerization. The emulsion ITP was carried out at pH ∼ 9 with unpurified or purified PMAA‐I. The number‐average diameter (dn) of the polymer particles obtained using purified PMAA‐I (148 nm at 93% conversion) was much smaller than that using unpurified PMAA‐I (710 nm at 68% conversion). In both cases, in the early stage of the polymerization, polystyrene (PS) particles stabilized by some PMAA‐b‐PS copolymer chains were formed. This indicates that PMAA‐I worked not only as a macro chain transfer agent but also as a colloidal stabilizer. In the unpurified system, the remaining CHI3 also operated as a chain transfer agent. It resulted in PS‐I homopolymers having controlled molecular weight in the PS particles. On the other hand, many high molecular weight PS homopolymers were formed in the purified system by emulsion conventional radical polymerization in the PS particles. To depress emulsion conventional radical polymerization, the CHI3 was post‐added after 90 min. Nearly uniform submicrometer‐sized (82 nm) PS particles with narrow molecular weight distribution (Mw/Mn = 1.24) were achieved. These polymerization behaviors were reasonably explained from the results obtained by gel permeation chromatography and diffusion ordered spectroscopy 1NMR. © 2021 Society of Industrial Chemistry.

Effects of graphite oxide on thermal and electrical behaviors of coumarin‐based methacrylate copolymers: Its single chain polymer molecule via intramolecular cyclobutane formation

AbstractThe random copolymers of methyl methacrylate (MMA) and 4‐methyl‐2‐oxo‐2H‐chromen‐7‐yl methacrylate (COUMA) [poly (COUMA0.49‐co‐MMA)] (COMCOP1) and [poly(COUMA0.36‐co‐MMA)] (COMCOP2) were prepared via the conventional radical polymerization method. The copolymers were characterized by 1H‐NMR, Fourier‐transform infrared spectroscopy (FT‐IR), UV–visible (UV–vis), thermogravimetric analysis, and differential scanning calorimetry instruments. A kinetic study of the thermal decomposition of COMCOP1 and COMCOP1/GO 16 wt% was investigated using thermogravimetric analyzer with non‐isothermal methods selected for analyzing solid‐state kinetics data. The average activation energy values were calculated via Flynn Wall and Ozawa (FWO) and Kissinger‐Akahira‐Sunose models in a period of α = 0.10–0.70. The average values of activation energy obtained from Kissinger method for COMCOP1 and COMCOP1/GO 16 wt% were 94.5 and 78.4 kJ/mol, respectively, whereas, those of estimated by FWO method were 103.5 and 87.0 kJ/mol. We indicate that well‐defined single chain polymer molecule (SCPM) via intramolecular cyclobutane formation could be obtained by the intrachain photodimerization of coumarin groups during UV irradiation at 365 nm diluted solution of COMCOP1. The photodimerization of coumarin groups in the copolymer was confirmed by UV–vis, FT‐IR, and 1H‐NMR instruments. Dielectric and electrical behaviors of the composites having a semiconductor behavior filled GO were investigated. The activation energy values based on dc conductivity for COMCOP1 loaded GO 10 and 12 wt% were decreased from 0.206 to 0.069 eV. Also, the Ea values estimated for COMCOP2‐loaded GO 12 and 13.6 wt% were 0.0580 and 0.0859 eV, respectively.

Controlled Radical Polymerization: from Oxygen Inhibition and Tolerance to Oxygen Initiation

Molecular oxygen is a radical scavenger in both conventional and controlled radical polymerization (CRP), resulting in many time-consuming methods for physically removing oxygen before the polymerization. Different approaches have been developed to have oxygen tolerance by chemically consuming or converting molecular oxygen into non-initiating species to address this issue. Recently, we propose another approach called oxygen initiation that directly transforms molecular oxygen into the initiating carbon radical in CRP. This Feature Article summarizes our recent developments in this direction. Oxygen-initiated reversible addition-fragmentation transfer (RAFT) polymerization has been successfully conducted using oxygen and trialkylborane as co-initiators under the ambient conditions and atmosphere without any prior degassed procedures. This gas-trigger initiation provides the opportunity for spatiotemporal control of the polymerization by molecular oxygen or air. Rationally synthesized alkylborane compounds could derive the predesigned structure of the initiating alkyl radical to minimize the side reactions and free polymer chains, achieving the synthesis of ultra-high molecular weight polymers. The challenges and perspectives are also discussed at the end.

Long-lasting hydrophilic surface generated on poly(dimethyl siloxane) with photoreactive zwitterionic polymers

Poly(dimethylsiloxane) (PDMS) is known as one of the most established polymers for making elastomers. Therefore, it is commonly used for the fabrication of biomedical devices. Many PDMS surface modification processes have been proposed recently to increase PDMS reliability in medical fields. However, the modified surface's long-term stability is still limited. Hydrophobic recovery of PDMS is widely recognized as a factor that reduces the efficacy of PDMS surface modification. The photoreactive zwitterionic polymer effectively suppresses the hydrophobic recovery of PDMS, according to the current analysis. The photoreactive zwitterionic monomer, 2-[2-(Methacryloyloxy)ethyldimethylanmmonium] ethyl benzophenoxy phosphate (MBPP) was polymerized by conventional radical polymerization and coated on O2-plasma-treated PDMS specimens. The specimens were immersed in an aqueous solution of 2-methacryloyloxyethyl phosphorylcholine (MPC) and exposed under ultraviolet (UV) radiation for 3 h. Instead, of poly(MBPP) (PMBPP), benzophenone (BP) was also used as a conventional photoinitiator. The time-dependent change in the wettability and elemental composition of the specimen surface was monitored for nine weeks after photo-grafting of poly[2-methacryloyloxyethyl phosphorylcholine (MPC)] (PMPC). The advancing and receding contact angles (θA/θR) of the pristine PDMS specimen were 112°/71° and significantly decreased immediately after the grafting of PMPC regardless of types of photoinitiator. However, the hydrophobicity of the surface gradually recovered, and θA was changed from 12° to 81° for nine weeks of storage under air atmosphere when BP was used as a photoinitiator for graft polymerization of MPC. However, surface hydrophilicity (θA ≅ 20°) of the surface grafted with PMPC with PMBPP as an initiator was effectively preserved for nine weeks. This surface also showed excellent lubricity and non-fouling properties regardless of the storage periods. Therefore, zwitterionic photoreactive polymer, PMBPP, is then used as a macrophotoinitiator for the surface modification of PDMS.