Miscibility of block copolymers of poly(ε‐caprolactone) and poly(ethylene glycol) with poly(3‐hydroxybutyrate) as well as the compatibilizing effect of these copolymers in blends of poly(ε‐caprolactone) and poly(3‐hydroxybutyrate)

Atactic poly(3‐hydroxybutyrate) (a‐PHB) and block copolymers of poly(ethylene glycol) (PEG) with poly(ε‐caprolactone) (PCL‐b‐PEG) were synthesized through anionic polymerization and coordination polymerization, respectively. As demonstrated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) measurements, both chemosynthesized a‐PHB and biosynthesized isotactic PHB (i‐PHB) are miscible with the PEG segment phase of PCL‐b‐PEGs. However, there is no evidence showing miscibility between both PHBs and the PCL segment phase of the copolymer even though PCL has been block‐copolymerized with PEG. Based on these results, PCL‐b‐PEG was added, as a compatibilizer, to both the PCL/a‐PHB blends and the PCL i‐PHB blends. The blend films were obtained through the evaporation of chloroform solutions of mixed components. Excitingly, the improvement in mechanical properties of PCL/PHB blends was achieved as anticipated initially upon the addition of PCL‐b‐PEG. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2600–2608, 2001     

Synthesis and characterization of poly(ε‐caprolactone)‐b‐poly(ethylene glycol)‐b‐poly(ε‐caprolactone) triblock copolymers with dibutylmagnesium as catalyst

Two series of poly(ε‐caprolactone)‐b‐poly(ethylene glycol)‐b‐poly(ε‐caprolactone) triblock copolymers were prepared by the ring opening polymerization of ε‐caprolactone in the presence of poly(ethylene glycol) and dibutylmagnesium in 1,4‐dioxane solution at 70°C. The triblock structure and molecular weight of the copolymers were analyzed and confirmed by ¹H NMR, ¹³C NMR, FTIR, and gel permeation chromatography. The crystallization and thermal properties of the copolymers were investigated by wide‐angle X‐ray diffraction (WAXD) and differential scanning calorimetry (DSC). The results illustrated that the crystallization and melting behaviors of the copolymers were depended on the copolymer composition and the relative length of each block in copolymers. Crystallization exothermal peaks (T_c) and melting endothermic peaks (T_m) of PEG block were significantly influenced by the relative length of PCL blocks, due to the hindrance of the lateral PCL blocks. With increasing of the length of PCL blocks, the diffraction and the melting peak of PEG block disappeared gradually in the WAXD patterns and DSC curves, respectively. In contrast, the crystallization of PCL blocks was not suppressed by the middle PEG block. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of diblock copolymers consisting of methoxy poly(ethylene glycol) and poly(ε‐caprolactone)/poly(L‐lactide) and their degradation property

Methoxy poly(ethylene glycol)‐b‐poly(ε‐caprolactone) (MPEG‐PCL) or MPEG‐b‐poly(L ‐lactide) (MPEG‐PLLA) diblock copolymers were prepared by the polymerization of CL or LA, using MPEG as an initiator in the presence of stannous octoate. MPEG‐b‐poly(ε‐caprolactone‐ran‐L ‐lactide) (MPEG‐PCLA) diblock copolymers with different chemical composition of PCL and PLLA were also prepared by adjusting the amount of CL and LA from MPEG in the presence of stannous octoate. In degradation study, the degradation of the MPEG‐PCLA diblock copolymers mainly depends on the PCL and PLLA segments present in their structure. MPEG‐PCLA, with intermediate ratio of PCL and PLLA segment, completely degraded after 14 weeks. Meanwhile, partially degraded MPEG‐PCLA segments and parent MPEG segments were observed at higher PCL or PLLA segment contents. Introduction of PLLA into the PCL segments caused a lowering of the crystallinity of the diblock copolymers, thus, inducing a faster incoming of water into the copolymers. We confirmed that the diblock copolymers, with lower degree of crystallinity, have degraded more rapidly. POLYM. ENG. SCI., 46: 1242–1249, 2006. © 2006 Society of Plastics Engineers     

Synthesis,characterization and biocompatibility of novel biodegradable poly[((R)‐3‐hydroxybutyrate)‐block‐(D,L‐lactide)‐block‐(ε‐caprolactone)] triblock copolymers

BACKGROUND: Biodegradable block copolymers have attracted particular attention in both fundamental and applied research because of their unique chain architecture, biodegradability and biocompatibility. Hence, biodegradable poly[((R )‐3 ‐hydroxybutyrate)‐block‐(D ,L ‐lactide)‐block‐(ε‐caprolactone)] (PHB‐PLA‐PCL) triblock copolymers were synthesized, characterized and evaluated for their biocompatibility. RESULTS: The results from nuclear magnetic resonance spectroscopy, gel permeation chromatography and thermogravimetric analysis showed that the novel triblock copolymers were successfully synthesized. Differential scanning calorimetry and wide‐angle X‐ray diffraction showed that the crystallinity of PHB in the copolymers decreased compared with methyl‐PHB (LMPHB) oligomer precursor. Blood compatibility experiments showed that the blood coagulation time became longer accompanied by a reduced number of platelets adhering to films of the copolymers with decreasing PHB content in the triblocks. Murine osteoblast MC3T3‐E1 cells cultured on the triblock copolymer films spread and proliferated significantly better compared with their growth on homopolymers of PHB, PLA and PCL, respectively. CONCLUSION: For the first time, PHB‐PLA‐PCL triblock copolymers were synthesized using low molecular weight LMPHB oligomer as the macroinitiator through ring‐opening polymerization with D ,L ‐lactide and ε‐caprolactone. The triblock copolymers exhibited flexible properties with good biocompatibility; they could be developed into promising biomedical materials for in vivo applications. Copyright © 2008 Society of Chemical Industry     

AB,BAB and (AB)3 poly(ε‐caprolactone)‐based block copolymers with functionalized poly(meth)acrylate segments

Linear and star‐shaped poly(ε‐caprolactone) (PCL) block copolymers containing poly(meth)acrylate segments with glycidyl, 2‐(trimethylsilyloxy)ethyl and tert‐butyl pendant groups were synthesized using mono‐, di‐ and trifunctional PCL macroinitiators and appropriate (meth)acrylate monomers by controlled radical polymerization. The well‐defined structures with narrow molecular weight distributions indicate the coexistence of semi‐crystalline PCL and amorphous poly(meth)acrylic phases. The hydrophobic nature of the block copolymers can be easily converted to amphiphilic, which with biodegradable and biocompatible PCL segments are promising as polymeric carriers in drug delivery systems. © 2012 Society of Chemical Industry     

Transesterification in homogeneous poly(ε‐caprolactone)–epoxy blends

Transesterification has been investigated in poly(ε‐caprolactone) (PCL)–epoxy blends. In the hot melt process, the hydroxyl on diglycidyl ether of bisphenol‐A (DGEBA) monomers is too low to give a noticeable transesterification reaction. In the postcure process, model reactions reveal that the hydroxyls from a ring‐opening reaction are able to react with the esters of PCL. In the meantime, the PCL molecular weight decrease and its distribution becomes broader. Nuclear magnetic resonance spectra reveal that fraction of the tertiary hydroxyls converts to secondary hydroxyls. In the cured DGEBA–3,3′‐dimethylmethylene‐di(cyclohexylamine)–PCL blend, a homogeneous morphology is achieved. PCL segments are grafted onto the epoxy network after postcuring and result in the lower T_g observed in the differential scanning calorimetry thermogram. A higher transesterification extent also results in broader transition peaks by dynamic mechanical analysis. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 75–82, 1999     

Surface chemical analysis of poly(ε‐caprolactone)–perfluoropolyether–poly(ε‐caprolactone) triblock copolymers by X‐ray photoelectron spectroscopy

The air‐side surface composition of a series of poly(ε‐caprolactone)–perfluoropolyether–poly(ε‐caprolactone) triblock copolymers with different compositions and block lengths have been studied by angle‐dependent X‐ray photoelectron spectroscopy (XPS). The weight percentage of the perfluoropolyether (PFPE) and polycaprolactone (PCL) blocks, and ethylene oxide linker (R_H) has been calculated in different ways: from C1s, O1s and F1s photoemission peaks and by line fitting of the C1s and O1s envelopes. The atomic sensitivity factors and the parameters used to fit the peak envelopes have been experimentally determined using some reference materials. A critical discussion of the different methods used in the surface characterization and the degradation of PFPE segments, induced by irradiation beam, have been also reported. A large excess of PFPE with respect to the bulk composition was observed in all samples, and the angular dependence of the XPS signal demonstrated that the content of the fluorinated block segment increased by decreasing the sampling depth. The PFPE surface concentration was also decreased by increasing the PCL/PFPE ratio, but the surfaces of the samples were still dominated by PFPE segments for copolymers with a bulk PFPE composition lower than 10%. Moreover, copolymers with similar PCL/PFPE bulk ratios but with different PFPE block lengths, showed similar PFPE surface composition when the number‐average molecular weight (M_n) was 2000 and 3200 g mol^?1, while that observed for copolymers containing PFPE block with M_n 900 g mol^?1 was lower. Copyright © 2003 Society of Chemical Industry     

Copolymers based on poly(butylene terephthalate) and polycaprolactone‐block‐polydimethylsiloxane‐block‐polycaprolactone

A series of novel thermoplastic elastomers, based on poly(butylene terephthalate) (PBT) and polycaprolactone‐block‐polydimethylsiloxane‐block‐polycaprolactone (PCL‐PDMS‐PCL), with various mass fractions, were synthesized through melt polycondensation. In the synthesis of the poly(ester‐siloxane)s, the PCL blocks served as a compatibilizer for the non‐polar PDMS blocks and the polar comonomers dimethyl terephthalate and 1,4‐butanediol. The introduction of PCL‐PDMS‐PCL soft segments resulted in an improvement of the miscibility of the reaction mixture and therefore in higher molecular weight polymers. The content of hard PBT segments in the polymer chains was varied from 10 to 80 mass%. The degree of crystallinity of the poly(ester‐siloxane)s was determined using differential scanning calorimetry and wide‐angle X‐ray scattering. The introduction of PCL‐PDMS‐PCL soft segments into the polymer main chains reduced the crystallinity of the hard segments and altered related properties such as melting temperature and storage modulus, and also modified the surface properties. The thermal stability of the poly(ester‐siloxane)s was higher than that of the PBT homopolymer. The inclusion of the siloxane prepolymer with terminal PCL into the macromolecular chains increased the molecular weight of the copolymers, the homogeneity of the samples in terms of composition and structure and the thermal stability. It also resulted in mechanical properties which could be tailored. Copyright © 2010 Society of Chemical Industry     

Synthesis,characterization, and hydrolytic degradation of biodegradable poly(ether ester)‐urethane copolymers based on ε‐caprolactone and poly(ethylene glycol)

In this article, a new kind of biodegradable poly(ε‐caprolactone)‐poly(ethylene glycol)‐poly(ε‐caprolactone)‐based polyurethane (PCEC‐U) copolymers were successfully synthesized by melt‐polycondensation method from ε‐caprolactone (ε‐CL), poly(ethylene glycol) (PEG), 1,4‐butanediol (BD), and isophorone diisocyanate (IPDI). The obtained copolymers were characterized by ¹H‐nuclear magnetic resonance (¹H‐NMR), FTIR, and gel permeation chromatography (GPC). Thermal properties of PCEC‐U copolymers were studied by DSC and TGA/DTG under nitrogen atmosphere. Water absorption and hydrolytic degradation behavior of these copolymers were also investigated. Hydrolytic degradation behavior was studied by weight loss method. ¹H‐NMR and GPC were also used to characterize the hydrolytic degradation behavior of PCEC‐U copolymers. The molecular weight of PCL block and PEG block in soft segment and the content of hard segment strongly affected the water absorption and hydrolytic degradation behavior of PCEC‐U copolymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of amphiphilic hydroxypropylcellulose‐graft‐poly(ε‐caprolactone)

An amphiphilic graft copolymer, hydroxypropylcellulose‐graft‐poly(ε‐caprolactone) (HPC‐g‐PCL), was synthesized by bulk polymerization without a catalyst and characterized with one‐dimensional and two‐dimensional NMR spectroscopy. Molar substitution of ε‐caprolactone on HPC (MS_CL) was estimated by both gravimetry and ¹H‐NMR, and the gravimetric method was considered suitable for MS_CL determination. Heterogeneity in the HPC‐g‐PCL film was suggested by a microscopic study, and the existence of PCL‐rich crystalline regions was confirmed by the results of X‐ray diffraction and differential scanning calorimetry (DSC). The double endotherm observed in the DSC scans of HPC‐g‐PCL was associated with the different molecular weight fractions in the copolymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 718–727, 2003     

Synthesis and characterization of poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers by combined ring‐opening polymerization and cross‐coupling processes

2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene was used as initiator in ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate (Sn(Oct)₂) catalyst. The resulting poly(ε‐caprolactone) (PCL) macromonomer, with a central 2,5‐dibromo‐1,4‐diphenylene group, was used in combination with 1,4‐dibromo‐2,5‐dimethylbenzene for a Suzuki coupling in the presence of Pd(PPh₃)₄ as catalyst or using the system NiCl₂/bpy/PPh₃/Zn for a Yamamoto‐type polymerization. The poly(p‐phenylenes) (PPP) obtained, with PCL side chains, have solubility properties similar to those of the starting macromonomer, ie soluble in common organic solvents at room temperature. The new polymers were characterized by ¹H and ¹³C NMR and UV spectroscopy and also by GPC measurements. The thermal behaviour of the precursor PCL macromonomer and the final poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry analyses and compared. Copyright © 2004 Society of Chemical Industry     

Effect of thermal aging on the biodegradation of PCL,PHB‐V,and their blends with starch in soil compost

Different proportions of starch were blended with poly(β‐hydroxybutyrate)‐co‐poly(β‐hydroxyvalerate) (PHB‐V) or poly(ε‐caprolactone) (PCL) by extrusion, and the mechanical (maximum tensile strength, elongation at break and Young's modulus) and thermal properties (by differential scanning calorimetry) were determined. The biodegradability of the blends in soil compost was also assessed after thermal aging for 192, 425, and 600 h at different temperatures. The maximum tensile strength of the PCL50 blend (containing 50% starch) was 35% lower than that of PCL and that of the PHB‐V50 blend was 60% lower than that of PHB‐V without thermal aging. PHB‐V blends were more biodegradable than PCL blends. For the blends prepared, only the biodegradation of PHB‐V25 was affected by thermal aging. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3539–3546, 2003     

Environmental degradation of biodegradable polyesters. IV. The effects of pores and surface hydrophilicity on the biodegradation of poly(ϵ‐caprolactone) and poly[(R)‐3‐hydroxybutyrate] films in controlled seawater

Poly(?‐caprolactone) (PCL) and poly[(R)‐3‐hydroxybutyrate] (R‐PHB) films with pores and hydrophilic surfaces were prepared by the water extraction of poly(ethylene oxide) from as‐cast blend films (1:1) and by the alkali treatment of as‐cast nonporous films, respectively. These films, as well as as‐cast nonporous PCL and R‐PHB films, were biodegraded in static seawater kept at 25°C, and their biodegradation was monitored with gravimetry, gel permeation chromatography (GPC), and scanning electron microscopy. The pores or highly hydrophilic surfaces of the PCL and R‐PHB films enhanced their biodegradation in seawater. Moreover, GPC measurements could be used to trace the biodegradation in seawater when the biodegradation proceeded to a great extent. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 587–593, 2003     

Crystallization and melting behavior of poly(ε‐caprolactone‐co‐δ‐valerolactone) and poly(ε‐caprolactone‐co‐L‐lactide) copolymers with novel chain microstructures

Nuclear magnetic resonance spectroscopy (NMR) characterization of the statistical copolymers of this study showed that the poly(ε‐caprolactone‐co‐L‐lactide)s, with ε‐caprolactone (ε‐CL) molar contents ranging from 70 to 94% and ε‐CL average sequence length (l_CL) between 2.20–9.52, and the poly(ε‐caprolactone‐co‐δ‐valerolactone)s, with 60 to 85% of ε‐CL and l_CL between 2.65–6.08, present semi‐alternating (R→2) and random (R～1) distribution of sequences, respectively. These syntheses were carried out with the aim of reducing the crystallinity of poly(ε‐caprolactone) (PCL), needed to provide mechanical strength to the material but also responsible for its slow degradation rate. However, this was not achieved in the case of the ε‐caprolactone‐co‐δ‐valerolactone (ε‐CL‐co‐δ‐VAL). Non‐isothermal cooling treatments at different rates and isothermal crystallizations (at 5, 10, 21 and 37°C) were conducted by differential scanning calorimetry (DSC), and demonstrated that ε‐CL copolymers containing δ‐valerolactone (δ‐VAL) exhibited a larger crystallization capability than those of L‐lactide (L‐LA) and also arranged into crystalline structures over shorter times. The crystallization enthalpies of the ε‐CL‐co‐δ‐VAL copolymers during the cooling treatments and their heat of fusion (ΔH_m) at the different isothermal temperatures were very large (i.e. ΔH_c > 53 Jg^?1) and in some cases, unrelated to the copolymer composition. In some compositions, such as the 60 : 40, Wide Angle X‐ray Scattering (WAXS) proved that that these two lactones undergo isomorphism and co‐crystallize in a single cell. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42534.     

Preparation and characterization of electrospun poly(ε‐caprolactone)–pluronic–poly(ε‐caprolactone)‐based polyurethane nanofibers

In this study, amphiphilic poly(ε‐caprolactone)–pluronic–poly(ε‐caprolactone) (PCL–pluronic–PCL, PCFC) copolymers were synthesized by ring‐opening copolymerization and then reacted with isophorone diisocyanate to form polyurethane (PU) copolymers. The molecular weight of the PU copolymers was measured by gel permeation chromatography, and the chemical structure was analyzed by ¹H‐nuclear magnetic resonance and Fourier transform infrared spectra. Then, the PU copolymers were processed into fibrous scaffolds by the electrospinning technology. The morphology, surface wettability, mechanical strength, and cytotoxicity of the obtained PU fibrous mats were investigated by scanning electron microscopy, water contact angle analysis, tensile test, and MTT analysis. The results show that the molecular weights of PCFC and PU copolymers significantly affected the physicochemical properties of electrospun PU nanofibers. Moreover, their good in vitro biocompatibility showed that the as‐prepared PU nanofibers have great potential for applications in tissue engineering. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43643.     

Thermo‐responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico‐chemical and mechanical properties

In this work, we present the synthesis and characterization of chemically crosslinked polyurethanes (PU) composed of poly(ethylene glycol) (PEG) and poly(caprolactone) diol (PCL‐diol), as hydrophilic and hydrophobic segments respectively, poly(caprolactone) triol (PCL‐triol), to induce hydrolysable crosslinks, and hexamethylene diisocyanate (HDI). The syntheses were performed at 45 °C, resulting in polyurethanes with different PEG/PCL‐diol/PCL‐triol mass fractions. All the PUs are able to crystallize and their thermal properties depend on the global composition. The water uptake capacities of the PU increase as the PEG amount increases. The water into hydrogels is present in different environments, as bounded, bulk and free water. The PU hydrogels are thermo‐responsive, presenting a negative dependence of the water uptake with the temperature for PEG rich networks, which gradually changes to a positive behavior as the amount of poly(caprolactone) (PCL) segments increases. However, the water uptake capacity changes continuously without an abrupt transition. Scanning electron microscopy (SEM) analyses of the hydrogel morphology after lyophilization revealed a porous structure. Mechanical compression tests revealed that the hydrogels present good resilience and low recovery hysteresis when they are subject to cycles of compression–decompression. In addition, the mechanical properties of the hydrogels varies with the composition and crosslinking density, and therefore with the water uptake capacity. The PU properties can be tuned to fit for different applications, such as biomedical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43573.     

Nanocomposites based on poly(ϵ‐caprolactone) and the montmorillonite treated with dibutylamine‐terminated ϵ‐caprolactone oligomer

Dibutylamine‐terminated ε‐caprolactone oligomers (CLOs: CLOL, CLOM, and CLOH) with number–averaged molecular weight (M_n), 500, 1300, and 2200, respectively, were synthesized by the ring‐opening polymerization of ε‐caprolactone initiated by 2‐(dibutylamino)ethanol in the presence of tin(II) 2‐ethylhexanoate. Nanocomposites based on poly(ε‐caploractone) (PCL) and the caprolactone oligomer‐treated montmorillonites (CLO‐Ms: CLOL‐M, CLOM‐M, and CLOH‐M) were prepared by melt intercalation method. The XRD and TEM analyses of the PCL composites revealed that the extent of exfoliation of the clay platelets increased with increasing molecular weight of the used CLOs. Tensile strength and modulus of the PCL/CLO‐M composites increased with increasing molecular weight of the CLO and increasing inorganic content. The tensile modulus of the PCL/CLOH‐M nanocomposite with inorganic content 5.0 wt % was three times higher than that of control PCL. Among the PCL/CLO‐M composites, the PCL/CLOM‐M composite had the highest crystallization temperature and melting temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Novel biodegradable amphiphilic poly(ε‐caprolactone)/poly(N‐vinylpyrrolidone) blends via successive in situ polymerizations

In this study, biodegradable blends of poly(ε‐caprolactone) (PCL) and poly(N‐vinylpyrrolidone) (PVP) were prepared by a new strategy in the following steps: (1) free radical polymerization of N‐vinyl‐2‐pyrrolidone (NVP) in ε‐caprolactone (CL); (2) ring‐opening polymerization of ε‐caprolactone in the presence of PVP to obtain the target blends. The structure of the blends was confirmed by FTIR and ¹H NMR, and the molecular weight of PCL and PVP were determined by GPC. SEM study revealed that this polymerization method could decrease the disperse phase size and improve the interphase when compared with solution‐blending method. The phase inversion occurred when PVP content was 15–20 wt %. Subsequently, the PCL sphere dispersed in PVP matrix and its size decreased with the increase of PVP content. The contact angle results showed that PVP has a profound effect on hydrophilic properties of PCL/PVP blends. PCL/PVP blends are believed to be promising for drug delivery, cell therapy, and other biomedical applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of star‐shaped poly(ε‐caprolactone)‐b‐poly(L‐lactide) copolymers: From star architectures to crystalline morphologies

Hexa‐armed star‐shaped poly(ε‐caprolactone)‐block‐poly(L ‐lactide) (6sPCL‐b‐PLLA) with dipentaerythritol core were synthesized by a two‐step ring‐opening polymerization. GPC and ¹H NMR data demonstrate that the polymerization courses are under control. The molecular weight of 6sPCLs and 6sPCL‐b‐PLLAs increases with increasing molar ratio of monomer to initiator, and the molecular weight distribution is in the range of 1.03–1.10. The investigation of the melting and crystallization demonstrated that the values of crystallization temperature (T_c), melting temperature (T_m), and the degree of crystallinity (X_c) of PLLA blocks are increased with the chain length increase of PLLA in the 6sPCL‐b‐PLLA copolymers. On the contrary, the crystallization of PCL blocks dominates when the chain length of PLLA is too short. According to the results of polarized optical micrographs, both the spherulitic growth rate (G) and the spherulitic morphology are affected by the macromolecular architecture and the length of the block chains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010