Preparation and Properties of Water-Soluble PAA–PAS/SiO2 Hybrid Materials

Copolymers with different weight ratios of AA/PAS (acrylic acid/poly(DL-aspartic acid)) were synthesized and blended with sol-gel precursors to prepare water-soluble PAA–PAS/SiO₂ inorganic/organic hybrid materials. The PAS polymer or its copolymer in PAA–PAS/SiO₂ formed hydrogen bonds with SiO₂ and the amorphous structure of the hybrid material varied with the weight ratio of PAA. The hybrid materials exhibited enhanced thermal resistance over the copolymer alone. All hybrid materials were water-soluble and relatively insoluble in organic solvents.     

Phase compatibility and barrier properties of ethylene/vinyl alcohol copolymer based hybrid materials

An ethylene/vinyl alcohol copolymer (EVOH) with superior barrier properties was used as an organic component to prepare EVOH/SiO₂ hybrid materials with improved gas barrier properties with a sol–gel method. As a silane coupling agent, 3‐isocyanatopropyl triethoxysilane (IPTES) was used to promote interfacial attraction between the organic EVOH segments and the inorganic silicate network in the hybrid. The phase compatibility was evaluated by analysis of Fourier transform infrared spectroscopy and phase morphology and the optical properties of the hybrids. We confirmed that the addition of the silane coupling agent IPTES up to some level of content resulted in enhanced phase compatibility and optical transparency of the nanostructured hybrid material with a homogeneous phase morphology exhibiting no microphase separation. For the preparation of the monolayer coated film, the biaxially oriented polypropylene substrate pretreated with a corona was coated with the hybrid sols by a spin‐coating method. The oxygen permeation behavior through the coated film was examined with various contents of the silane coupling agent IPTES and inorganic silicate precursor tetraethoxyorthosilicate in the hybrid system. Consequently, it was revealed that an optimum range of IPTES and tetraethoxyorthosilicate contents was required to produce high barrier EVOH/SiO₂ hybrid materials with a stable homogeneous microstructure and enhanced optical transparency. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of 3‐aminopropyltriethoxysilane on properties of poly(butyl acrylate‐co‐maleic anhydride)/silica hybrid materials

The transparent poly(butyl acrylate‐co‐maleic anhydride)/silica [P(BA‐co‐MAn)/SiO₂] has been successfully prepared from butyl acrylate‐maleic anhydride copolymer P(BA‐co‐MAn) and tetraethoxysilane (TEOS) in the presence of 3‐aminopropyltriethoxysilane (APTES) by an in situ sol–gel process. Triethoxysilyl group can be readily incorporated into P(BA‐co‐MAn) as pendant side chains by the aminolysis of maleic anhydride unit of copolymer with APTES, and then organic polymer/silica hybrid materials with covalent bonds between two phases can be formed via the hydrolytic polycondensation of triethoxysilyl group‐functionalized polymer with TEOS. It was found that the amount of APTES could dramatically affect the gel time of sol–gel system, the sol fraction of resultant hybrid materials, and the thermal properties of hybrid materials obtained. The decomposition temperature of hybrid materials and the final residual weight of thermogravimetry of hybrid both increase with the increasing of APTES. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the morphology of hybrid materials prepared in the presence of APTES was a co‐continual phase structure. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 419–424, 1999     

Preparation of a Transparent Spherical Polymer Matrix Containing TiO2/SiO2 Hybrid Materials

A transparent spherical polymer matrix containing TiO₂/SiO₂ hybrid materials is prepared from the copolymerization reaction between TiO₂/SiO₂ hybrid materials containing vinyl groups and methyl methacrylate (MMA). Transparent TiO₂/SiO₂ hybrid materials are prepared from the reaction between nucleophilic agents and tetrabutyl titanate (TBT). Three reaction mechanisms leading to the formation of nanometer TiO₂/SiO₂ hybrid materials, including the single group coordination reaction mechanism (SGCRM), double group chelation reaction mechanism (DGCRM) and bridge coordination reaction mechanism (BCRM) are discussed in detail and confirmed by FT‐IR spectroscopy. The sizes of the TiO₂/SiO₂ hybrid material nanoparticles are also characterized and calculated by TEM and range from 20–40 nm. The diameter of the particles in the transparent spherical polymer matrix is ca. 100–200 nm and their shape is a regular spherical structure from TEM observations. The transparent spherical polymer matrix containing TiO₂/SiO₂ hybrid materials could be used as holographic anti‐counterfeiting materials.     

Synthesis and characterization of PMMA/SiO2 organic–inorganic hybrid materials via RAFT‐mediated miniemulsion polymerization

In this article, we first carried out the surface modification of SiO₂ using silane coupling agent KH570, and then prepared PMMA/SiO₂ organic–inorganic hybrid materials by conventional free radical polymerization and RAFT polymerization in miniemulsion, respectively. The kinetics comparisons of these two polymerizations were studied. PMMA/SiO₂ hybrid materials were characterized by gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis. Experimental results indicated that the polymerization behavior of MMA in miniemulsion showed controlled/living radical polymerization characteristics under the control of RAFT agent. Incorporation of RAFT agent and SiO₂ nanoparticles improved the thermal properties of polymers, the thermal stability of polymers increased with increasing content of SiO₂ nanoparticles. The structures and morphologies of SiO₂, modified SiO₂, and PMMA/SiO₂ hybrid materials were characterized by FT‐IR and TEM. TEM results showed that the addition of modified SiO₂ nanoparticles to miniemulsion polymerization system obtained different morphology latex particles. Most of modified SiO₂ nanoparticles were wrapped by polymer matrix after polymerization. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

Molecular dynamics simulation study on the structure and properties of polyimide/silica hybrid materials

A type of polyimide/silica (PI/SiO₂) copolymer model was established through the dehydration of tetraethyl orthosilicate molecules (TEOS) and bonding to a silane coupling agent. The content of SiO₂ was controlled by adjusting the number of molecules which bound to the TEOS. Finally, the silica was formed into a hybrid model (hybrid PI/SiO₂) with a small molecule embedded in the PI. The model was optimized by geometric and molecular dynamics and the changes in the model structure, Young's modulus, shear modulus, and glass-transition temperature (T _g) were analyzed. The results showed that the density and cohesive energy density of the composites could be improved by doping SiO₂ in PI. Young's modulus and shear modulus of PI/SiO₂ hybrid materials were higher than undoped PI. The tensile strength reached 568.15 MPa when the doping content was 9%. Therefore, the structure design and content control of SiO₂ was an effective way to improve the performance of a PI/SiO₂ composite. The variation of T _g and tensile strength of PI/SiO₂ hybrid composites is consistent with that of PI/SiO₂ composite synthesized in real experiment, which will be a convenient method for new material design and performance prediction. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47335.     

New fluorinated hybrid organic/inorganic water soluble polymeric network

This work presents the elaboration of nanoparticle networks from HASE (hydrophobically alkali-soluble emulsion) thickeners grafted with silica nanoparticles. Three HASE were realized by copolymerization in emulsion of methacrylic acid and ethyl acrylate or trifluoroethyl methacrylate and a hydrocarbon or fluorocarbon macromonomer. The macromonomer contains a hydrophobic pendant group separated from the backbone by a polyethylene glycol spacer chain. The free acid functions of the copolymer were coupled with amine functionalized silica nanoparticles. In basic aqueous solutions, the suspensions containing 1 wt.% of this polymer/SiO₂ nanocomposite characterized by DLS (size analysis) and Cryo-SEM are stable, translucent, and gel-like at pH = 7.5. Rheological measurements demonstrated that the grafting of silica nanoparticles did not affect the thickening effect of precursor co-polymers. Coating of glass plates was realized with these hybrid networks and characterized by AFM, indicating that the silica nanoparticles were more homogeneously dispersed when a fluorocarbon co-polymer was used.     

Preparation and application of fluorocarbon polymer/SiO2 hybrid materials,part 2: Water and oil repellent processing for cotton fabrics by sol–gel method

This research employed different procedures for out water and oil repellent finish on cotton fabrics with fluorocarbon copolymer or its hybrid materials. The experimental results indicated that fabrics processed with fluorocarbon copolymer have larger contact angle for water and oil repellent finish, and the fabric processed with simultaneous bathing of fluorocarbon copolymer/TEOS is the strongest but has poorer softness. Furthermore, when processing with chemical compounds, the processes or orders had little effect on the fabric's angle of contact and bleaching, but had more significant influence on strength. Regarding to washing fastness, after ten‐time water washing, the angle of contact of processed fabrics decreased by about 3%. Overall, the fabric pretreated with TEOS, followed by fluorocarbon polymer, had the best balance of physical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3019–3024, 2007     

Preparation of core–shell poly(acrylic acid)/polystyrene/SiO2 hybrid microspheres

Core–shell poly(acrylic acid)/polystyrene/SiO₂ (PAA/PS/SiO₂) hybrid microspheres were prepared by dispersion polymerization with three stages in ethanol and ethyl acetate mixture medium. Using vinyltriethoxysilane (VTEOS) as silane agent, functional silica particles structured vinyl groups on surfaces were prepared by hydrolysis and polycondensation of tetraethoxysilane and VTEOS in core stage. Then, the silica particles were used as seeds to copolymerize with styrene and acrylic acid sequentially in shell stage I and stage II to form PAA/PS/SiO₂ hybrid microspheres. Transmission electron microscope results show that most PAA/PS/SiO₂ hybrid microspheres are about 40 nm in diameter, and the silica cores are about 15 nm in diameter, which covered with a layer of PS about 7.5‐nm thick and a layer of PAA about 5‐nm thick. This core–shell structure is also conformed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and differential scanning calorimetry. FTIR results show that silica core, PS shell, and PAA outermost shell are bonded by covalents. In the core–shell PAA/PS/SiO₂ hybrid microsphere, the silica core is rigidity, and the PAA outermost shell is polarity, while the PS layer may work as lubricant owning to its superior processing rheological property in polymer blending. These core–shell PAA/PS/SiO₂ hybrid microspheres have potential as new materials for polar polymer modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1729–1733, 2006     

Preparation of polymer/silica/polymer tri-layer hybrid materials and the corresponding hollow polymer microspheres with movable cores

Tri-layer poly(methacrylic acid-co-ethyleneglycol dimethacrylate)/silica/poly(ethyleneglycol dimethacrylate) (P(MAA-co-EGDMA)/SiO₂/PEGDMA) and P(MAA-co-EGDMA)/SiO₂/polydivinylbenzene hybrid microspheres were prepared by distillation precipitation polymerization of ethyleneglycol dimethacrylate (EGDMA) and divinylbenzene (DVB) in the presence of 3-(methacryloxy)propyl trimethoxysilane (MPS)-modified P(MAA-co-EGDMA)/SiO₂ microspheres as the seeds. The polymerization of EGDMA and DVB was performed in neat acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as initiator to coat the MPS-modified P(MAA-co-EGDMA)/SiO₂ seeds through the capture of EGDMA and DVB oligomer radicals with the aid of vinyl groups on the surface of modified seeds in the absence of any stabilizer or surfactant. Monodisperse P(MAA-co-EGDMA)/SiO₂ core-shell microspheres were synthesized by coating of a layer of silica onto P(MAA-co-EGDMA) microspheres via a sol-gel process, which were further grafted by MPS incorporating the reactive vinyl groups onto the surface to be used as the seeds for the construction of hybrid microspheres with tri-layer structure. Hollow poly(ethyleneglycol dimethacrylate) (PEGDMA) and poly(divinylbenzene) (PDVB) microspheres with movable P(MAA-co-EGDMA) core were subsequently developed after the selective etching of the silica mid-layer from the tri-layer hybrid microspheres in hydrofluoric acid. The morphology and structure of the tri-layer polymer hybrids and the corresponding hollow polymer microspheres with movable P(MAA-co-EGDMA) core were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectra and X-ray photoelectron spectroscopy (XPS).     

Synthesis and characterization of novel ultraviolet‐curing polyurethane acrylate/epoxy acrylate/SiO2 hybrid materials via sol–gel reaction

A series of ultraviolet‐curable hybrid materials was first synthesized here by sol–gel process based on tetraethoxysilane (TEOS) and polyurethane acrylate/epoxy acrylate resin. The functional groups in the hybrid materials were investigated by infrared spectroscopy (IR) analysis. The crystallinity of the hybrid materials and polymer resin was examined by X‐ray diffraction. Then, nearly uniform dispersion of SiO₂ particles with the diameters ?100 nm were revealed by field emission scanning electron micrographs. The surface morphology was scanned by atomic force microscope. And, thermal stability was measured by thermogravimetric analysis for hybrid materials produced from different mass ratio of TEOS to polymer. The results show that the hybrid material from the mass ratio of TEOS to polymer of 0.4 : 1 performed desirable optimal thermal stability and uniform microstructure which is suitable for optical fiber coating in high temperature application. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Surface properties of poly(dimethylsiloxane)-based inorganic/organic hybrid materials

Poly(dimethylsiloxane) (PDMS)-based hybrid materials were prepared by the sol-gel method on Si wafers, Al and polystyrene (PS) substrates. The reaction was monitored by attenuated total reflectance-infrared (ATR-IR) spectroscopy. The hybrid materials have always one surface made in contact with air and one with a substrate. These surfaces were investigated by using tapping mode atomic force microscopy (AFM), X-ray photo-electron spectroscopy (XPS), low-energy ion scattering (LEIS) and dynamic contact angle (DCA) analysis. The hybrid sample surfaces made in contact with air and substrates appeared to have different structures. The former have a silica-free PDMS top layer of ∼2 nm thick; while in the latter cases, SiO₂ are located at or just beneath the outermost atomic layer. In air and at room temperature, SiO₂ are likely beneath the outermost atomic layer. In contact with water, polar -OH groups at the surface of SiO₂ can easily stretch out to the outermost atomic layer. No correlation was found between the roughness of the surfaces and the amount of in situ formed SiO₂ present in the materials.     

Preparation of siloxane–silsesquioxane hybrid thin films for large‐scale‐integration interlayer dielectrics with excellent mechanical properties and low dielectric constants

Several kinds of homogeneous organic–inorganic hybrid polymer thin films were designed with improved mechanical properties and low dielectric constants (<3.0). Novel soluble siloxane–silsesquioxane hybrid polymers were synthesized with cyclic and/or cage silane monomers, which had triorganosiloxy (R₃Si_1/2), diorganosiloxane (R₂SiO_2/2), and organosilsesquioxane (RSiO_3/2) moieties with ethylene bridges at the molecular level, by the hydrolysis and condensation of 2,4,6,8‐tetramethyl‐2,4,6,8‐tetra(trimethoxysilylethyl)cyclotetrasiloxane (a cyclic monomer). The electrical properties of these films, including the dielectric constant (～2.51), leakage current (6.4 × 10^?11 A/cm² at 0.5 MV/cm), and breakdown voltage (～5.4 MV/cm) were fairly good. Moreover, the mechanical properties of the hybrid films, including the hardness (～7 GPa), modulus (～1.2 GPa), and crack‐free thickness (<2 μm), were excellent in comparison with those of previous spin‐on‐glass materials with low dielectric constants. The excellent mechanical properties were proposed to be due to the high contents of Si? OH groups (>30%) and the existence of ethylene bridge and siloxane moieties in the hybrid polymer precursors. In addition, the mechanical properties of the hybrid films were affected by the contents of the cagelike structures. The more cagelike structures a hybrid film contained, the worse its mechanical properties were. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 626–634, 2003     

Study of poly(methyl methacrylate–maleic anhydride)/silica hybrid materials

Poly(methyl methacrylate–maleic anhydride) [P(MMA–MAn)] with active groups, anhydrides, was synthesized by radical copolymerization. Using P(MMA–MAn) as a basic polymer, the P(MMA–MAn)/SiO₂ hybrid materials were obtained by a sol–gel process in different ways. The structures of the materials were characterized by IR spectra, and their properties were studied by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and dynamic analysis (DA). The results show that the hybrids prepared in different ways have different properties, and the contents of SiO₂ also have influence on the properties of the hybrids. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 379–383, 2000     

One‐step synthesis of graphene nanoplatelets/SiO2 hybrid materials with excellent toughening performance

Graphene nanoplatelets (GNPs)/SiO₂ hybrid materials had been prepared successfully via chemical grafting in one step. Herein, SiO₂ particles and GNPs were connected by poly acryloyl chloride (PACl). The results from Fourier transform infrared spectroscopy showed that functionalized GNPs and SiO₂ particles had been successfully bridged with chemical bonds like O CO and Si O C. And the nanostructure of hybrid materials was characterized by scanning electron microscopy and transmission electron microscopy. All the images indicated that SiO₂ particles were grafted on the surface of GNPs successfully. Moreover, the result of Raman spectroscopy showed that carbon atoms of GNPs became much more disorder, due to destroying the carbon domains during the process of chemical drafting. Meaningfully, the results from tensile tests indicated that Graphene/SiO₂ hybrid materials had better toughening effect on epoxy composites than graphene oxide and SiO₂ particles. POLYM. COMPOS., 36:907–912, 2015. © 2014 Society of Plastics Engineers     

Crystallization behavior of PA66/SiO2 organic‐inorganic hybrid material

The poly 2‐hydroxy propylmethacrylate‐methyl methacrylate (PHPMA‐MMA)/SiO₂ composite, derived from 2‐hydroxy propylmethacrylate (HPMA), methyl methacrylate (MMA), and tetraethoxysilane (TEOS), was used to synthesize polyamide 66(PA66)/SiO₂ organic‐inorganic hybrid material. X‐ray diffraction (XRD) was used to investigate the lattice spacing change of the PA66/SiO₂ hybrid material. It was found that the addition of PHPMA‐MMA/SiO₂ composite nearly did not change the crystal form of PA66. The nonisothermal crystallization kinetics of PA66 and PA66/SiO₂ hybrid material was investigated by differential scanning calorimetry (DSC) with various cooling rates. At every given cooling rate, the start crystallization temperature of the PA66/SiO₂ hybrid material was higher than that of PA66, while the crystallization temperature range was narrower than that of PA66. Avrami analysis modified by the Jeziorny method, the Ozawa method, and a method developed by Liu were employed to describe the nonisothermal crystallization process of the samples. The results showed that the Jeziorny method and the Ozawa method were not suitable to describe the nonisothermal crystallization process of PA66/SiO₂ hybrid material; however, when the relative degree of crystallinity X (t) was less than 1 ? 1/e, ln [? ln (1 ? X (t))] was still linear to lnt. The Liu method was successful to describe the nonisothermal crystallization processes for both PA66 and the PA66/SiO₂ hybrid material. It was confirmed that the presence of PHPMA‐MMA/SiO₂ composite could increase the crystallization rate and had a hetero phase nucleation effect on the PA66 matrix. Moreover, the introduction of PHPMA‐MMA/SiO₂ could improve the crystallization active energy ?E calculated by the Kissinger equation, attributing to the strong interaction between the polyamide chains and the PHPMA‐MMA/SiO₂ composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 810–817, 2006     

Preparation of ellipsoidal hematite/polymer hybrid materials and the corresponding hollow polymer ellipsoids

Ellipsoidal hematite/poly(ethyleneglycol dimethacrylate) core-shell hybrid materials were prepared by distillation precipitation polymerization of ethyleneglycol dimethacrylate (EGDMA) in the presence of 3-(methacryloxy)propyl trimethoxysilane (MPS)-modified hematite (α-Fe₂O₃) particles as the seeds. The polymerization of EGDMA was performed in neat acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as initiator to coat MPS-modified hematite seeds through the capture of EGDMA oligomer radicals with the aid of vinyl groups on the surface of the MPS-modified hematite particles in absence of any stabilizer or surfactant. The shell-thickness of the core-shell hybrid particles was controlled by the feed of EGDMA monomer during the polymerization. Other hematite/polymer core-shell hybrid particles, such as hematite/polydivinylbenzene (α-Fe₂O₃/PDVB) and hematite/poly(divinylbenzene-co- methacrylic acid) (α-Fe₂O₃/P(DVB-co-MAA)) were also prepared by this procedure. Hematite/poly(N,N′-methylenebisacrylamide-co-methacrylic acid) (α-Fe₂O₃/P(MBAAm-co-MAA)) were synthesized with unmodified hematite particles as the seeds. Hollow polymer ellipsoids were subsequently developed after the selective removal of the hematite core with hydrochloric acid (HCl) from hematite/polymer core-shell hybrids. The resultant core-shell hybrid particles and hollow polymer ellipsoids were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and vibrating sample magnetometer (VSM).     

The situ preparation of silica nanoparticles on the surface of functionalized graphene nanoplatelets

A method for situ preparing a hybrid material consisting of silica nanoparticles (SiO₂) attached onto the surface of functionalized graphene nanoplatelets (f-GNPs) is proposed. Firstly, polyacrylic acid (PAA) was grafted to the surface of f-GNPs to increase reacting sites, and then 3-aminopropyltriethoxysilane (APTES) KH550 reacted with abovementioned product PAA-GNPs to obtain siloxane-GNPs, thus providing reaction sites for the growth of SiO₂ on the surface of GNPs. Finally, the SiO₂/graphene nanoplatelets (SiO₂/GNPs) hybrid material is obtained through introducing siloxane-GNPs into a solution of tetraethyl orthosilicate, ammonia and ethanol for hours'' reaction. The results from Fourier transform infrared spectroscopy (FTIR) showed that SiO₂ particles have situ grown on the surface of GNPs through chemical bonds as Si-O-Si. And the nanostructure of hybrid materials was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). All the images indicated that SiO₂ particles with similar sizes were grafted on the surface of graphene nanoplatelets successfully. And TEM images also showed the whole growth process of SiO₂ particles on the surface of graphene as time grows. Moreover, TGA traces suggested the SiO₂/GNPs hybrid material had stable thermal stability. And at 900°C, the residual weight fraction of polymer on siloxane-GNPs was about 94.2% and that of SiO₂ particles on hybrid materials was about 75.0%. However, the result of Raman spectroscopy showed that carbon atoms of graphene nanoplatelets became much more disordered, due to the destroyed carbon domains during the process of chemical drafting. Through orthogonal experiments, hybrid materials with various sizes of SiO₂ particles were prepared, thus achieving the particle sizes controllable. And the factors’ level of significance is as follows: the quantity of ammonia > the quantity of tetraethyl orthosilicate (TEOS) > the reaction time.     

Characterization and properties of UV‐curable polyurethane‐acrylate/silica hybrid materials prepared by the sol‐gel process

UV‐curable, transparent hybrid material of urethane‐acrylate resin was prepared by the sol‐gel process using 3‐(trimethoxysilyl)propylmethacrylate (TMSPM) as a coupling agent between the organic and inorganic phases. The effects of the content of acid and silica on the morphology and mechanical properties of UV‐curable polyurethane‐acrylate/silica hybrid (UA‐TMSPM)/SiO₂ materials have been studied. The results of thermogravimetric analysis for the (UA‐TMSPM)/SiO₂ hybrid materials indicated that the thermal stability of the hybrids is greatly improved. It was found that with the increase of HCl content, the interfacial interaction between organic and inorganic phases had been strengthened, as demonstrated by field emission scanning electron microscopy. Without sacrificing flexibility, the hybrid materials showed improved hardness with increasing content of acid and silica. Compared with the pure organic counterpart UA/hexanediol diacrylate (UA/HDDA) system, abrasion resistance of the hybrids improved with increasing acid content, at low silica content. Copyright © 2004 Society of Chemical Industry     

Preparation and characterization of POSS-crosslinked PCL based hybrid materials

PCL based hybrid films exhibiting heat-responsive shape memory properties had been obtained by using Heptaphenyltricycloheptasiloxane Trihydroxy Silanol (T7-OH) as a cross-linker. The crystallization behaviors of the materials were studied in detail by DSC and XRD. The thermal properties of the materials were detected through TGA. The static mechanical properties, in vitro degradation and shape memory properties were also studied systematically. There was no remarkable T7-OH crystal plane diffraction peak according to XRD which indicated that T7-OH was well dispersed in the matrix. Meanwhile, according to the TGA, thermal degradation temperatures were increased significantly when T7-OH were added. It was worth noting that the materials possessed excellent shape memory properties with R_f > 97 % and R_r > 97 %.