**3.2.1 Modification of vinyl and acryl polymers by CFPS**

The graft copolymers of polysiloxane with styrene, methyl metacrylate, and chloroprene were synthesized by a radical polymerization from the commercial carbofunctional polysiloxanes containing side and terminal mercaptopropyl groups (Fawcett et al., 2001).

#### **3.2.1.1 Polystyrene**

164 Thermoplastic Elastomers

Si-CH=CH2 + H-Si Si-CH2-CH2-Si Polypropylene containing terminal double bonds was modied with a hydride-terminated polydimethylsiloxane (PDMS) at three different temperatures through a hydrosilylation reaction, catalyzed by Karstedt's platinum catalyst in the melt phase (Malz & Tzoganakis, 1998; Long et al., 2003, 2004). The double bonds were formed by peroxide initiated degradation of PP in an extruder or a batch mixer. An organic peroxide, Lupersol 101, was used in concentrations of 0.5-5 wt. %. A hydride-terminated polydimethylsiloxane was used as a substrate hydrosilylating the terminal double bonds of the degraded polypropylene (DPP). Reactive processing experiments were carried out in a hot press, a batch mixer, and a single screw extruder. The reaction time of the hydrosilylation reaction was short enough to be completed in a screw extruder. This made possible the simultaneous extrusion and

Two different reaction mechanisms were used to initiate the hydrosilylation reaction: a radical chain addition mechanism and a platinum catalyzed mechanism using platinum Karstedt's catalyst. It was found that both reactions, degradation and hydrosilylation, could be performed simultaneously, by using high peroxide concentrations, while previously degraded polypropylene could be hydrosilylated with catalytic amounts of a peroxide. For the catalytic mechanism, the required stabilization of the platinum colloid formed in this

The hydrosilylation of polybutadiene (PB) with hydrosilanes is catalyzed by rhodium and platinum catalysts, and platinum-nanoclusters and it is a source of silyl derivatives of PB, many of them have functional group and can find useful applications (Guo et al., 1990; Iraqi

A comprehensive study on the surface characteristics of hydrosilylated polypropylene was conducted by combining macroscopic thermodynamics, microstructure, and chemical composition measurements (Long et al., 2003, 2004). A positive effect of a poly(dimethylsiloxane) modied polyolen additive on the processing and surface properties of linear low density polyethylene (LLDPE) was observed (Zhu et al., 2007). A polydimethylsiloxane (PDMS) modied polyolen, obtained by reacting an ethylene-ethyl acrylate-maleic anhydride (EEAMA) copolymer with an amine terminated PDMS in the melt phase, was used as a processing aid to facilitate the extrusion of LLDPE. Surface properties of hydrosilylated polyolens could be further modified by annealing in supercritical carbon dioxide (Zhu & Tzoganakis, 2008). Two hydrosilylated polypropylenes (PP) and polyethylenes (PE) were obtained by reacting with di- and multi-functional hydride terminated poly(dimethylsiloxane). Processing properties of polypropylene were improved by the addition of a small

A PDMS grafted copolymer, which can be potentially applied as a processing agent or a surface property modier, was synthesized via reactive melt mixing of ethylene–ethyl acrylate–maleic anhydride terpolymer (EEAMA) and aminopropyl terminated PDMS

Crosslinked styrene-isoprene-siloxane copolymers were applied for a preparation of membranes useful for pervaporative removal of volatile organic compounds from water.

mechanism was accomplished by adding *t*-butylhydroperoxide as a co-catalyst.

et al., 1992; Chauhan & Balagam, 2006; Chauhan et al., 2008).

amount (~2 wt. %) of silicone oil (Zhang et al., 2010).

(McManus et al., 2006).

modification of polypropylene.

Block copolymers comprised of chemically distinct polymers covalently joined together selforganize in bulk into well-defined nanoscopic structures including lamellar, cylindrical, and spherical morphologies. There are a lot of block copolymers based on styrene monomers with reactive alkoxysilyl groups. A series of well-defined poly(3-methacryloxypropyltriethoxysilane)-*b*–polystyrene (PMAPTES-*b*-PS) diblock copolymers was prepared via sequential RAFT polymerization (Zhang et al., 2007). Poly(acryloxypropyltriethoxysilane)-*b*polystyrene (PATPES-*b*-PS) diblock copolymers were prepared by the nitroxide-mediated polymerization (NMP) using alkoxyamine initiators (Gamys et al. 2010). The core-shell particles prepared by emulsion polymerization of styrene and subsequent addition of MPTMS have been used to produce hybrid nanocapsules (Ni et al., 2008). A series of welldefined rod-coil block copolymers poly(dimethylsiloxane-*b*-poly{2,5-bis[(4-methoxyphenyl) oxycarbonyl]styrene} (PDMS-*b*-PMPCS) containing a CO2-philic block PDMS was synthesized through ATRP (Shi et al., 2011). The nanostructure of these copolymers changed from lamellae (LAM) to hexagonally packed cylinders (HEX) according to the volume fraction of PDMS in block copolymers. The microemulsion photocopolymerization of styrene and butyl acrylate in the presence of silane coupling agent, such as MAPTMS, using 2-hydroxy-2-methylpropiophenone as photoinitiator was carried out as well (Wan et al., 2009). The copolymer particles were nearly spherical and were very uniform with the number average particle size of 25.5 nm and Mw/Mn of 1.11.

Modification of Thermoplastics with Reactive Silanes and Siloxanes 167

copolymerization of fluorinated monomers bearing an ω-trialkoxysilane function with vinylidene fluoride (VDF), were successfully cross-linked in the presence of moisture and these cross-linked materials showed interesting repellent properties with respect to boiling

Some silyl derivatives of polymers such as acrylates, methacrylates show membrane properties with the selectivity with reference to oxygen. Thus silyl methacrylate may be used in contact lenses. The synthesis of 2-hydroxyethyl methacrylate (HEMA) polymers modified with some silyl groups was carried out. The increase of polymethacrylates solubilities with increase of incorporation of silyl groups was observed (Assadi et al., 2005). Polymerization strategies to overcome limiting monomer conversion in silicone-acrylic miniemulsion polymerization were presented (Rodriguez et al., 2008). The waterborne silicone-modified acrylic materials were obtained from divinyl terminated PDMS and

Thermoresponsive shape memory polymers (SMPs) are the most studied materials because of their potential applications in biomedical fields. Poly(N-isopropylacrylamide) (PNIPAAm) is a typical example that exhibits a lower critical solution temperature (LCST) at ca. 32 C in water solution. Below this temperature PNIPAAm chains are soluble due to the hydrogen bonding interactions between polymer chains and water molecules, whereas the phase separation occurs and the polymers precipitate from the solution when the temperature is above the LCST. A series of monodisperse microgel with different particle sizes and cross-linking density were prepared by precipitation copolymerization of NIPAAm with 3-methacryloxypropyltriethoxysilane (MAPTES). The experimental results revealed that the microgel exhibited temperature sensitivity and the phase transition temperature approximately at 31 C. A decrease of MAPTES content resulted in a reduction

A self-assembly silane monolayer was formed by 3-aminopropyltriethoxysilane (APTES), followed by the graft polymerization of NIPAAm on the glass surface. These kind of glasses bonded with NIPAAm films have potential applications as environmentally switchable

PDMS have been widely used in a variety of biomedical applications, but their hydrophobicity is often a problem. This can be overcome with the introduction of hydrophilic polymers, such as poly(N,N-dimethylacrylamide) (PDMAAm). The synthesis of a new family of amphiphilic multiblock and triblock copolymers (PDMAAm-*b*-PDMS-b-PDMAAm) via RAFT polymerization was proposed (Pavlovic et al., 2008). A novel ABC triblock copolymer with very low surface energy: PDMS-*b*-PMMA-*b*-PHFBMA (2,2,3,3,4,4,4 heptafluorobutyl methacrylate) was successfully synthesized via ATRP by Luo et al. (2008). The lowest surface energy of these triblock copolymers reached 3.03 mN/m, thus the

A next interesting application of the CFPS is their utilization in synthesis of interpenetrating polymer networks (IPN) with fluorinated acrylates. These siloxane-fluoroacryl IPN networks were prepared *in situ* from of ,-(3-hydroxypropyl)polydimethylsiloxanes,

methyl methacrylate (MMA), butyl acrylate (BA), and acrylic acid (AA).

of the final hydrodynamic diameters of the microgel (Zhang et al., 2009).

PDMS-*b*-PMMA-*b*-PHFBMA could be applied as an antifouling coating.

acetone, water, acids, and oil (Guiot et al., 2006).

**3.2.1.4 Acryl polymers** 

materials (Wang et al., 2005).

Particles with structural and compositional anisotropy are great interest for potential applications such as optical switches and filters. Anisotropic particles are composed of various materials such as functional polymers and inorganic materials with a high refractive index. Nagao et al. (2008) demonstrated monodisperse, anisotropic particles composed of organic and inorganic materials, prepared in a two step soap-free emulsion polymerization. In the first step, seed polymer particles were prepared in the presence of MPTMS in water. In the second step, another polymerization of styrene and/or methyl methacrylate was conducted in the presence of seed particles, which induced anisotropic protrusion of polymer from the seed particles. This method is applicable to the preparation of anisotropic polymer particles containing inorganic particles such as silica.

The transparent hybrid materials were obtained by a bulk polymerization with styrene, ethylene glycol dimethacrylate (EGDMA), and silicone macromonomer containing PDMS chains with urethane and methacrylate functionalities (SiUMA) (Daimatsu et al., 2008). The prepared P(S-*co*-SiUMA-*co*-EDGMA) copolymers were transparent, similarly to pure PS, while P(S-*co*-SiUMA) copolymers were opaque.

The simple method for preparing block copolymers of PDMS and vinyl monomers was reported (Oz & Akar, 2006). PDMS-*b*-PAN and PDMS-*b*-PS copolymers were produced in one step with redox system of α,ω-dihydroxypropyl terminated PDMS/ceric ammonium nitrate at ambient temperature in water. The copolymer products had much higher contact angle values than corresponding homopolymers, although their silicone content was as low as 1-2 wt. %. These copolymers may act as compatibilizers in the blending application of vinyl polymers with polysiloxanes.

### **3.2.1.2 PVAL**

Silicone polyoxyalkylene copolymers are the most known silicone surfactants because of their biodegradability, biotolerance and water solubility, e.g. poly(vinyl alcohol)-*graft*-PDMS (Pouget et al., 2008). These copolymers have been synthesized in aqueous dispersion of a mono- or diepoxy terminated PDMS with pendant alcohols of P(VAL-*co*-VAC). The last copolymer was used as a dispersant to stabilize the PDMS microsuspension and the reaction took place at the interface of the silicone droplets. The preparation of PVAL-PDMS copolymers is of great interest, especially for the preparation of PVAL-PDMS amphiphilic copolymers. The incorporation of PDMS block in the PVAL structure would enhance its flexibility and resistance to moisture. Lacroix-Desmazes et al. (2008) reported synthesis of triblock copolymer PVAL-*b*-PDMS-*b*-PVAL.

#### **3.2.1.3 PVDF**

Poly(vinylidene fluoride) (PVDF), semicrystal membrane materials, were recently obtained. They showed high strength and good chemical resistance. However their relative hydrophobicity and inactivity have limited their use in materials for membrane separation of oil and biological molecules. For these applications the increase of PVDF hydrophilicity was necessary. PVDF as a macroinitiator was grafted with 3-methacrylate propyltrimethoxysilane (MAPTMS) via ATRP of MAPTMS. The flux of the membrane prepared from silylfuctionalized PVDF was much higher than that of the membrane prepared from parent material (Chen & Kim, 2008). Another limitations in application of PVDF are its poor solubility and difficulty in cross-linking. Low-molecular-weight copolymers obtained by copolymerization of fluorinated monomers bearing an ω-trialkoxysilane function with vinylidene fluoride (VDF), were successfully cross-linked in the presence of moisture and these cross-linked materials showed interesting repellent properties with respect to boiling acetone, water, acids, and oil (Guiot et al., 2006).

### **3.2.1.4 Acryl polymers**

166 Thermoplastic Elastomers

Particles with structural and compositional anisotropy are great interest for potential applications such as optical switches and filters. Anisotropic particles are composed of various materials such as functional polymers and inorganic materials with a high refractive index. Nagao et al. (2008) demonstrated monodisperse, anisotropic particles composed of organic and inorganic materials, prepared in a two step soap-free emulsion polymerization. In the first step, seed polymer particles were prepared in the presence of MPTMS in water. In the second step, another polymerization of styrene and/or methyl methacrylate was conducted in the presence of seed particles, which induced anisotropic protrusion of polymer from the seed particles. This method is applicable to the preparation of anisotropic

The transparent hybrid materials were obtained by a bulk polymerization with styrene, ethylene glycol dimethacrylate (EGDMA), and silicone macromonomer containing PDMS chains with urethane and methacrylate functionalities (SiUMA) (Daimatsu et al., 2008). The prepared P(S-*co*-SiUMA-*co*-EDGMA) copolymers were transparent, similarly to pure PS,

The simple method for preparing block copolymers of PDMS and vinyl monomers was reported (Oz & Akar, 2006). PDMS-*b*-PAN and PDMS-*b*-PS copolymers were produced in one step with redox system of α,ω-dihydroxypropyl terminated PDMS/ceric ammonium nitrate at ambient temperature in water. The copolymer products had much higher contact angle values than corresponding homopolymers, although their silicone content was as low as 1-2 wt. %. These copolymers may act as compatibilizers in the blending application of

Silicone polyoxyalkylene copolymers are the most known silicone surfactants because of their biodegradability, biotolerance and water solubility, e.g. poly(vinyl alcohol)-*graft*-PDMS (Pouget et al., 2008). These copolymers have been synthesized in aqueous dispersion of a mono- or diepoxy terminated PDMS with pendant alcohols of P(VAL-*co*-VAC). The last copolymer was used as a dispersant to stabilize the PDMS microsuspension and the reaction took place at the interface of the silicone droplets. The preparation of PVAL-PDMS copolymers is of great interest, especially for the preparation of PVAL-PDMS amphiphilic copolymers. The incorporation of PDMS block in the PVAL structure would enhance its flexibility and resistance to moisture. Lacroix-Desmazes et al. (2008) reported synthesis of

Poly(vinylidene fluoride) (PVDF), semicrystal membrane materials, were recently obtained. They showed high strength and good chemical resistance. However their relative hydrophobicity and inactivity have limited their use in materials for membrane separation of oil and biological molecules. For these applications the increase of PVDF hydrophilicity was necessary. PVDF as a macroinitiator was grafted with 3-methacrylate propyltrimethoxysilane (MAPTMS) via ATRP of MAPTMS. The flux of the membrane prepared from silylfuctionalized PVDF was much higher than that of the membrane prepared from parent material (Chen & Kim, 2008). Another limitations in application of PVDF are its poor solubility and difficulty in cross-linking. Low-molecular-weight copolymers obtained by

polymer particles containing inorganic particles such as silica.

while P(S-*co*-SiUMA) copolymers were opaque.

vinyl polymers with polysiloxanes.

triblock copolymer PVAL-*b*-PDMS-*b*-PVAL.

**3.2.1.2 PVAL** 

**3.2.1.3 PVDF** 

Some silyl derivatives of polymers such as acrylates, methacrylates show membrane properties with the selectivity with reference to oxygen. Thus silyl methacrylate may be used in contact lenses. The synthesis of 2-hydroxyethyl methacrylate (HEMA) polymers modified with some silyl groups was carried out. The increase of polymethacrylates solubilities with increase of incorporation of silyl groups was observed (Assadi et al., 2005).

Polymerization strategies to overcome limiting monomer conversion in silicone-acrylic miniemulsion polymerization were presented (Rodriguez et al., 2008). The waterborne silicone-modified acrylic materials were obtained from divinyl terminated PDMS and methyl methacrylate (MMA), butyl acrylate (BA), and acrylic acid (AA).

Thermoresponsive shape memory polymers (SMPs) are the most studied materials because of their potential applications in biomedical fields. Poly(N-isopropylacrylamide) (PNIPAAm) is a typical example that exhibits a lower critical solution temperature (LCST) at ca. 32 C in water solution. Below this temperature PNIPAAm chains are soluble due to the hydrogen bonding interactions between polymer chains and water molecules, whereas the phase separation occurs and the polymers precipitate from the solution when the temperature is above the LCST. A series of monodisperse microgel with different particle sizes and cross-linking density were prepared by precipitation copolymerization of NIPAAm with 3-methacryloxypropyltriethoxysilane (MAPTES). The experimental results revealed that the microgel exhibited temperature sensitivity and the phase transition temperature approximately at 31 C. A decrease of MAPTES content resulted in a reduction of the final hydrodynamic diameters of the microgel (Zhang et al., 2009).

A self-assembly silane monolayer was formed by 3-aminopropyltriethoxysilane (APTES), followed by the graft polymerization of NIPAAm on the glass surface. These kind of glasses bonded with NIPAAm films have potential applications as environmentally switchable materials (Wang et al., 2005).

PDMS have been widely used in a variety of biomedical applications, but their hydrophobicity is often a problem. This can be overcome with the introduction of hydrophilic polymers, such as poly(N,N-dimethylacrylamide) (PDMAAm). The synthesis of a new family of amphiphilic multiblock and triblock copolymers (PDMAAm-*b*-PDMS-b-PDMAAm) via RAFT polymerization was proposed (Pavlovic et al., 2008). A novel ABC triblock copolymer with very low surface energy: PDMS-*b*-PMMA-*b*-PHFBMA (2,2,3,3,4,4,4 heptafluorobutyl methacrylate) was successfully synthesized via ATRP by Luo et al. (2008). The lowest surface energy of these triblock copolymers reached 3.03 mN/m, thus the PDMS-*b*-PMMA-*b*-PHFBMA could be applied as an antifouling coating.

A next interesting application of the CFPS is their utilization in synthesis of interpenetrating polymer networks (IPN) with fluorinated acrylates. These siloxane-fluoroacryl IPN networks were prepared *in situ* from of ,-(3-hydroxypropyl)polydimethylsiloxanes,

Modification of Thermoplastics with Reactive Silanes and Siloxanes 169

Thermoresponsive shape memory polymers (SMPs) are a class of materials that change shape upon exposure to heat. They are lightweight, easy to fabricate and may be biodegradable. Poly(-caprolactone) (PCL)-based SMPs have received much attention due to the biocompatibility, biodegrability, and elasticity of PCL. PCL is useful as a crystalline switching segment for SMPs as its Ttrans is a well-defined Tm in the range of 45-60 C with increasing Mn. Such Ttrans values are useful for *in vivo* deployment as well as other applications which require low heating. To modify properties of PCL-based SMPs, AB polymer networks have been prepared through incorporation of organic hard or soft segments. PDMS with extremely low Tg (-123 C) is a particularly effective soft segment candidate. Schoener et al. (2010) prepared organic-inorganic SMPs comprised of inorganic PDMS segments, terminated by aminopropyl groups, and organic PCL segments. The resulting SMP network exhibited excellent shape fixity and recovery. By changing the PDMS length, the thermal, mechanical, and surface

Carbon nanotubes (CNTs) are the ideal reinforcing agents for high-strength polymer composites because of their tremendous mechanical strength, their Young's modulus is ca. 1000 GPa and it is much higher than that of the conventional carbon fibres (200-800 GPa). For good reinforcement effect the surface of CNTs must be strongly bonded to the polymer matrix. Sidewall functionalization of CNTs, introduction mainly carboxylic groups, makes possible to chemically attach these nanofillers with polymers. Chen and Shimizu (2008) prepared the nanocomposites of poly(L-lactide) (PLLA) reinforced by aminopropylisooctyl POSS modified multi-wall nanotubes (MWNTs) (MWNT-*g*-POSS). They have observed the homogeneous dispersion of MWNTs throughout the PLLA MWNT-*g*-POSS composites without any aggregation. The fractial surface of the composites showed not only a uniform

Alongi et al. (2009) have reported the preparation of inorganic-organic hybrids made of POSS and polyamide 6 (PA 6) produced by melt mixing of the two components or by the *in situ* polymerization of -caprolactam in the presence of POSS. The last method did not result in any POSS self-aggregation in the polymer matrix, achieving a very fine cubic dispersion of nanometric dimensions. The nearly nano-sized aromatic polyamide particles with amino groups, known as poly(amino-amide) PAMAM, were prepared by Yoshioka (2009). They were modified with silane coupling agent, i.e. 3-glycidoxypropyltriethoxysilane (GPTES), and further complexed with ZnO particles. The finally ZnO-based materials have specific optical properties: they show excellent optical absorption properties in UV region and high

Polyimides (PIs) are well-known engineering plastics with excellent thermal, mechanical, dielectric, and optical properties. They also have good chemical resistance and high dimensional stability. However the main deficiency of aromatic polyimides is their insolubility in organic solvents and infusibility or extremely high glass transition temperature (Tg) which makes their processing very difficult. One approach to increase the solubility and processability of polyimides is the introduction of flexible linkages or bulky units into the polymer chain. The incorporation of PDMS sequences in PIs has afforded new copolymers with good processability, low water absorption, atomic oxygen resistance, and excellent

dispersion of MWNTs but also a strong interfacial adhesion with the matrix.

properties were systematically alternated.

**3.2.2.2 Polyamides** 

**3.2.2.3 Polyimides** 

transmittance in the visible region.

isocyanurate derivatives of hexamethylene diisocyanates R(NCO)x, 3,3,4,4,5,5,6,6,7,7,8,8,8 tridecafluoro-1-octanol, ethylene glycol dimethacrylate (EGDMA), dicyclohexyl acrylate, and dipercarbonate (DCPD), towards dibutyltin dilaurate (DBTDL). A transparency of the obtained materials gave an evidence that no phase separation took place. The fluorinated polymers exhibit good hydro- and oleofobicity (Darras et al., 2007).
