Abstract: A silane coating composition containing a silicon-based copolymer, a method for treating the surfaces of a metal such as steel, zinc-coated steels, or aluminum, to provide for the formation of a uniform conversion and/or passivation coating which increases the corrosion resistance of bare or painted metal and/or the adhesion properties of the metal, along with a metal having a conversion and/or passivation coating applied thereto are disclosed. Methods of the invention include contacting the requisite metal surface with an aqueous solution of a silane compound and a silicon-based polyether copolymer.

Abstract: An antifouling condensation curing organopolysiloxane composition is prepared by premixing a part or all of (A) a diorganopolysiloxane free of a reactive group with a part or all of (B) silica to form a premix, then mixing the premix with the remainder of (A) and (B), (C) a base diorganopolysiloxane, and (D) a silane. The composition has a good balance of low viscosity and high thixotropy, can be thickly coated in a single pass, and cures into a coating having rubber strength and surface smoothness and exhibiting satisfactory antifouling property over a long period of time.

Abstract: One aspect of the present invention includes a swellable sol-gel composition including a plurality of interconnected organosilica nanoparticles. Another aspect of the present invention includes a swellable composite including a plurality of interconnected organosilica nanoparticles and a particulate material capable of binding to or reacting with a non-polar or organic sorbate. When dried, the sol-gel composition and the swellable composite may be capable of swelling to at least twice their dried volume when placed in contact with a non-polar or organic sorbate.

Abstract: A silicon-containing film is formed from a heat curable composition comprising (A) a silicon-containing compound obtained by effecting hydrolytic condensation of a hydrolyzable silicon compound in the presence of an acid catalyst, and substantially removing the acid catalyst from the reaction mixture, (B) a hydroxide or organic acid salt of lithium, sodium, potassium, rubidium or cesium, or a sulfonium, iodonium or ammonium compound, (C) an organic acid, and (D) an organic solvent. The silicon-containing film allows an overlying photoresist film to be patterned effectively. The composition is effective in minimizing the occurrence of pattern defects after lithography and is shelf stable.

Abstract: The present invention relates to compositions, which are useful for the generation of patterned or structured SiO2-layers or of SiO2-lines during the manufacturing process of semiconductor devices, and which are suitable for the application in inkjet operations. The present invention also relates to a modified process of manufacturing semiconductor devices taking advantage of these new compositions.

Abstract: Disclosed is a process of preparing a moulded article, comprising 1) hydrolyzing a) at least one silane having one non-hydrolysable organic group, and b) at least one compound selected from b1) a silane having two non-hydrolysable organic groups, and b2) a hydrolysable polysiloxane, or a mixture thereof, and c) optionally at least one silane having no non-hydrolysable organic group, to prepare a composite composition comprising a hydrolysate or condensate, 2) placing the composite composition in a mould, 3) curing the composite composition to increase the degree of condensation, 4) removing the moulded article from the mould, and 5) heat treating the moulded article at a temperature of at least 100° C. The moulded article is preferably an optical lens which may be used for automobile headlights.

Abstract: Cross-linked sol-gel like materials and cross-linked aerogels, as well as methods for making such cross-linked sol-gel like materials and cross-linked aerogels are described.

Abstract: A coating material composite, comprising containing: a silane compound represented by the general formula (A); and an epoxy group-containing organic compound containing one or more epoxy groups in each molecule; wherein the silane compound has a content of 60 to 97% by weight relative to a total amount of resin components; and wherein the epoxy group-containing organic compound has a content of 3 to 10% by weight relative to the total amount of resin components; XmR13?mSi—Y—SiR13?mXm??(A) [R1 is a monovalent hydrocarbon group having a carbon number of 1 to 6; Y is a divalent organic group containing one or more fluorine atoms; X is a hydrolytic group; and m is an integer of 1 to 3]. The coating formed by such a coating material composite is capable of keeping a higher anticrack property even upon exposure to high-temperature.

Abstract: A silicone resin composition is provided comprising a silicon base polymer obtained from dehydration reaction of a silicon base monomer comprising at least 70 mol % of a hydrolyzable silane compound (A). The hydrolyzable silane compound (A) has at least a pair of silicon atoms linked by a linking group which is an aliphatic hydrocarbon group or an aromatic ring-containing hydrocarbon group, and having attached thereto at least three substituent groups selected from hydrogen, hydroxyl and hydrolyzable groups. A proportion of aromatic structure-containing substituent groups is up to 30 mol % of the entire silicon-bonded substituent groups. The composition is suited to form an optical material.

Abstract: Disclosed is a method for extracting metal particulates for an aqueous solution using a sol-gel derived sorbent.

Abstract: The present invention provides an organopolysilmethylene represented by the following general formula (1): wherein R1 is, independently of each other, a group selected from the group consisting of an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, a hydroxy group, R3SiCH2— and R3SiO—, wherein R is, independently of each other, a group selected from the group consisting of an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, and a hydroxy group, m is an integer of 1 to 100, and n is an integer of 1 to 100, and wherein at least two out of R1's and R's are an alkenyl group.

Abstract: Disclosed is a bishydroxyarylsiloxane compound. The bishydroxyarylsiloxane compound has a novel structure in which a particular moiety is introduced between siloxane blocks. Due to this structure, the physical properties of a copolymer of the bishydroxyarylsiloxane compound and a polymer can be tuned. Further disclosed is a method for preparing the bishydroxyarylsiloxane compound.

Abstract: Provided is a heat-conductive silicone composition, including: (A) 100 parts by volume of an organopolysiloxane having a specific structure, (B) 0.1 to 50 parts by volume of an organosilicon compound that functions as a wetter and contains a triorganooxysilyl group bonded to one terminal via an alkylene group that may be branched, (C) 100 to 2,500 parts by volume of a heat-conductive filler, and (D) an effective quantity of a curing agent. Also provided is a heat-conductive silicone cured product obtained by curing this composition. The heat-conductive silicone composition, even when filled with a large quantity of a heat-conductive filler in order to provide superior thermal conductivity, exhibits a minimal increase in viscosity or plasticity, and retains favorable handling properties and moldability. The heat-conductive silicone cured product exhibits excellent flexibility even when filled with a large quantity of a heat-conductive filler.

Abstract: The present invention relates to a method of making a swellable sol-gel composition that involves the use of a bridged silane precursor. The resulting sol-gel includes residual silanols, which are derivatized with a reagent having at least one silanol-reactive group and at least one alkyl group; and the sol-gel is then dried. Sol-gels of the invention are demonstrated to swell up to about 8-10 times their original volume in the presence of a non-polar sorbate. The sol-gel compositions can be used in a sorbate-activated actuator or in a detector for non-polar sorbates. The sol-gel compositions can further be used to take up non-polar sorbates for purposes of chemical remediation, extraction from aqueous systems or vapor, and chemical sensing.

Abstract: A multi-component room-temperature-curable silicone rubber composition comprising at least: (A) a diorganopolysiloxane, (B) a methoxy group-containing silicon compound comprising a bis(methoxysilyl)alkane or a organotrimethoxysilane (except amino group containing organotrimethoxysilane) (B-1), a methoxy group-containing carbasilatrane derivative (B-2), and an aminoalkylmethoxysilane (B-3) (wherein the weight ratio of constituent (B-2) to constituent (B-3) is in the range of (20:80) to (80:20)); and (C) a curing catalyst, the composition being packaged as two or more separately stored compositions wherein none of said separately stored compositions contain all said components (A), (B), and (C) simultaneously.

Abstract: Carbosilane-containing polymers (including oligomers) having the following structural features: greater than one repeat unit; at least four Si-arylene bonds; at least one (meth)acrylate moiety, Si—H moiety, or both; no Si—O bonds; preferably at least four silicon atoms; wherein two silicon atoms are separated by one arylene group in each repeat unit.

Abstract: The invention relates to silane cross-linking curable compositions, comprising a polymer P with at least two terminal groups of the following formulae (I) and (II) -Am-K1—SiXYZ (I), -Am-K2—SiXYZ (II), and/or two polymers P1 and P2, the polymer P1 having terminal groups of the following formula (I) -Am-K1—SiXYZ (I), and the polymer P2 having terminal groups of the following formula (II) -Am-K2—SiXYZ (II). In said formulae, A represents a bivalent binding group K1 and K2 independently of one another represent a bivalent aliphatic hydrocarbon group with a main chain of between 1 and 6 carbon atoms, the hydrocarbon groups K1, K2 being different, X, Y and Z independently of one another represent a hydroxy group of a hydrolysable group and m stands for 0 or 1.

Abstract: A novel multi-functional linear siloxane compound, a siloxane polymer prepared from the siloxane compound, and a process for forming a dielectric film by using the siloxane polymer. The linear siloxane polymer has enhanced mechanical properties (e.g., modulus), superior thermal stability, a low carbon content and a low hygroscopicity and is prepared by the homopolymerization of the linear siloxane compound or the copolymerization of the linear siloxane compound with another monomer. A dielectric film can be produced by heat-curing a coating solution containing the siloxane polymer which is highly reactive. The siloxane polymer prepared from the siloxane compound not only has satisfactory mechanical properties, thermal stability and crack resistance, but also exhibits a low hygroscopicity and excellent compatibility with pore-forming materials, which leads to a low dielectric constant.

Abstract: In one aspect, the invention relates to compositions comprising siloxanyl compounds comprising the structure: or residues thereof. Such compositions can be suitable for producing molded articles, can be excellent in transparency, hydrophilicity, and oxygen permeability, and can have a low modulus of elasticity and/or an excellent optical quality, so as to be suitable for ophthalmic lenses such as contact lenses and intraocular lenses. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Abstract: To provide a curable composition which has a high curing rate and can provide a cured product having good durability. A curable composition comprising an oxyalkylene polymer (A) having a reactive silicon group represented by the following formula (1), and a quaternary ammonium salt (B): —SiX1aR13-a??(1) wherein R1 is a C1-20 monovalent organic group which may have a substituent, X1 is a hydroxyl group or a hydrolyzable group, and a is an integer of from 1 to 3; provided that when plural R1s are present, they may be the same or different from one another, and when plural X1s are present, they may be the same or different from one another.

Abstract: Provision of a curable composition having good curability and adhesiveness by the use of a non-organotin catalyst. A curable composition containing an organic polymer (A) having a silicon-containing group crosslinkable by forming a siloxane bond, metal carboxylate (B), a silane coupling agent (C) free of an amino group, and an amino group-containing compound (D) in an amount corresponding to a weight ratio relative to (B) of 0-0.05, which contains, as the silicon-containing group of component (A), a silicon-containing group, wherein three hydrolyzable groups or hydroxyl groups are bonded to a silicon atom, as an essential component.

Abstract: A composition includes a copolymer including a mixture of monomeric units having structures (A), (B), and (C), and one or more of structures (D) or (E): HSiO(3-a)/2(OH)a??(A) Si(3-b)/2(OH)b—CH2)n—SiO(3-c)/2(OH)c??(B) R1SiO(3-d)/2(OH)d??(C) MeSi(3-e)/2(OH)e??(D) R2SiO(3-f)/2(OH)f??(E) wherein a, b, c, d, e, and f are independently from 0 to 2, n is from 0 to about 10, R1 is a chromophore, and R2 is a hydrophilic group.

Abstract: A perfluoropolyether-polyorganosiloxane copolymer comprising at least one perfluoropolyether block, at least one polyorganosiloxane block which may has a silalkylene group, and two monovalent groups represented by the following formula (1), each one at both ends of the copolymer, wherein X is a hydrolyzable group, R1 is an alkyl group having 1 to 4 carbon atoms or a phenyl group, y is an integer of from 1 to 5, and a is an integer of 2 or 3, said copolymer having a number average molecular weight, reduced to polystyrene, of from 7,000 to 25,000.

Abstract: A polycarbosilane has a main chain in which silicon atoms and carbon atoms are alternately repeated, and includes a structural unit shown by the following general formula (1), a structural unit shown by the following general formula (2), a structural unit shown by the following general formula (3), and a structural unit shown by the following general formula (4).

Abstract: The invention relates to ?-ethoxysilane modified polymers of the average general formula (I): in which R is a mono- to tetravalent polymer radical, not more than a third of the radicals R1, R2, and R3 present in the polymer of the formula (I), independently of one another, are alkyl radicals having 1 to 4 carbon atoms, at least a quarter of the radicals R1, R2, and R3 present in the polymer of the formula (I), independently of one another, are ethoxy radicals, any remaining radicals R1, R2, and R3, independently of one another, are methoxy radicals, and in which n is 1 to 4. The invention further relates to a process for preparing the polymers of the formula (I), and also to their use in adhesives, sealants, and coating materials.

Abstract: An antireflection film comprising: a transparent plastic film substrate; a hard coat layer; and a low refractive layer, in this order, wherein the low refractive layer is formed by a curable composition comprising: (a) an inorganic fine particle; (b) at least one of a cationic polymerizable compound having a silyl group within the molecule; a hydrolysate of the compound; and a partial condensate of the compound; and (c) a photo-cationic polymerization initiator.

Abstract: [Problem] There is provided a curable composition having good curability and adhesion by use of a non-organotin catalyst. [Means to Solve] A curable composition comprising (A) an organic polymer having a silicon-containing group being capable of crosslinking by forming siloxane bonds, (B) one or more kinds selected from a titanium catalyst, an aluminum catalyst and a zirconium catalyst and (C) a low molecular weight compound containing a hydrolyzable silicon group and having a molecular weight of from 100 to 1,000, characterized in that a ratio (a/b) of the total mole (a) of titanium atoms, aluminum atoms and zirconium atoms of the component (B) in the composition to the total mole (b) of silicon atoms of the component (C) in the composition is more than 0.4.

Abstract: A method for producing a polymer for semiconductor optoelectronics, comprising the steps of providing a monomer is produced having the formula: wherein: R1 is a hydrolysable group R2 is hydrogen, and R3 is a bridging linear or branched bivalent hydrocarbyl group, said monomer being produced by hydrosilylation of the corresponding starting materials, and homo- or copolymerizing the monomer to produce a polymer.

Abstract: The present invention provides a new class of organic/inorganic hybrid materials having [ER]n rings interconnected by E? atoms. In an embodiment a class of materials called high organic group content periodic mesoporous organosilicas (HO-PMO's) with [SiR]3 rings interconnected by O atoms is described. The measured dielectric, mechanical and thermal properties of the materials suggest that an increased organic content achieved by the [SiR]3 rings of a high organic group content periodic mesoporous organosilica leads to superior materials properties potentially useful for a wide range of applications including microelectronics, separation, catalysis, sensing, optics or electronic printing.

Abstract: A process for producing an epoxy silane oligomer including a reaction glycidoxy silane and/or cycloaliphatic epoxy silane having 2 or 3 allcoxy groups and, optionally, a copolymerizable silane other than glycidoxy and cycloaliphatic epoxy silane, with less than 1.5 equivalents of water in the presence of a catalyst, wherein said water is continuously fed during the reaction.

Abstract: There is provided a curable composition having good adhesion by using a non-organotin catalyst. The curable composition comprises (A) an organic polymer having a silicon-containing group being capable of crosslinking by forming siloxane bonds and (B) one or more kinds selected from a titanium catalyst, an aluminum catalyst and a zirconium catalyst, and is characterized in that a stress at 50% tension is within a range from 0.01 MPa to 0.20 MPa, when determined by adding and mixing 1.5 parts of tin octylate, 0.25 part by weight of laurylamine and 0.6 part by weight of pure water to 100 parts by weight of the component (A), subjecting the mixture to centrifugal defoaming, pouring the mixture carefully into a polyethylene frame not to mix air bubbles thereto, aging the mixture at 23° C. for one hour, and further at 70° C. for 20 hours, punching the obtained 3 mm thick cured sheet according to JIS K6251 to obtain No. 3 dumbbell, and carrying out a tension test (tensile speed: 200 mm/min) at 23° C. at 50% RH.

Abstract: A golf ball comprising a core and a cover layer, wherein at least one of the core or cover layer comprises homo and copolymers of poly(dimethyl siloxane) ionomers, and their blends for improved resiliency and abrasion resistant golf balls.

Abstract: A method of making a golf ball comprising a core and a cover layer, wherein at least one of the core or cover layer comprises homo and copolymers of poly(dimethyl siloxane) ionomers, and their blends for improved resiliency and abrasion resistant golf balls.

Abstract: Linear or branched functionalized polycarbosilanes having an absorbance less than 3.0 ?m?1 at 193 nm and a relatively high refractive index are provided. The functionalized polycarbosilanes contain at least one pendant group that is acid labile or aqueous base soluble. Also disclosed are photoresists formulations containing the functionalized polycarbosilanes that are suitable for use in lithography, e.g., immersion lithography.

Abstract: An insulating-film-forming composition includes: a hydrolysis-condensation product obtained by hydrolyzing and condensing a hydrolyzable-group-containing silane monomer (A) in the presence of a polycarbosilane (B) and a basic catalyst (C); and an organic solvent.

Abstract: Moisture-curing compositions include at least one silane-functional polymer P with at least two terminal groups of formula (I), at least one aminosilane AS and at least one (meth)acrylsilane or anhydriodosilane of formula (II). The compositions have improved adhesive properties and are especially suitable for use as adhesives, sealing materials or coatings, especially as elastic adhesive or sealing materials.

Abstract: A film forming composition with spreading properties derived from an aqueous emulsion comprising (I) colloidal silica core/silicone shell particles consisting of (a) 90 wt % to 10 wt % cores of colloidal silica and (b) 10 wt % to 90 wt % shells of polyorganosiloxane; (II) a polyalkyleneoxide modified trisiloxane; (III) an emulsifier package consisting of at least one anionic surfactant, and (IV) the salt of an acidic polymerization catalyst. The composition may include optional ingredients useful in Personal Care, Hair Care, Skin Care, Agricultural, and Home Care applications.

Abstract: Curable fluoropolyether compositions comprising (a) a polyfluorodialkenyl compound, (b) a fluorinated organohydrogenpolysiloxane, (c) a platinum catalyst, (d) hydrophobic silica powder, (e) a tackifier in the form of a specific silicon compound, and (f) an organosiloxane having a SiH group, an epoxy and/or trialkoxysilyl group, and a perfluoroalkyl or perfluoropolyether group cure to thermoplastic resins to form a durable tight bond at a low temperature within a short time and are readily releasable from metal molds.

Abstract: A poly(arylene ether) composition includes a hydrogenated block copolymer of an alkenyl aromatic compound and a conjugated diene, a flame retardant, and a poly(arylene ether)-polysiloxane block copolymer reaction product that itself includes a poly(arylene ether)-polysiloxane block copolymer. The composition is useful for forming extruded articles, including insulation for wire and cable. The poly(arylene ether)-polysiloxane block copolymer contributes improved flame retardancy and, in many cases, improved physical properties to the composition.

Abstract: An object of the present invention is to solve the problems with conventional polymer electrolyte fuel cells and provide a proton conducting membrane which exhibits an excellent heat resistance and an excellent protonic conductivity and a high dimensional stability even at high temperatures, a method for producing the same and a fuel cell using the same. The proton conducting membrane of the present invention is a proton conducting membrane having particles 1 comprising a metal-oxygen crosslinked structure and the particles 1 have an acid group such as sulfonic acid group incorporated in the surface thereof and form a continuity. The gap 2 between the particles is communicated from the main surface to the opposite surface of the proton conducting membrane to form a proton conducting channel.

Abstract: To provide a material for forming an exposure light-blocking film which includes at least one of a silicon compound expressed by the following structural formula (1) and a silicon compound expressed by the following structural formula (2), wherein at least one of R1 and R2 is replaced by a substituent capable of absorbing exposure light. (where R1 and R2 may be the same or different, and each represents any one of a hydrogen atom, alkyl group, alkenyl group, cycloalkyl group and aryl group which are optionally substituted, and n is an integer of 2 or greater) (where R1, R2 and R3 may be the same or different, at least one of R1, R2 and R3 represents a hydrogen atom and the others represent any one of an alkyl group, alkenyl group, cycloalkyl group and aryl group which are optionally substituted, and n is an integer of 2 or greater).

Abstract: It is an object of the invention to provide a polymer compound that can exhibit high charge mobility when used in an organic transistor. The polymer compound according to a preferred embodiment comprises a repeating unit represented by the following formula (1). [In the formula, R1 represents an alkyl group, alkoxy group, alkylthio group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, substituted silyl group, substituted carboxyl group, monovalent heterocyclic group, cyano group or a fluorine atom, and l is an integer of 2 to 8. The multiple R1 groups may be the same or different.

Abstract: An organopolysiloxane represented by the following general formula (A), (B) or(C) SinR12n+2On?1??(A) SinR12nOn??(B) SinR12n+2R2kOn?k??(C) wherein R1 may be the same with or different from each other and is a hydrogen atom or a monovalent organic group, R2 is an alkylene group having 2 to 6 carbon atoms, n is an integer of from 2 to 40 and k is an integer of 1 to 3, characterized in that at least two R1's are represented by the following formula (i): wherein X is a hydrolyzable group, R3 is an alkyl group having 1 to 4 carbon atoms or a phenyl group, y is an integer of from 1 to 5 and a is 2 or 3; and one SiOSi bond is replaced with a bond represented by the following formula (iii): SiQRf2QSi??(iii) wherein Rf1 is a monovalent group containing a perfluoroether residue, Rf2 is a divalent group containing a perfluoroether residue, and Q is a divalent organic group.

Abstract: The present invention relates to a method of making a swellable sol-gel composition that involves the use of a bridged silane precursor. The resulting sol-gel includes residual silanols, which are derivatized with a reagent having at least one silanol-reactive group and at least one alkyl group; and the sol-gel is then dried. Sol-gels of the invention are demonstrated to swell up to about 8-10 times their original volume in the presence of a non-polar sorbate. The sol-gel compositions can be used in a sorbate-activated actuator or in a detector for non-polar sorbates. The sol-gel compositions can further be used to take up non-polar sorbates for purposes of chemical remediation, extraction from aqueous systems or vapor, and chemical sensing.

Abstract: Implantable or insertable medical devices comprising a surface region that is modified by covalently coupling a molecular species (or a combination of molecular species) to the same. The molecular species are selected such that the resulting modified surface region has critical surface energy between 20 and 30 dynes/cm. In certain embodiments, the covalently coupled molecular species comprise one or more methyl groups. An advantage of the present invention is that novel medical devices are provided, which have a surface with a critical surface energy value that has been shown to display enhanced biocompatibility, including enhanced thromboresistance, relative to other surfaces.

Abstract: Acyclic diene metathesis (ADMET) has been utilized in the synthesis of carbosilane and carbosiloxane polymers bearing a latent reactive methoxy-functional group on each repeat unit. The polymerization results in a linear thermoplastic polymer. The latent reactive methoxy groups remain inert during polymerization; however, exposure to moisture triggers hydrolysis and the formation of a chemically cross-linked thermoset. The thermoset's properties can be modified by varying the ratio of carbosilane and carbosiloxane repeat units in the final material. Also, increasing cross-link density by using cross-linkable chain-end groups and increasing the run length of the soft phase, maximizing phase separation and elasticity, allows for the synthesis of elastic thermosets exhibiting good tensile strength. Adding a trifunctional ADMET active chain-end cross-linker to the system improved the mechanical behavior of the resulting polymer.

Abstract: A method for processing polyester wastes, especially used polyester bottles, which comprises shredding, washing, drying and melting the waste mixture to obtain a starting raw material wherein a modifying agent selected from the group comprising a combination of polysiloxane and a plasticizer selected from the group of phthalates, or a combination of silazanes and silanes is added to the shredded and dried waste mixture, the amount of the modifying agent being 4 to 6% by weight, based on the waste mixture.

Abstract: Siloxane polymer compositions and methods of manufacturing a capacitor are described. In some embodiments, a mold layer pattern is formed on a substrate having a conductive structure, and the mold layer pattern has an opening to expose the conductive structure. A conductive layer is formed on the substrate. A buffer layer pattern is formed on the conductive layer formed in the opening. The buffer layer pattern includes a siloxane polymer represented by the following Chemical Formula 1. The conductive layer is selectively removed to form a lower electrode. The mold layer pattern and the buffer layer pattern are removed. A dielectric layer and an upper electrode are formed on the substrate to form a capacitor. The methods may simplify manufacturing processes for a capacitor and a semiconductor device, and may improve their efficiencies.

Abstract: To provide a material for forming an exposure light-blocking film which includes at least one of a silicon compound expressed by the following structural formula (1) and a silicon compound expressed by the following structural formula (2), wherein at least one of R1 and R2 is replaced by a substituent capable of absorbing exposure light.

Abstract: The invention provides branched copolymers as precursors for preparing silicon carbide (SiC) ceramics represented by the general formulae: [Si(˜)RC(˜)H]xn[SiR1R2CH2]yn,??Formula Type-I wherein n is the degree of polymerization, 0.1?x<0.8, 0.2?y<0.9 and x+y=1; and R=methyl or H, R1 and R2 are randomly composed of hydrogen (H), allyl, methyl (Me), phenyl (Ph), propargyl or vinyl. Another branched copolymer is represented by the general formula: [Si(˜)RC(˜)H]xn[SiR1R2CH2]yn[SiR3R4CH2]zn??Formula Type-II wherein n is the degree of polymerization, 0.1?x<0.8, 0?y<0.8, 0.2?z<0.8 and x+y+z=1; and R=methyl or H, R1 and R2 are randomly composed of hydrogen (H), methyl (Me) and phenyl; R3 and R4 are randomly composed of H, allyl, methyl, phenyl (Ph), propargyl, and vinyl. The invention also provides methods for the preparation of such branched copolymers.