Unsaturated polyester resin （UPR）/acrylate-terminated polyurethane （ATPU）/organo-modified montmorillonite （OMMT） nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prep...Unsaturated polyester resin （UPR）/acrylate-terminated polyurethane （ATPU）/organo-modified montmorillonite （OMMT） nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene （S） and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82：15：3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.展开更多
Silane terminated prepolymers for adhesives, sealants and coatings are of </span></span><span><span><span style="font-family:"">great <span>industrial importance. The...Silane terminated prepolymers for adhesives, sealants and coatings are of </span></span><span><span><span style="font-family:"">great <span>industrial importance. They are very important because of their low toxicity</span><span> over polyurethanes, silicones, and solvent-based products. Hence</span>, many pieces of literature which deal with the synthesis, properties and applications of this Si<span>lane terminated polymers hybrid system exist. Silylated polyether (MS polymers) </span>and Silylated Polyurethane Polymers (SPUR) are the bases for nu<span>merous sealants, adhesives and coatings used worldwide. A hybrid system mixed with </span><span>organic-polyurethane proportion and inorganic-alkoxysilane proportion</span> <span>com</span>bines the benefits of conventional polyurethane and silicone-based products.<span> This article reviews the chemistry of MS polymers and SPUR and their</span> <span>ad</span><span>vantages and disadvantages in silyl terminated prepolymer-based adhesives</span>, sea<span>lants and coatings as well as provides information on different end applications.展开更多
A kind of polyurethane/organically modified montmorillonite (PU/OMMT) nanocomposite based on poly(propylene glycol), 1,4 butanediol and 4,4 diphenylmethane diisocyanate was prepared by solution intercalation technolog...A kind of polyurethane/organically modified montmorillonite (PU/OMMT) nanocomposite based on poly(propylene glycol), 1,4 butanediol and 4,4 diphenylmethane diisocyanate was prepared by solution intercalation technology.The results of wide angle X ray diffraction and TEM showed that the gallery distance of OMMT in the PU matrix was 3～4?nm.As the hard segment content increased,the molecular chains of PU had difficulty in diffusing into the silicate layer galleries for intercalation.Transmission electron microscopy photographs showed that OMMT layers were dispersed well into the PU matrix on the nanometer scale,and an ordered intercalation structure was obtained.Compared with those of pure PU,the tensile strength,the tear strength and the elongation at break increased by about 43%,28% and 18% for PU/OMMT(92/8),respectively.The water absorption decreased with increasing the amount of OMMT.Thermogravimetric analysis showed that the PU/OMMT nanocomposites displayed a little higher thermal resistance than that of pure PU in the second pyrolysis stage.展开更多
基金This research was supported by the Science and Technology Key Project of Guangdong(A1070203).
文摘Unsaturated polyester resin （UPR）/acrylate-terminated polyurethane （ATPU）/organo-modified montmorillonite （OMMT） nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene （S） and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82：15：3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.
文摘Silane terminated prepolymers for adhesives, sealants and coatings are of </span></span><span><span><span style="font-family:"">great <span>industrial importance. They are very important because of their low toxicity</span><span> over polyurethanes, silicones, and solvent-based products. Hence</span>, many pieces of literature which deal with the synthesis, properties and applications of this Si<span>lane terminated polymers hybrid system exist. Silylated polyether (MS polymers) </span>and Silylated Polyurethane Polymers (SPUR) are the bases for nu<span>merous sealants, adhesives and coatings used worldwide. A hybrid system mixed with </span><span>organic-polyurethane proportion and inorganic-alkoxysilane proportion</span> <span>com</span>bines the benefits of conventional polyurethane and silicone-based products.<span> This article reviews the chemistry of MS polymers and SPUR and their</span> <span>ad</span><span>vantages and disadvantages in silyl terminated prepolymer-based adhesives</span>, sea<span>lants and coatings as well as provides information on different end applications.
文摘A kind of polyurethane/organically modified montmorillonite (PU/OMMT) nanocomposite based on poly(propylene glycol), 1,4 butanediol and 4,4 diphenylmethane diisocyanate was prepared by solution intercalation technology.The results of wide angle X ray diffraction and TEM showed that the gallery distance of OMMT in the PU matrix was 3～4?nm.As the hard segment content increased,the molecular chains of PU had difficulty in diffusing into the silicate layer galleries for intercalation.Transmission electron microscopy photographs showed that OMMT layers were dispersed well into the PU matrix on the nanometer scale,and an ordered intercalation structure was obtained.Compared with those of pure PU,the tensile strength,the tear strength and the elongation at break increased by about 43%,28% and 18% for PU/OMMT(92/8),respectively.The water absorption decreased with increasing the amount of OMMT.Thermogravimetric analysis showed that the PU/OMMT nanocomposites displayed a little higher thermal resistance than that of pure PU in the second pyrolysis stage.
