- Efficient concrete foam stabilizer and preparation method thereof
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The invention discloses an efficient concrete foam stabilizer and a preparation method thereof, according to the efficient foam stabilizer, polyol is subjected to an esterification reaction to form ester bonds, and the ester bonds are connected with amphiphilic side chains, and the number of the amphiphilic side chains is 3-7; one end of the amphiphilic side chain is a hydrophobic chain segment, and the other end of the amphiphilic side chain is a hydrophilic unit; wherein the hydrophobic chain segment is an alkyl chain (R) with 8-14 carbons, and the hydrophilic unit is 2-10 ethylene oxide units. The efficient concrete foam stabilizer is a multi-chain type surfactant, and the multi-chain type surfactant is hydrolyzed under the alkaline condition to release an air-entraining type surfactant. The efficient concrete foam stabilizer has an excellent effect of stabilizing the air content of concrete, meanwhile, hardened concrete has a better pore structure, and the hardening strength of the concrete cannot be greatly influenced.
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Paragraph 0027; 0040-0041
(2021/07/17)
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- Combinatorial synthesis of PEG oligomer libraries
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A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
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Page/Page column 9
(2010/02/15)
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- FORMATION OF HETEROATOM CONTAINING DERIVATIVES OF PARAFFINS
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A process by which alkyl halides may be reacted (coupled) with nucleophilic materials in the presence of a homogeneous catalyst system. The process comprises reacting (coupling) alkyl halides with a nucleophilic material in the presence of a homogeneous catalyst system to produce derivatives of alkyl halides, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds.
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Page/Page column 10-12
(2008/06/13)
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- CONVERSION OF ALKYLHALIDES INTO ALCOHOL ALKOXYLATES
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A process for converting alkyl halides to alkyl alcohol alkoxylates is described. This is a direct alkoxylation because the alkyl alcohol alkoxylates are made without going through an alkyl alcohol intermediate. The process comprises direct alkoxylation coupling of alkyl halides with a nucleophilic material in the presence of a homogeneous catalyst system to produce alkyl alcohol alkoxylates, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds. A process for converting alkanes (paraffins) to alkyl alcohol alkoxylates is also described. This method comprises a) halogenation of at least one alkane to produce at least one alkyl halide; and b) direct alkoxylation coupling of at least a portion of the alkyl halide with a nucleophilic material in the presence of a homogeneous catalyst system to produce alkyl alcohol alkoxylates, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds.
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Page/Page column 10-12
(2008/06/13)
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- Organotin-containing composition for the stabilization of polymers of vinyl chloride
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An organotin-containing composition for the stabilization of polymers or copolymers of vinyl chloride in which there is incorporated a stabilizing amount of an organotin compound containing at least two tin atoms and which is a mercapto, hydroxy or alkoxy substituted ester of a mercapto acid substituted organotin mercapto acid diester.
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- Topical mosquito repellents VII: Alkyl triethylene glycol monoethers
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Normal and branched chain aliphatic monoethers of triethylene glycol are effective topical mosquito repellents. In terms of duration of protection, they are generally superior to the corresponding diethylene glycol analogs, and some are superior to diethyltoluamide. The n heptyl monoether of triethylene glycol affords double the protection time of diethyltoluamide under controlled laboratory conditions, and appears to be a useful new mosquito repellent.
- Johnson,DeGraw,Engstrom,Skinner,Brown,Skidmore,Maibach
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p. 693 - 695
(2007/10/05)
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