摘要:
A lightweight absorbent foam is produced using a high internal phase emulsion (HIPE), the production of which incorporates the use of capillary viscosity measurements as an in-line diagnostic for HIPE quality. The in-line diagnostics yield measurements of viscosity slope and amplitude. These measurements offer several advantages for monitoring emulsion quality, including stable high resolution measurement of hardware-independent parameters of the whole flow, without the need for sampling.
摘要:
In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties by first advancing one or more of the monomers. All or a portion of the monomers are advanced in the presence of an advancement initiator or a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid. Then, a water-in-oil high internal phase emulsion is formed with the advanced monomers and optionally additional monomers or the advanced monomers are added to a water-in-oil high internal phase emulsion containing other monomers. The emulsions containing the advanced monomers are cured. The process provides an improved method to incorporate volatile monomers in the porous polymeric material. The curing time is further reduced by carrying out the polymerization and crosslinking in the presence of a alkylperoxycarbonate or a alkylperoxycarboxylate polymerization initiator that is branched at the 1-position and/or the .alpha.-position.
摘要:
In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties by first advancing one or more of the monomers. All or a portion of the monomers are advanced in the presence of an advancement initiator or a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid. Then, a water-in-oil high internal phase emulsion is formed with the advanced monomers and optionally additional monomers or the advanced monomers are added to a water-in-oil high internal phase emulsion containing other monomers. The emulsions containing the advanced monomers are cured. The process provides an improved method to incorporate volatile monomers in the porous polymeric material. The curing time is further reduced by carrying out the polymerization and crosslinking in the presence of a alkylperoxycarbonate or a alkylperoxycarboxylate polymerization initiator that is branched at the 1-position and/or the .alpha.-position.
摘要:
A lightweight absorbent foam is produced using a high internal phase emulsion (HIPE), the production of which incorporates the use of capillary viscosity measurements as an in-line diagnostic for HIPE quality. The in-line diagnostics yield measurements of viscosity slope and amplitude. These measurements offer several advantages for monitoring emulsion quality, including stable high resolution measurement of hardware-independent parameters of the whole flow, without the need for sampling.
摘要:
In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties or substantially affecting the emulsion by carrying out the curing in multiple-stages. The emulsion is first pre-cured at a temperature less than about 65.degree. C. until the emulsion reaches a Rheometrics dynamic shear modulus of at least about 500 and subsequently curing at a temperature above about 70.degree. C.
摘要:
In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties or substantially affecting the emulsion by carrying out the curing in multiple-stages. The emulsion is first pre-cured at a temperature less than about 65.degree. C. until the emulsion reaches a Rheometrics dymanic shear modulus of at least about 500 and subsequently curing at a temperature above about 70.degree. C.
摘要:
A process for the production of a stable curable water-in-oil high internal phase emulsion containing monomers as the continuous phase is provided by adding an initiator subsequent to formation of a water-in-oil high internal phase emulsion. The process forms uniform stable water-in-oil high internal phase emulsions in a continuous mixing process. These curable water-in-oil high internal phase emulsions are useful for the preparation of low density porous crosslinked polymeric materials.
摘要:
This invention relates to a process for the alkylation of methylbenzene to produce ethylbenzene and styrene. In this process methylbenzene and methanol are contacted with a catalyst formed from a zeolite and an alkali(ne earth) metal compound wherein said compound is selected from alkaline earth metal compound and a mixture of alkaline earth metal compound and alkali metal compound and wherein the sum of the amount of the alkali(ne earth) metal in the compound plus any metal cation exchanged into the zeolite is in excess of that required to provide a fully metal cation-exchanged zeolite.
摘要:
This is an improvement upon a process which comprises anionically polymerizing monomers with an anionic polymerization initiator in a suitable solvent thereby creating a living polymer. The improvement comprises terminating the polymerization by the addition of a terminating agent selected from the group consisting of hydrocarbons containing a C-H group where the carbon is connected directly to a triply-bound carbon, hydrocarbons containing a C-H group where the carbon is connected directly to two doubly-bound carbons and hydrocarbons containing a C-H group where the carbon is connected directly to at least 2 aromatic rings, whereing none of said hydrocarbons contain additional aliphatic unsaturation.
摘要:
This invention is a process for the catalytic cracking of parafins to produce olefins in high yield while minimizing production of aromatics. The catalyst used is a zeolite in combination with an alkali(ne earth) metal compound wherein the sum of the amount of the alkali(ne earth) metal in the compound plus any metal cation exchanged into the zeolite is in excess of that required to provide a fully metal cation-exchanged zeolite.