摘要:
There are provided processes and compositions for obtaining organic polymeric materials having near-zero uniaxial thermal expansion coefficients. According to one embodiment, an organic polymer having a negative uniaxial thermal expansion coefficient is treated by thermal processing under conditions sufficient to cause at least a portion of the polymer chains to become misaligned, thereby decreasing the magnitude of this thermal expansion coefficient to nearly zero. According to a second embodiment, one or more organic polymers having a negative uniaxial thermal expansion coefficient are combined with one or more materials having a positive thermal expansion coefficient to yield a composite material having a uniaxial thermal expansion coefficient which is nearly zero.Useful in the practice of the invention are polyacetylenes having a negative macroscopic thermal expansion coefficient, which are obtained by the solid-state polymerization of crystalline monomers containing two or more conjugated acetylene groups.
摘要:
Acetylenic complexes are disclosed that are useful as environmental indicating materials whereby exposure thereof to environmental stimuli induces a color change. These complexes contain at least one effective complexing metal and at least one acetylenic compound of the general formula:[R--(C"C).sub.a --(CH.sub.2).sub.b --(C"C).sub.c ].sub.2.dHXWherein a is 1 or 2, b is about 0-5; c is 0 or 1; with the proviso that when a is 1, b and c are 0, when a is 2, b is about 0-5 and c is 0 or 1; and R is --(CH.sub.2).sub.n -NHC(O)NHR'; wherein n is an integer of about 1 to 10; and R' is selected from the group consisting of: (a) hydrogen; (b) cycloalkyl; (c) alkenyl; (d) cycloalkenyl; (e) alkyl; (f) phenyl; (g) alkoxy; (h) alkoxy alkyl; and (i) alkoxycarbonylalkyl.
摘要:
Liquid phase processable crystalline diacetylene polymers are obtained by the solid state reaction of monomers having the formulaR.sub.1 --C.tbd.C--C.tbd.C--R.sub.2where R.sub.1 and R.sub.2 are independently selected from the group consisting of(a) CH.sub.3 (CH.sub.2).sub.m --(b) HO(CH.sub.2).sub.n -- and(c) R.sub.3 NHOCO(CH.sub.2).sub.p --where "m" is an integer of from 0 to 15, "n" is an integer of from 1 to 15, "p" is an integer of from 1 to 15, and R.sub.3 is a member selected from the group consisting of(i) C.sub.6 H.sub.5 (CH.sub.2).sub.r --(ii) CH.sub.3 (CH.sub.2).sub.r -- and(iii) C.sub.10 H.sub.7 (CH.sub.2).sub.r --where "r" is an integer of from 0 to 11; with the proviso that where R.sub.1 and R.sub.2 are the same and are either (b) or (c), neither "n" nor "p" equals 1; and with the further proviso that where R.sub.1 and R.sub.2 are different and are either (b) or (c), the sum of "n" plus "p" is greater than 2.Polymerization proceeds by 1,4-addition reaction at each diacetylene group to produce a crystalline diacetylene polymer having the structure ##STR1## or the alternate head-to-head structure: where R.sub.1 and R.sub.2 are as defined above. The structure of such polymers is characterized by Raman intense .nu..sub.C.dbd.C and .nu.C.tbd.C vibrations at, respectively 1450 to 1540 cm.sup.-1 and 2060 to 2140 cm.sup.-1, which replace the Raman intense .nu..sub.C.tbd.C vibration at approximately 2260 cm.sup.-1 in the monomer. The polymers are further characterized by intense optical dichroism, which is indicative of a high degree of chain alignment, and by high thermal dimensional stability. They are useful as photoconductive materials, pigments, high strength materials, and optical polarizers.
摘要:
Compositions containing at least two conjugated acetylene groups (-C.tbd.C-C.tbd.C-) are suitable as integral time-temperature history indicators. These compositions exhibit sequences of irreversible color changes at combinations of times and temperatures specific to each composition. Thus, when supported on the surface of a product or on a substrate affixed to a product, they are useful for indicating whether a perishable (e.g., foodstuff, pharmaceutical, chemical, etc.) has been exposed to an undesirable time-temperature history that results in substantial degradation of the perishable or whether a product has been exposed to a desirable time-temperature history during processing (e.g., the sterilization of a foodstuff or biomedical material).
摘要:
A new process is described which is useful for producing novel articles of manufacture useful for monitoring the time-temperature history of perishable items. The process initially involves forming a solution comprised of a diacetylenic monomer and a solvent. The solution is frozen, and the frozen solution having crystalline diacetylenic monomer therein is irradiated to partially polymerize the diacetylenic monomer. Partial polymerization of the crystalline diacetylenic monomer admixed with frozen solvent results in the production of a novel article of manufacture having color. The novel article of manufacture is comprised of frozen solvent, diacetylenic monomer, and colored polydiacetylene. Due to the intensity of the color of the polydiacetylene, the entire article of manufacture appears to be colored.The colored article of manufacture may be attached to various perishables to monitor the shelf life of the perishables. upon exposure to temperatures above a critical temperature, the frozen solvent melts and extracts unreached monomer from the colored polymer, thereby causing a sharp color transition which indicates that the perishable should possibly be discarded.
摘要:
A family of acetylenic complexes especially useful as environmental indicators is provided. The complexes include at least one complexing acid and one acetylenic compound of the formula:[R--(C.tbd.C).sub.a --(CH.sub.2).sub.b --(C.tbd.C).sub.c ].sub.2.dHXwherein, a is 1 or 2; b is about 0-5; c is 0 or 1; d is above 0 to about 2, with the proviso that when a is 1, b and c are 0, and when a is 2, b is about 0-5 and c is 0 or 1; and R is --(CH.sub.2)n--NHC(O)NHR'; wherein n is an integer of about 1 to 10; and R' is selected from a group consisting of hydrogen, cycloalkyl, alkenyl, cycloalkenyl, aklyl, phenyl, alkoxyl, alkoxylcarbonylalkyl, and X is a complexing acid.
摘要:
Water-soluble polyacetylenic alkali metal salts from monomers and polymers of carboxymethyl urethanes of di-, tetra-, and hexayne diols, or from the corresponding diacids; useful in thermal and irradiation exposure indicators and/or in detection and/or removal of nonalkali metal ions dissolved in aqueous media.
摘要:
Water-soluble polyacetylenic alkali metal salts from monomers and polymers of carboxymethyl urethanes of di-, tetra-, and hexayne diols, or from the corresponding diacids; useful in thermal and irradiation exposure indicators and/or in detection and/or removal of nonalkali metal ions dissolved in aqueous media.
摘要:
There are provided composites having near-zero uniaxial thermal expansion coefficients. One or more polyacetylenes having a negative uniaxial thermal expansion coefficient are uniaxially or biaxially oriented within one or more solid matrix materials having a positive thermal expansion coefficient to yield a composite material having a uniaxial thermal expansion coefficient which is nearly zero. The polyacetylenes are obtained by the solid-state polymerization of crystals of monomers containing at least one --C.tbd.C--C.tbd.C-- grouping per molecule. Also provided are processes for producing the above-described composites.
摘要翻译:提供具有近零单轴热膨胀系数的复合材料。 具有负单轴热膨胀系数的一种或多种聚乙炔在具有正热膨胀系数的一种或多种固体基质材料中单轴或双轴取向,得到具有几乎为零的单轴热膨胀系数的复合材料。 聚乙炔通过每分子含有至少一个-C 3 C 1 -C 3 C 3 C C基团的单体的晶体的固态聚合而获得。 还提供了用于生产上述复合材料的方法。
摘要:
A new process is described which is useful for producing novel articles of manufacture useful for monitoring the time-temperature history of perishable items. The process initially involves forming a solution comprised of a diacetylenic monomer and a solvent. The solution is frozen, and the frozen solution having crystalline diacetylenic monomer therein is irradiated to partially polymerize the diacetylenic monomer. Partial polymerization of the crystalline diacetylenic monomer admixed with frozen solvent results in the production of a novel article of manufacture having color. The novel article of manufacture is comprised of frozen solvent, diacetylenic monomer, and colored polydiacetylene. Due to the intensity of the color of the polydiacetylene, the entire article of manufacture appears to be colored.The colored article of manufacture may be attached to various perishables to monitor the shelf life of the perishables. Upon exposure to temperatures above a critical temperature, the frozen solvent melts and extracts unreacted monomer from the colored polymer, thereby causing a sharp color transition which indicates that the perishable should possibly be discarded.