Abstract:
In the present invention high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes and methods for making and using these membranes have been developed. The cross-linked polybenzoxazole and polybenzothiazole polymer membranes are prepared by: 1) first synthesizing polyimide polymers comprising pendent functional groups (e.g., -OH or -SH) ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone; 2) fabricating polyimide membranes from these polymers; 3) converting the polyimide membranes to polybenzoxazole or polybenzothiazole membranes by heating under inert atmosphere such as nitrogen or vacuum; and 4) finally converting the membranes to high performance cross-linked polybenzoxazole or polybenzothiazole membranes by a crosslinking treatment, preferably UV radiation. The membranes can be fabricated into any convenient geometry. The high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes of the present invention are suitable for a variety of liquid, gas, and vapor separations.
Abstract:
The invention concerns a polybenzazole block copolymer suitable for solid polymer electrolyte membranes application comprising: at least one block (Bl) comprising recurring units (R), more than 50 % of said recurring units comprising at least one benzimidazole group (formula 1a and 1b) and at least one sulfonic acid group (formula 2) [recurring units (R1)]; wherein E in formula 1a can be a substituted or non-substituted carbon atom or nitrogen atom, and Q in formula 1 can be a hydrogen atom or a group comprising a sulfonic acid group; and at least one block (B2) comprising recurring units (R'), more than 50 % by moles of said recurring units comprising at least one benzazole group chosen among benzoxazole group (formula 3a and 3b) and benzothiazole group (formula 4a and 4b) [recurring units (R2)], wherein E' and E" in formula 3a and 4a, respectively, can be a substituted or non-substituted carbon atom or nitrogen atom, and the block (B2) is free from sulfonic acid groups. The invention also relates to a polybenzazole polymer composition thereof, a solid polymer electrolyte membrane therefrom, a solid polymer electrolyte doped membrane therefrom, and the fuel cell therefrom.
Abstract:
Polyazole-based polymer membranes, such as polyoxadiazole or -triazole-based membranes, are disclosed. The membranes are useful in gas separation and reverse osmosis processes. The gas separation membranes of the present invention exhibit improved methane separation factors, whereas the reverse osmosis membranes present high chlorine resistance as well as a salt rejection of at least 99 percent.
Abstract:
This invention relates in general to the formation of thick films having a biaxial molecular orientation. Such films are prepared in accordance with the present invention from rod-like extended chain aromatic-heterocyclic ordered polymers. Such films have high tensile strength, modulus, and environmental resistance characteristics. A preferred ordered polymer for use in the present invention is poly(para-phenylenebenzo bisthiazole), (PBT), a compound having structure (I). The present invention is also directed to methods and apparatus suitable for producing biaxially oriented films, coatings, and like materials from ordered polymers, preferably PBT.
Abstract:
The present disclosure provides an antimicrobial substrate including a substrate and a polythiophene polymer. The polythiophene polymer has a number of repeated monomer units from n is 5-14 or 30 to 120, a number average molecular weight (Mn) from 1,000 to 4,000 or 10,000 to 40,000; and a polydispersity index (PDI) from 1 to 1.3. The present disclosure also provides the polythiophene polymer and uses thereof.
Abstract:
The present invention concerns a method of producing a thermally rearranged polybenzoxazole, polybenzimidazole or polybenzothiazole (collectively denominated "TR PBX"), thermally arranged PBX and membranes comprising the same. The inventive method includes the method steps: preparing a polyimide or aromatic polyamide as a precursor polymer in a solution, wherein in each recurring monomer unit of the precursor polymer an aromatic ring is located adjacent to the nitrogen atom of the imide group or amide group of the monomer unit, wherein in some or all of the recurring monomer units the aromatic ring is functionalized with an -XR group as a side chain at the ortho -position to the nitrogen atom, wherein X=O, N or S, and performing a thermal treatment to carry out a thermal rearrangement resulting in the thermally rearranged polybenzoxazole, polybenzimidazole or polybenzothiazole, wherein R is an allyl group or an allyl-based group, wherein a processing temperature used during the thermal treatment for the thermal rearrangement is between 0 °C and 350 °C.
Abstract:
In the present invention high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes and methods for making and using these membranes have been developed. The cross-linked polybenzoxazole and polybenzothiazole polymer membranes are prepared by: 1) first synthesizing polyimide polymers comprising pendent functional groups (e.g., -OH or -SH) ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone; 2) fabricating polyimide membranes from these polymers; 3) converting the polyimide membranes to polybenzoxazole or polybenzothiazole membranes by heating under inert atmosphere such as nitrogen or vacuum; and 4) finally converting the membranes to high performance cross-linked polybenzoxazole or polybenzothiazole membranes by a crosslinking treatment, preferably UV radiation. The membranes can be fabricated into any convenient geometry. The high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes of the present invention are suitable for a variety of liquid, gas, and vapor separations.
Abstract:
Block copolymers can be formed from heterocyclic polymers such as PBO and thermoplastic polymers such as polyamide or poly(aromatic ether ketone). The block copolymer compositions are thermoplastic and do not experience substantial phase separation, even at about their glass transition temperature. The block copolymer compositions can be formed into fibers, films and laminate or compression-molded articles. PBO, PBI and PBT polymers terminated by active aromatic rings or acylating groups are particularly useful for making the block copolymers.
Abstract:
The present invention concerns a process for making a polyareneazole polymer, comprising the steps of : a) contacting azole-forming monomers, preferably 2, 3, 5, 6-tetraaminopyridine and 2,5-dihydroxyterephthalic acid metal powder, and optionally P 2 O 5 , in polyphosphoric acid to form a mixture; b) blending the mixture at a temperature of from 50°C to 110°C; c) further blending the mixture at a temperature of up to 145°C to form a solution comprising an oligomer; d) optionally, degassing the solution; and e) reacting the oligomer solution at a temperature of 160°C to 250°C for a time sufficient to form a polymer.