ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Hits per page

hits 1 - 5 | 5 hits

Sorting

Electronic Resource

Molecular composite films from polybenzoxazole and crosslinked polymer matrixes (1997)

McGee, Robert L. ; So, Ying-Hung ; Martin, Steve J. ; [et al.]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2157-2165

add to mindlist on the mindlist

Details

ISSN: 0887-624X

Keywords: poly(p-phenylenebenzobis(thiazole)) ; poly(p-phenylenebenzobis(oxazole)) ; film ; molecular composite ; benzocyclobutene ; phase separation ; interlayer integrity ; tensile strength ; tensile modulus ; delamination resistance ; film density ; coefficient of thermal expansion ; thermal stability ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Films consisting of a rigid-rod polymer and thermoset resin matrixes were prepared. Poly{(benzo[1,2-d : 5,4-d′]bis(oxazole-2,6-diyl))-1,4-phenylene} (PBO) in polyphosphoric acid (PPA) was blended with 2,6-bis(4-benzocyclobutene) benzo[1,2-d : 5,4-d′]bis(oxazole) (1), and films were extruded from these solutions. The coagulated films were soluble in methanesulfonic acid (MSA). After heat treatment at 300°C, the films became insoluble in MSA. Crosslinked films were homogeneous and did not show phase segregation between the two components. These were composite films at the molecular level. Transmission electron microscopy (TEM) showed enhanced interlayer integrity and reduced microfibril separation for the molecular composite films as compared to normal PBO film. These films had significantly better torsion and tension delamination resistance. The incorporation of a second component did not sacrifice the tensile properties of PBO film. Thermal stability of these composite films was only slightly lower than that of normal PBO film. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2157-2165, 1997

Additional Material: 8 Ill.

Type of Medium: Electronic Resource

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Electronic Resource

Poly(p-Phenylenebenzobisoxazole) fiber with polyphenylene sulfide pendent groups (1995)

So, Ying-Hung ; Bell, Bruce ; Heeschen, Jerry P. ; [et al.]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 159-164

add to mindlist on the mindlist

Details

ISSN: 0887-624X

Keywords: poly(p-phenylenebenzobisoxazole) ; polyphenylene sulfide ; pendent group ; crosslinking ; heat treatment ; compressive strength ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Poly(p-phenylenebenzobisoxazole) (PBO) fiber with polyphenylene sulfide (PPS) pendent groups was made to improve PBO fiber compressive strength by crosslinking. PPS moieties allowed the polymeric network to crosslink at heat-treatment temperatures at which PBO does not thermally degrade. PBO-PPS fiber heat-treated for 30 s at 600°C did not dissolve or break up in methanesulfonic acid. Compressive strength of crosslinked fiber was about 20% better than that of unmodified PBO fiber. In another experiment, 10 mol % of 2,5-diphenylsulfideterephthalic acid was incorporated into PBO fiber. The side chain of one phenyl sulfide unit was too short to enhance crosslinking, and the fiber had about the same compressive strength as unmodified PBO fiber. © 1995 John Wiley & Sons, Inc.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/pola.1995.080330118

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Molecular composite fibers from rigid rod polymers and thermoset resin matrixes (1995)

So, Ying-Hung ; Sen, Ashish ; Kim, Peter ; [et al.]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 2893-2899

add to mindlist on the mindlist

Details

ISSN: 0887-624X

Keywords: poly(p-phenylenebenzobisthiazole) ; poly(p-phenylenebenzobisoxazole) ; fiber ; molecular composite fiber ; benzocyclobutene ; compressive strength ; tensile strength ; tensile modulus ; phase separation ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Fibers consisting of a rigid rod polymer and thermoset resin matrices were prepared. Poly(benzo-[1,2-d : 5,4-d′]bisoxazole-2,6-diyl)-1,4-phenylene} (PBO) in polyphosphoric acid (PPA) was blended with isophthaloyl bis-4-benzocyclobutene (1) or 2,6-bis-4-benzocyclobutene benzo[1,2-d: 5,4-d′]bisoxazole (2), and fibers were spun from these dopes. As-spun fibers that did not show phase segregation between the two components as examined with an optical microscope, were soluble in methanesulfonic acid (MSA). After heat treat-ment, the fibers swelled but did not dissolve in MSA. A fiber cross section of heat-treated PBO-1 fiber showed well-dispersed benzocyclobutene polymer domains of 200-500 Å by transmission electron microscopy (TEM). Films cast from MSA solutions of PBO and 2 were homogeneous, and TEM of heat-treated fiber showed only one phase. A molecular composite fiber was made. Some of these fibers showed 20-30% improvement in compressive strength over unmodified PBO fiber. © 1995 John Wiley & Sons, Inc.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/pola.1995.080331706

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Poly(terephthalic acid anhydride) as a latent monomer in polybenzoxazole synthesis (1994)

So, Ying-Hung

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1899-1902

add to mindlist on the mindlist

Details

ISSN: 0887-624X

Keywords: poly(p-phenylenebenzobisoxazole) ; poly(terephthalic acid anhydride) ; 1,3-diamino-4,6-dihydroxybenzene ; polyphosphoric acid ; intrinsic viscosity ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: High molecular weight poly(p-phenylenebenzobisoxazole) (PBO) was prepared from poly(terephthalic acid anhydride) (PTAA) and 1,3-diamino-4,6-dihydroxybenzene dihydrogenchloride in polyphosphoric acid (PPA). PTAA may react directly with the o-aminophenol groups to form benzoxazoles or react with PPA to generate terephthalic acid (TA) of very small particle size, which dissolves readily in PPA. PTAA provides the advantages of bypassing the requirement of small particle size TA, reducing the amount of water liberated by half, and possibly providing faster kinetics in PBO synthesis. © 1994 John Wiley & Sons, Inc.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/pola.1994.080321011

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Polybenzoxazole from 1,4-bis(trichloromethyl)benzene (1997)

So, Ying-Hung

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2143-2145

add to mindlist on the mindlist

Details

ISSN: 0887-624X

Keywords: poly(phenylenebenzobisoxazole) ; poly(phenylenebenzobisthiazole) ; 1,4-bis(trichloromethyl)benzene ; micronized terephthalic acid ; polyphosphoric acid ; methanesulfonic acid ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: High molecular weight poly(phenylenebenzobisoxazole) (PBO) was synthesized from 1,3-diamino-4,6-dihydroxybenzene dihydrochloride (1) and 1,4-bis(trichloromethyl)benzene (3) in polyphosphoric acid (PPA) or a mixture of PPA and methanesulfonic acid. When PPA was used as the solvent, 3 was first converted in situ to terephthalic acid before 1 was added to minimize degradation of 1. Compound 3 did not need to be sealed from atmospheric moisture because the trichloromethyl groups were not moisture sensitive. It was not necessary to use micronized 3. Adjustment of P2O5 content was optional for this reaction because no water was liberated from the condensation of 1 and 3. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2143-2145, 1997

Additional Material: 2 Tab.

Type of Medium: Electronic Resource

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

hits 1 - 5 | 5 hits