摘要:
Polyesters of para-oxybenzoyl are infusible and very resistant to acids and solvents, thus limiting the means by which such polymers can be fabricated. Such a polyester is made more amorphous, thus improving compression moldability, by subjecting it to a high temperature treatment, followed by a rapid quench. The resulting polymer has reduced crystalline orientation, as evidenced by X-ray diffraction patterns, and molded articles thereof have improved flexural strength, without adversely affecting the modulus. The thermal treatment is carried out on the polymer by heating at a temperature of at least 300.degree.C, and up to just below the decomposition temperature of the polymer, followed by quenching of the hot polymer.
摘要:
High modulus oxybenzoyl copolyester fibers are produced by heating to an elevated temperature and stretching oxybenzoyl copolyesters fibers having molecular weights in the range of from 2,000 to 200,000 and melting points of at least 250.degree.C and comprising recurring moieties of Formulas I, II and III - ##SPC1##wherein n is 0 or 1; x, y and z are integers; y:z = from 10:15 to 15:10, x:y and x:z = from 1:100 to 100:1; x + y + z = from 30 to 600; the carbonyl group of Formula I is meta and/or para to the oxy group thereof; the carbonyl groups of Formula II are meta and/or para to each other; and the oxy atoms of Formula III are meta and/or para to each other; and in more than 50% of the total of sid moieties having said mentioned groups therein they are of para configuration. For Formulas I and II n is preferably 0 and for Formula III it is usually 1.
摘要翻译:通过加热至高温制备高模量羟基苯甲酰基共聚酯纤维,并拉伸分子量范围为2,000至200,000,熔点至少为250℃并含有式I,II和III的重复部分的氧代苯甲酰基共聚酯纤维, 其中n为0或1; x,y和z是整数; y:z = 10:15〜15:10,x:y,x:z = 1:100〜100:1; x + y + z = 30〜600; 式I的羰基是其氧基的间位和/或对位; 式II的羰基是彼此的间位和/或对位的; 并且式III的氧原子彼此是间位和/或对位的; 并且在其中具有所述组的sid部分的总数的50%以上是它们的对位构型。 对于式I和II,n优选为0,对于式III,其通常为1。
摘要:
Partially crosslinked thermoplastic polyesters of recurring linear moieties of the formula ##SPC1##Are described wherein n is 0 or 1, and p, q and r are integers which total 30 to 600. The polyester is partially crosslinked by oxidizing meltable polymer to a "gelled" thermoplastic state, producing molecules of average molecular weights in the range of 10,000 to 1,000,000, preferably of 100,000 to 500,000.
摘要:
The production of oxybenzoyl polyesters is facilitated by the incorporation of a phosphite, particularly an organic phosphite, during the production enabling the production of molded articles from these polyesters of improved appearance and excellent properties.
摘要:
The molding properties of molding compounds based on wholly aromatic polyesters are improved by the addition to such wholly aromatic polyester compositions of a minor amount of an aromatic polyester which is a combination of the following units: ##STR1## Where; p=0 to 0.9, q=0.1 to 1.00, r=1 to 7, S=0.3 to 1.00, t=0 to 0.7. A preferred formulation consists of a polyester where the units are: p=0, q=1.0, r=1 to 5 and S=1.0.
摘要:
Compositions comprising liquid crystalline polymer; inert filler; and small particle size filler having a mean particle size less than about 50 nanometers. These blends have excellent adhesion and low surface roughness properties and can be used as molded articles in electronics or electrical applications.
摘要:
Excellent mold release coupled with a good retention of mechanical properties (i.e., flexural strength and flexural modulus) is made possible in the liquid-crystal polyester resin composition of the present invention, which comprises: a) 35-85 wt. % of a wholly aromatic polyester which is melt processable and which displays anisotropy in the molten state; b) 15-65 wt. % of a platelet-shaped filler having a mean particle size of less than 5 microns; and c) optionally, up to 20 wt. % titanium dioxide.
摘要:
Polymer compositions containing a polyphenylene etherpolyolefin copolymer are obtained by reactive melt mixing olefin-(alkyl)acrylic acid copolymer with a polyphenylene ether and a carboxylic anhydride. The compositions are used in many commercial applications requiring high temperature resistance including formation of films, fibers and molded articles with excellent surface appearance.