Abstract:
A thermotropic liquid crystalline polymer composition capable of exhibiting both a low melting temperature and good heat resistance without the use of conventional naphthenic acids is provided. The melting temperature may, for example, range from about 250° C. to about 400° C. Even at such low melting temperatures, the present inventors have surprisingly discovered that the ratio of the deflection temperature under load (“DTUL”), a measure of short term heat resistance, to the melting temperature may remain relatively high. The specific DTUL values may range from about 200° C. to about 300° C. The ability to form a polymer composition with the properties noted above may be achieved, at least in part, by the use of an aromatic amide oligomer.
Abstract:
A method for making a polystyrene ionomer comprises: preparing a metallic comonomer within styrene monomer to form a reaction mixture; and placing the reaction mixture under conditions suitable for the formation of a polymer composition. The metallic comonomer can be a metal acrylate, formed by contacting a metal complex and an acrylate precursor.
Abstract:
A liquid crystalline polymer composition that contains a liquid crystalline polymer and an aromatic amide oligomer is provided. The oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix under shear. The oligomer is also not easily volatized or decomposed during compounding, molding, and/or use, which minimizes off-gassing and the formation of blisters that would otherwise impact the final mechanical properties of a part made from the polymer composition. While providing the benefits noted, the aromatic amide oligomer does not generally react with the polymer backbone of the liquid crystalline polymer to any appreciable extent so that the mechanical properties of the polymer are not adversely impacted.
Abstract:
Described herein are composites that inhibit or reduce adhesion between two or more tissues. Also described herein are methods of using the composites.
Abstract:
An olefin polymerization catalyst may be prepared using a process including contacting a metal compound of the formula M(OR1)2 with a diketone to form a catalyst precursor having the general formula: wherein M is a Group IIA metal; O is oxygen; n=1 or 2; R1, R2, R3, and R4 are the same or different; and are a hydrogen or a substituted or unsubstituted alkyl or aryl moiety having from about 1 to about 20 carbons atoms.
Abstract translation:可以使用包括使式M(OR1)2的金属化合物与二酮接触以形成具有以下通式的催化剂前体的方法来制备烯烃聚合催化剂:其中M是IIA族金属; O是氧; n = 1或2; R1,R2,R3和R4相同或不同; 并且是具有约1至约20个碳原子的氢或取代或未取代的烷基或芳基部分。