摘要:
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.
摘要:
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.
摘要:
Described herein are composites that inhibit or reduce adhesion between two or more tissues. Also described herein are methods of using the composites.
摘要:
An M-ary signal constellation within an N-dimensional space is defined, preferably such that each of the M symbols reside upon the surface of an N-dimensional sphere and such that a minimum distance between symbols is maximized. N orthogonal functions are used as the bases for representing the N-dimensional symbols for transmission. Orthogonal functions exhibiting orthogonality in frequency, time and/or space are also described for this purpose. Furthermore, conventional QAM symbol encoding may be used to represent the N-dimensional symbols, thereby facilitating the use of conventional modulation techniques. In this manner, higher dimensional modulation schemes may be realized.
摘要:
A thermotropic liquid crystalline polymer melt polymerized in the presence of a viscosity modifier that can help increase the “low shear” viscosity of the resulting composition is provided. The increased “low shear” viscosity can minimize drooling of the polymer composition during processing and also allow it to possess a greater melt strength, which facilitates its ability to be processed in a wide variety of applications without losing its physical integrity. Despite having a relatively high “low shear” viscosity, the present inventors have discovered that the viscosity modifier does not substantially increase the “high shear” melt viscosity of the polymer composition. In this regard, the ratio of the “low shear” viscosity to the melt viscosity is generally very high, such as within a range of from about 50 to about 1000.
摘要:
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.
摘要:
An aromatic amide compound having the following general formula (I) is provided: wherein, X1 and X2 are independently C(O)HN or NHC(O); G1, G2 and G3 are independently hydrogen, C(O)HN-phenyl, or NHC(O)-phenyl, wherein at least one of G1, G2 and G3 is C(O)HN-phenyl or NHC(O)-phenyl; Q1, Q2, and Q3 are independently hydrogen, C(O)HN-phenyl, or NHC(O)-phenyl, wherein at least one of Q1, Q2, and Q3 is C(O)HN-phenyl or NHC(O)-phenyl; R5 is halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, or heterocyclyl; and m is from 0 to 4.