Thermoplastic compositions are described that exhibit resistance to hydrocarbon absorption. Methods for forming the thermoplastic compositions are also described. Formation methods include combining a polyarylene sulfide with a first impact modifier and a second impact modifier such that the impact modifiers are dispersed throughout the polyarylene sulfide. A crosslinking agent can be combined with the other components of the composition following dispersal of the additives throughout the composition to dynamically crosslink at least one of the first and second impact modifiers.

A composite drill pipe including an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The plurality of flow channels are formed by a plurality of walls extending radially between an outer diameter of the inner pipe and an inner diameter of the outer pipe. A method of forming a composite drill pipe includes pultruding a drill pipe comprising an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The method also includes providing a multi-directional reinforcement over an outer diameter of the outer pipe.

A composite drill pipe including an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The plurality of flow channels are formed by a plurality of walls extending radially between an outer diameter of the inner pipe and an inner diameter of the outer pipe. A method of forming a composite drill pipe includes pultruding a drill pipe comprising an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The method also includes providing a multi-directional reinforcement over an outer diameter of the outer pipe.

A catheter includes a balloon and a shaft having a coaxial portion including an outer tubular member having a bore, a transition neck, an access fitting adjacent the proximate end of the catheter shaft for directing a guidewire into the catheter shaft, an inflation port, a guidewire tubular member disposed coaxially in the outer tubular member, the outer tubular member and guidewire tubular member defining a first, annular inflation/deflation lumen fluid communication with the inflation port, at least one second inflation/deflation lumen separate from and non-coaxial with the guidewire tubular member and having a cross-sectional area less than the cross-sectional area of the first inflation/deflation lumen and opening at a proximate end into the first inflation/deflation lumen and at the distal end of the transition neck.

A catheter includes a balloon and a shaft having a coaxial portion including an outer tubular member having a bore, a transition neck, an access fitting adjacent the proximate end of the catheter shaft for directing a guidewire into the catheter shaft, an inflation port, a guidewire tubular member disposed coaxially in the outer tubular member, the outer tubular member and guidewire tubular member defining a first, annular inflation/deflation lumen fluid communication with the inflation port, at least one second inflation/deflation lumen separate from and non-coaxial with the guidewire tubular member and having a cross-sectional area less than the cross-sectional area of the first inflation/deflation lumen and opening at a proximate end into the first inflation/deflation lumen and at the distal end of the transition neck.