| 摘要 |
<p>The present invention provides a process for preparing branched chain, thermoplastic polymers having improved melt strength and die swell properties. This process comprises reacting at least one thermoplastic polymer capable of reaction with an epoxy or isocyanate functionality, the polymer being in the molten state, with at least one branching agent selected from the group consisting of epoxy containing at least two epoxy groups per molecule of epoxy branching agent, and isocyanate containing greater than two isocyanate groups per molecule of isocyanate branching agent, to produce branched chain thermoplastic polymers having a melt strength ratio of T2/T2 of less than about 2.0 at 235.degree.C. The molten, thermoplastic, branched chain polymer reaction product has increased melt strength and intrinsic viscosity. The increased molt strength polymers also have improved die swell characteristics and are useful in extrusion applications such as blow molding.</p> |
