Molecular Weight Changes and Network Formation by Scission and Crosslinking -- Main Chain Scission of Polymers -- Crosslinking -- Random Crosslinking -- Enhanced Crosslinking -- Other Forms of Crosslinking -- Combined Crosslinking and Scission -- Antioxidants -- Fillers -- Crosslinking of Polymers in Solution -- References -- High Energy Radiation-and UV Light-Induced Crosslinking and Chain Scission -- Importance of Radiation-Induced Crosslinking and Main-Chain Scission in Linear Polymers -- Types of Radiation and Radiation Sources -- Absorption of Radiation -- General Aspects Concerning XL and CS in Linear Polymers -- Random and Specific Site Attacks -- Detection of XL and CS -- Simultaneous XL and CS Mechanisms -- Ion Beam-Induced Radiation Effects in Linear Polymers -- X-Ray-Induced Radiation Effects in Linear Polymers -- References -- Main-Chain Scission of Linear Polymers as Studied by Pulse Radiolysis and Flash Photolysis -- Studies on the Dynamics of Macromolecules in Solution -- Studies Concerning Intramolecular Interactions -- Studies Concerning Preferential Solvation -- Studies Concerning the Dynamics of Polynucleotides -- Detachment of DNA Double Strands -- Lifetime of Salt Bridges -- Concluding Remarks -- References -- Carbon 13 NMR of Gamma-Irradiated Polyethylenes -- Carbon 13 NMR of Polyethylene -- Severe Melt Processing of Polyethylene -- Irradiation of Polyethylene-Solution NMR -- Carbon 13 NMR of n-Hexatriacontane -- Carbon 13 NMR Spectra of NBS 1475 before and after 60Co Gamma Irradiation -- Carbon 13 NMR Spectra of Marlex 6003 before and after 60Co Gamma Irradiation -- Irradiation of Polyethylene-NMR of the Solid State -- Summary -- Acknowledgements -- References -- The Use of Pulsed NMR to Determine Network Formation by Crosslinking and Entanglement -- References -- Methods for Studying the Effects of High-Energy Irradiation on the Mechanical and Electric Properties of Polymers -- Mechanical Properties -- Modulus and Compliance -- Ultimate Mechanical Properties -- Recovery -- Electrical Properties -- Multiple Transitions and Molecular Mobilities -- Physical Ageing -- Experimental Technique and Examples -- Time-Domain Techniques -- Frequency-Domain Methods -- Temperature-Domain Methods -- Thermally Stimulated Electrical Current-Fluctuations -- Conclusions -- References -- Thermally Stimulated Discharge and Dielectric Measurements of Cure in Resins and Gelled Materials -- Influence of Gelation of Polar Media -- Interfacial Regions in Copolymer Systems -- Phase Separation Processes -- Conclusion -- Recommended Reading -- Ultrasonic and Viscoelastic Studies of Chain Entanglement in Polymer Solutions -- Dynamic Properties of Isolated Polymer Chains in Solution -- Ultrasonic Relaxation Measurements on Polymer Solutions -- Viscoelastic Processes -- Ultrasonic Studies of Entangled Polymer Systems -- Phase Separation in SBS Solutions -- Ultrasonic Studies of Network Formation in Rigid Networks -- Recommended Reading -- Specific Papers -- Determination of Cross-Link Density in Amorphous Networks by Stress-Strain-Swelling Experiments -- Molecular Constitution of a Network -- Macroscopic Deformation -- Microscopic Deformation -- The Elastic Free Energy of the Single Chain and the Network -- The Affine Network Model -- The Phantom Network Model -- Stress-Strain Relations for the Phantom and Affine Network Models in Simple Tension -- The Constrained Junction Theory of Networks -- Determination of the Degree of Cross-Linking by Equilibrium Swelling Measurements -- Numerical Example of Cross-Link Density Calculation -- Deviations From Ideal Network Behavior -- Conclusions and Discussion -- References -- Formation and Properties of Thermosetting and High Tg Systems -- The Time-Temperature-Transformation (TTT) Isothermal Cure Diagram -- Anomalous Properties Versus Extent of Cure -- The Continuous Heating Time-Temperature-Transformation (CHT) Cure Diagram -- Linear Polymerization and the TTT Diagram -- Solvent-Based Reactive Systems and the TTT Diagram -- The Glass Transition Temperature, Tg, as a Characterizing Parameter for Reactive Systems -- Torsion Pendulum (TP) and Torsional Braid Analysis (TBA): Techniques for Characterizing the Cure and Properties of Thermosetting Systems -- TP/TBA-Modes -- Instrumentation -- Applications -- Acknowledgement -- References -- Dynamic Shear Compliance of Polymer Melts and Networks -- The Master Curve and its Analysis -- The Meander Superstructure and its Shear Deformation Modes -- Viscoelasticity of Polymer Fractions and Binary Blends in the Melt -- The Shear Compliance of Polymer Networks in Dependence on Crosslink Density -- The Glass Relaxation Process -- The Shearband Process -- The Effect of Filler on the Dynamic Shear Compliance -- Conclusion -- Acknowledgement -- References -- Paraelasticity of Organic Colloid Systems -- Paraelastic Relaxation Strength -- Clay Organic Complexes -- Oriented Stacks of Lipid Lamellae -- The n-alkanes in the Waxy State -- Polymer Melts and Networks in the Rubbery State (plateau compliance) -- Conclusion -- Acknowledgement -- References -- The Use of Size Exclusion Chromatography in the Studies of Crosslinking and Chain Scission in Polymers -- Chain Scission -- Crosslinking -- References.