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Question:

Is the degree of crosslinking equal to the degree of curing in the process of resin curing?

Is the degree of crosslinking equal to the degree of curing in the process of resin curing?

Answer:

Swelling equilibrium methodCrosslinked polymer because of its internal network cannot be dissolved in the solvent swelling, but can produce a certain degree of crosslinking degree of swelling in the network depends. The three-dimensional network into polymer cross-linking solvent molecules into, will cause the network to stretch the three-dimensional molecular crosslinked system. Volume expansion of network extension leads to reduced between crosslinking points of polymer chain conformation entropy, so that the crosslinking network generates elastic contraction, the average molecular contraction force depends on the size of the crosslinked polymer two cross-linking point between the polymer chain segment value. When the solvent swelling contraction force and cross-linked segments of phase equilibrium when the system reached equilibrium swelling state. When measured the swelling degree of Q value, you can calculate the average molecular chains of polymer cross-linking points between values. Obviously, the greater the value, that the crosslinking degree of cross-linked polymer is smaller (AC The smaller the joint density is
Crosslinking degreeIn the branched polymer, with no chemical bond between the branches in theory. Their structure is still similar to the linear polymer can be dissolved and melted. But when formed between the side of the same or different polymer chains covalently attached, the polymer network like structure. The network depends on the size of the polymer chain the number of chemical bonds between the polymer can be cross-linked. Independent network formed by crosslinking supramolecular. Two independent interpenetrating network called IPN polymer and crosslinking non crosslinked interpenetrating network called semi interpenetrating network polymer, the molecular rotation and movement is limited, and thus improve the the strength of polymer on the macroscopic and stiffness. In addition, crosslinked polymer material also has a "memory effect". When a high enough degree of crosslinking polymers are stretched, crosslinking The chain blocks the slippage between the chains and the segments are only stretched. But when the external force is removed, the chain reverts back to its original location. Vulcanized rubber is an intuitive example of the change in properties of polymers after crosslinking and has a "memory effect"
The thermosetting polymer system, the curing reaction degree of crosslinking after cross-linking point between the polymer chain length (i.e. crosslink density) data, curing system and material selection in the design, selection and preparation of curing conditions after performance thermosetting materials are closely related. In order to get the best performance of thermosetting polymer materials the selection process of thermosetting polymer material of the optimum reaction degree of cross-linking degree and curing need. It can be said that is consistent with both reflect.

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