Theory of Flexible Polymer Networks: Elasticity and Heterogeneities

Round 1

Reviewer 1 Report

The article by Sergey Patyukov provides readers with an interesting theoretical overview of the main existed elasticity models of flexible polymer networks. Despite many efforts done more than half-century history, at present the theory of polymer network elasticity still have many unanswered questions. The Author tried to bridge the gap between the main developed approaches, which allowed to give answers to some of these questions. The article certainly deserves publication in Polymers journal because it has a clear and consistent presentation of main efforts in the considered subject. The author gives many useful references, among which many articles with his participation.

I have only one recommendation. It is well known from experimental studies that the scattering intensity increases by introducing cross-links due to cross-linking heterogeneities. It would be nice if Author discusses how random heterogeneity of polymer networks might be taken in to account.

Author Response

In accordance with the Reviewer 1 wishes, I included an additional section discussing the theory of heterogeneity in polymer networks and related experiments. Since this led to an increase in text size and the number of formulas, I added a table of contents and also introduced independent numbering of equations in each section. As a result of these changes, the earlier title of the article ceased to be optimal and changed to "Theory of flexible polymer networks: elasticity and heterogeneities"

Reviewer 2 Report

The manuscript clearly introduces the presented review of available models to describe the mechanical properties of polymer network materials and continues to discuss each of the models.

The merit of the review is unclear, especially considering the discussion is very brief. The limitations and applicability constraints of the different models need to be highlighted and compared.

What is the added value of this review compared to earlier work describing models and reviews of models?

Who is “we” if there is only 1 author credited? Credit the other authors if there are any.

The discussion should be expanded. In the current manuscript the discussion is a brief point-by-point summary of the content of the manuscript, rather than a discussion. The discussion section should discuss the assumptions made to construct the models and the limitations thereof in a comprehensive comparison.

Author Response

In accordance with the wishes of the Reviewer 2, I removed the "we" appeal from most of the text and significantly expanded the "Discussion" section by discussing the results and applicability conditions of the models under consideration. Also, as "added value of this review", a parallel discussion of the theory and experiments on inhomogeneities in the network is given. In addition, a significant part of the considered models of the network elasticity are new and first reviewed in this paper.

Reviewer 3 Report

The author presents a good written overview of  of the main elasticity models of flexible polymer networks and proposes a generalization of this model to describe the crossover between the entangled and phantom regimes of a swollen network. He also obtained the dependence of the Mooney Rivlin Parameters on the polymer volume fraction and shows that these are in agreement with experiments. I have nothing to object in the review part of this manuscript and in the proposed generalization of the  theory. For my personal view, a discussion section is somewhat too short. In fact, it stops at the point, where it becomes particularily interesting. At the end of the Discussion Section, the author makes several questions to be adressed in the future and says that this list is not complete. There are no restrictions on the length of the article in this journal. Therefore, I suggest to expand the discussion section by posing more questions and discussing the arising problems in the existing theories and possible ways to solve them. Is there some controversy in the interpretation of some data? I believe that such a modification would make this very interesting paper more influencial.   

Author Response

In accordance with the wishes of Reviewer 3, I significantly expanded the "Discussion" section, as well as the range of questions "to be addressed in the future".