Shades of Green: Life Cycle Assessment of a Urethane Methacrylate/Unsaturated Polyester Resin System for Composite Materials

Round 1

Reviewer 1 Report

This is an interesting paper of potential interest to readers of the journal, but is somewhat compromised by the limited detail (commercial confidentiality) of the material presented!

In the first paragraph of the introduction, it could be useful to include the definitions pertinent to "bio-plastics" presented Reddy et al  in https://doi.org/10.1016/j.progpolymsci.2013.05.006.

When "cradle-to-cradle" is introduced, the book by Braungart and McDonough might be a useful reference?

At Section 1.4, a list/table of prominent refined bio-mass precursors would be very useful?

I'm surprised that the authors do not reference their former colleagues' (Azapagic and Hamerton) books where tractable methods for dealing with environmental impacts were presented.  

The paper authors do not address Non-Renewable/Abiotic Resource Depletion or Land Use (BS8095) as environmental impacts?

POCP is normally photochemical oxidant creation potential!

At section 4.2, it may be appropriate to mention the Liquid Composite Molding (RTM/RIFT) and in-mould gel-coating processes as routes to achieving significantly lowered VOC emissions?

line 269: "to be" is unnecessary?

line 351: "resin system resin"

lines 392-2: "the Resin  resin system's mass"

lines 424-5: is there a reference for "contributions from fertilisers and harvesting are comparable to extraction from the ground"

reference 7: not Mr E Commission ;-)

reference 10: editor = KL Pickering

Figure 3 caption: "against against"

table 1: three rows of data but only two materials listed?

Table 2: {bold} might be preferable to {red} for those viewing in back and white!

Author Response

In the first paragraph of the introduction, it could be useful to include the definitions pertinent to "bio-plastics" presented Reddy et al  in https://doi.org/10.1016/j.progpolymsci.2013.05.006.

    -> Added, with comment.

When "cradle-to-cradle" is introduced, the book by Braungart and McDonough might be a useful reference? 

    -> Added.

At Section 1.4, a list/table of prominent refined bio-mass precursors would be very useful?

    -> We are not sure how useful this would be given the range of precursors that are available.

I'm surprised that the authors do not reference their former colleagues' (Azapagic and Hamerton) books where tractable methods for dealing with environmental impacts were presented. 

    -> a recommendation of this book as useful pre-reading has been added in section 1.2.

The paper authors do not address Non-Renewable/Abiotic Resource Depletion or Land Use (BS8095) as environmental impacts? 

    ->  a comment on this has been added.

POCP is normally photochemical oxidant creation potential! -> corrected

At section 4.2, it may be appropriate to mention the Liquid Composite Molding (RTM/RIFT) and in-mould gel-coating processes as routes to achieving significantly lowered VOC emissions?

    -> A comment to this effect has been added.

Reviewer 2 Report

The manuscript provided a critical review on life assessment of polymer resin based composites. The work is interesting and the manuscript is generally well written. This submission can be considered for publication after a moderate review based on the comments below:

1.   Title needs to be revised reflecting specific polymer resins used in this study instead of being very general.

2.   Abstract has unnecessary general information (first few sentences). The abstract should be modified showcasing what this manuscript is about concisely.

3.   Novelty this particular work on LCA should more efficiently conveyed. What adds new knowledge from this study compared to existing literature?

4.   The subsections in every main section are too many and are not quite traditional. I would suggest to have standard sub-sections/titles to improve the flow.

5.   2.The general style of the paper is quite informal and somewhat coumsy. This is not recommended in a journal publication, not only from a stylistic point of view but also (and more importantly) as it negatively impacts the clarity of the paper. Again my main concern was, the flow between each section is somewhat disjointed. It is a useful work but authors should bring the information close together and present them efficiently. Please carefully revise this aspect.

Other minor correction to be made:

1.   Use of capital letter is inappropriate. Thoroughly check thought the manuscript.

2.   Acronyms should be mentioned at their first mentions.

Author Response

1. Title needs to be revised reflecting specific polymer resins used in this study instead of being very general.

    -> The title has been modified to “Shades of Green: Life Cycle Assessment of a Urethane Methacrylate/Unsaturated Polyester Resin System for Composite Materials”

2.   Abstract has unnecessary general information (first few sentences). The abstract should be modified showcasing what this manuscript is about concisely. 

    -> The Abstract has been revised.

 3.   Novelty this particular work on LCA should more efficiently conveyed. What adds new knowledge from this study compared to existing literature? 

    -> A comment regarding the novelty arising from the methodology has been added to the text and to the abstract.

4.   The subsections in every main section are too many and are not quite traditional. I would suggest to have standard sub-sections/titles to improve the flow.

    -> The structure of the paper has been revised with a number of subsection titles being removed.

5.   2.The general style of the paper is quite informal and somewhat coumsy. This is not recommended in a journal publication, not only from a stylistic point of view but also (and more importantly) as it negatively impacts the clarity of the paper. Again my main concern was, the flow between each section is somewhat disjointed. It is a useful work but authors should bring the information close together and present them efficiently. Please carefully revise this aspect. 

    -> We thank the reviewer for raising this issue.  On rereading the document we have realised that the presentation is somewhat colloquial in places, perhaps stemming from the mix of subject areas covered by the authors.  We have revised the text in a number of places, removing any ambiguity or informality.  For example the comment on ‘tweaking’ the formulation has been changed to “The latter is significant as commercial resin systems are frequently modified at the request of the customer in order to meet a specific criteria whilst maintaining the overall performance of the base resin system.”

Other minor correction to be made:

1.   Use of capital letter is inappropriate. Thoroughly check thought the manuscript.

2.   Acronyms should be mentioned at their first mentions.

On the basis of these two comments the entire document has been carefully examined and changes made.

Round 2

Reviewer 2 Report

The revised manuscript has been improved. However, please pay attention to the following:

1.   Figure 2 and its labels are not properly arranged.

2.   Still, there are capital letters being used between words, in throughout the manuscript; for example, lines 240 to 247. Particularly, axes titles in graphs/plots and tables heads.

3.   Keywords should not be just abbreviated. Expand LCA.

4.   Section 1.2- Why green is apostrophised? It should be just Green Composites.

5.   Some section headings are given with first letter of the words being capital and some are not.

6.   Section 3.1 title is unnecessary. Remove ‘overview’. It does not make any sense.

Author Response

1.   Figure 2 and its labels are not properly arranged. -> Formatting glitch addressed.

2.   Still, there are capital letters being used between words, in throughout the manuscript; for example, lines 240 to 247. Particularly, axes titles in graphs/plots and tables heads.

-> Having reviewed the text carefully, with particular attention to the lines specified, I believe that you are referring to the labelling of the resin system, R, and two different additions, A1 and A2.  These are referred to throughout the text and within the figures.  If this is not the case then I am very happy to look at this again, although it would be helpful to have a specific example to understand what the issue is.

3.   Keywords should not be just abbreviated. Expand LCA. -> Done

4.   Section 1.2- Why green is apostrophised? It should be just Green Composites. -> Done

5.   Some section headings are given with first letter of the words being capital and some are not. -> The section titles have been revised.

6.   Section 3.1 title is unnecessary. Remove ‘overview’. It does not make any sense. -> This would create a hanging paragraph which is contrary to the British Standard on Report Writing.