Shape-Memory Polymers Based on Carbon Nanotube Composites

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The review written by da Silva and colleagues concerns a very specific type of CNT composites, i.e. shape-memory composites. The proposed work can be considered a comprehensive overview of the research conducted over the past years on the design and production of SMP/CNT composites based on both thermoset and thermoplastic matrices. The manuscript is logically divided into very accurate and absolutely comprehensive sections. The technical quality of this work can be considered as very good. An undoubted advantage of the manuscript is the fact that the text is accompanied by photographs, diagrams, and comparative tables. In my opinion, this contribution provides valuable perspective on the scientifically important area of research and will attract a wide range of readers. I have just one concern. The authors frequently use abbreviations. Given the length of the work, a list of abbreviations could be helpful for the reader. Of course, all designations are explained within the text, but finding one sometimes requires an excessively long search through the text. In my opinion index of acronyms and abbreviations used in the text can improve the readability.

Comments on the Quality of English Language

Minor editing of English language required. 

Author Response

The authors are thankful for the revision and the positive opinion. The reviewer is quite right, a list of abbreviation should be included. We included the following list of abbreviations:

Abbreviations List:

ABS - Acrylonitrile butadiene styrene

AFM - Atomic Force Microscopy

AR - Acrylic Resin

BR - Benzoxazine resin

CAD - Computer-aided design

CB - Carbon black

CE - Cyanate ester

CF - Carbon fiber

CNSL - Cashew nut shell liquid

CNT - Carbon nanoubes

CTE - Coefficient of thermal expansion

CW - Carnauba wax

DA - Dopamine

DLP - Digital Light Process

EM - Electromagnetic

EOC - Ethylene-α-octene copolymer

EPAc - Epoxy Acrylate

ER - Epoxy resin

ESO - Epoxidized soybean oil

et-SMP - electrothermal shape-memory polymer

EUG - Eucommia ulmoides gum

EVA - Poly(ethylene-co-vinyl acetate)

fCNT - Functionalized carbon nanotubes

FDM - Fused Deposition Modeling

fMWCNT - Functionalized multi-walled carbon nanotubes

fu - furan grafted

Gr - Graphene

HBPU - Hyperbranched Polyurethane

hCNT - hybrid carbon nanotubes

hMWCNT - Hybrid multi-walled carbon nanotubes

hSWCNT - Hybrid single-walled carbon nanotubes

IR - Infra-red

LCE - Liquid crystal elastomers

LDPE - Low-density polyethylene

mPE-g-AA - Acrylic acid-functionalized metallocene polyethylene

MW - Microwave

MWCNT - Multi-walled carbon nanotubes

NIR - Near infra-red

NR - Natural Rubber

P(AM-co-OA) -Poly(acrylamide-octadecyl acrylate)

PAEK - Polyaryletherketone

PANI - Polyaniline

PBS - Poly(butylene succinate)

PCL - Poly(ϵ-caprolactone)

PCL-Py - Pyrene containing Poly(ϵ-caprolactone)

PCO - Polycyclooctene

PE - Polyethylene

PEG - Polyethylene glycol

PEGDMA - Polyethylene glycol dimethacrylate

PEO - Polyolefin elastomer

PEU - Polyester urethane

PK - Polyketone

PLA - Poly(lactic) acid

PNIPAAm - Poly(N-isopropylacrylamide)

POE - Poly(ethylene-co-octene)

POP - Palm oil polyol

PPC - Poly(propylene) carbonate

PS - Polystyrene

pt-SMP - Photothermal shape-memory polymer

PU - Thermoset polyurethane

PVA - Polyvinyl alcohol

PVC - Polyvinyl Chloride

PVDF - Polyvinylidene fluoride

PW - Paraffin wax

rDA - retro Diels-Alder

RF - Radio frequency

Rf - Shape fixity ratio

rGO - Reduced graphene oxide

RPSM - Reversible plasticity shape-memory

Rr - Shape recovery ratio

SBS - Poly(styrene-β-butadiene-β-styrene)

SIS - Poly(styrene-β-isoprene-β-styrene)

SLA - Stereolithography

SME - Shape-memory effect

SMP - Shape-memory polymers

SWCNT - Single-walled carbon nanotubes

TC - Thermal conductivity

Tg - Glass transition temperature

Tm - Melting temperature

TPI - Trans-1,4- polyisoprene

TPU - Thermoplastic polyurethane

t-SMP - Thermal responsive shape-memory polymer

Ttrans - Transition temperature

UHMWPE - Ultra High Molecular Weight Polyethylene

UV - Ultra-violet

Vis - Visible

Reviewer 2 Report

Comments and Suggestions for Authors

The authors conducted a very comprehensive review of research carried out in recent years on the production of SMP/CNT composites using both thermoset and thermoplastic matrices. The review focused on the distinct contributions of CNT to the nanocomposite's response to external stimuli.

1. The review is well-written

2. The title accurately represents the content of the paper.

3. The abstract adequately summarizes the study.

4. The introduction adequately provides a brief overview of the topic, including its significance and relevance in the field.

5. The introduction and literature review are well-explained.

6. The review is well organized into thematic sections or subtopics, where the authors have summarized the key findings from the literature

7. Tables and figures clearly and effectively present data visually and are easy to understand.

8. The conclusion summarizes the main findings and insights from the review. The applications of SMP/CNT composites in various fields are well highlighted, including robotics, medical engineering, and MEMS.

9. The authors mentioned briefly life cycle assessment and sustainability in the conclusion. It would be interesting to expand on specific sustainability challenges and how they can be addressed.

 

9. The article is adequately referenced. 

Author Response

The authors are thankful for the revision and the positive opinion. The reviewer is quite right, there is a long way to go, before these composites are produced within a sustainability framework. This topic is challenging, there is so much that can be done, and that should be planned. We expanded a little on the topic, including the sentence:

“Furthermore, addressing critical challenges in improving processing routes by moving towards solvent-free approaches and developing novel methods to facilitate processing of natural polymers and the dispersion of particulate fillers is crucial for the sustainability of these materials. In addition, the recycling of SMP/CNT presents a challenge for developing more eco-friendly options that benefit from the unique properties of CNT.”