Preparation and Characterization of Polyethylene Biocomposites Reinforced by Rice Husk: Application as Potential Packaging Material

Round 1

Reviewer 1 Report

Manuscript entitled “Preparation and Characterization of Polyethylene biocomposites reinforced by rice husk: application as potential packaging material”. This manuscript describes preparation of packaging films using plyethylene blended with different ratios of rice husk (RH). The properties of the obtained films were characterized by different techniques. Also biodegradation of the developed films as well as the respiration dynamics of apples, were studied. The work demonstrated significant results, but there are few comments:

• The preparation of the blends was done without addition of plasticizer or compatiblizer although high amounts of RH was added (up to 50%). This should have passive effect on the mechanical properties of the formed films (tensile strength and elongation) which are not studied here although the mechanical properties is very important for a packaging material, can you comment on that?
• - Also, SEM imaging is required to show morphology of the films, I believe a phase separations will appear in such combination.
• - There are some language mistake which should be corrected before publication such as in line 46 “biopolymers have been received considerable…” been should be deleted. Line 54 “Incorporation of natural filler in polymer matrix have been found..” have should be “has”. And many others.

Author Response

The authors acknowledge all reviewer benevolent comments and suggestions.

The corrections and answers to the reviewer are given as follows:

 

Manuscript entitled “Preparation and Characterization of Polyethylene biocomposites reinforced by rice husk: application as potential packaging material”. This manuscript describes preparation of packaging films using plyethylene blended with different ratios of rice husk (RH). The properties of the obtained films were characterized by different techniques. Also biodegradation of the developed films as well as the respiration dynamics of apples, were studied. The work demonstrated significant results, but there are few comments:

 

• The preparation of the blends was done without addition of plasticizer or compatiblizer although high amounts of RH was added (up to 50%). This should have passive effect on the mechanical properties of the formed films (tensile strength and elongation) which are not studied here although the mechanical properties is very important for a packaging material, can you comment on that?

 

Generally, the compatibilizer can be used to avoid phase separation between matrix and filler and to promote an better interfacial adhesion for improved mechanical properties.

In this work we didn't use compatibilizer, but this is  a good idea for further investigations.

 

We included the results of mechanical properties in the manuscript (3.8. Mechanical properties of the LDPE/RH biocomposite)  , thank you for your suggestion.

 

 

• - Also, SEM imaging is required to show morphology of the films, I believe a phase separations will appear in such combination.

 

In Figure 1 we can nicely see the distribution of RH within the LDPE matrix so we are instead of SEM, used A Olympus model BX50 light microscope ( Olympus Optical Co. Ltd., Japan)  and as you assumed the phase separation occurs in LDPE/RH biocomposites especially at a higher RH content.

We included this results of OM in the manuscript, Figure 2 and we hope so that this will be good for explanation the phase separation in this LDPE/RH system.

 

• - There are some language mistake which should be corrected before publication such as in line 46 “biopolymers have been received considerable…” been should be deleted. Line 54 “Incorporation of natural filler in polymer matrix have been found..” have should be “has”. And many others.

 

Corrections made directly in the paper.

 

Prof. Emi Govorin Bajsic, PhD

Author Response File: Author Response.pdf

Reviewer 2 Report

Emi Govorcin Bajsic and co-workers submitted the manuscript entitled “Preparation and Characterization of Polyethylene biocomposites reinforced by rice husk: application as potential packaging material”, to be published in “Chemistry”. In this paper, author described the uniqueness of LDPE/RH biocomposites as food packaging material. Overall, this is a nice work, thus can be published after addressing the queries.

1. In the introduction, author must provide the importance of rice husk towards the development of bio-degradable polymers. Author also needs to cite the following references; 1. Polymers 2021, 13, 2391 and 2. Polymers 2021, 13, 104.
2. For Figures 4, 5 and 6, author must state the number of experiments (n=?) conducted to collect the data with error bars. Also deliver n=? in Figure 7.
3. Provide the Table for FTIR stretching frequencies or enhance the explanation.
4. Why only used RH up to 50% wt, what happens above 50% wt?
5. Explanation for mechanism must be enhanced for the readers.
6. Please provide the SEM instrument model as well as the microscopy used in soil-burial test.
7. Many sections, the explanation seems to be deficient, it should be rectified in the revision. Figures resolution should be enhanced and their captions must be re-written with informative and meaningful.

Author Response

The authors acknowledge all reviewer benevolent comments and suggestions.

The corrections and answers to the reviewer are given as follows:

Emi Govorcin Bajsic and co-workers submitted the manuscript entitled “Preparation and Characterization of Polyethylene biocomposites reinforced by rice husk: application as potential packaging material”, to be published in “Chemistry”. In this paper, author described the uniqueness of LDPE/RH biocomposites as food packaging material. Overall, this is a nice work, thus can be published after addressing the queries.

1. In the introduction, author must provide the importance of rice husk towards the development of bio-degradable polymers. Author also needs to cite the following references; 1. Polymers 2021, 13, 2391 and 2. Polymers 2021, 13, 104.

According to your suggestion we explained the RH importance in introduction part and also we citated the proposed literature as very good bases for our manuscript.

1. For Figures 4, 5 and 6, author must state the number of experiments (n=?) conducted to collect the data with error bars. Also deliver n=? in Figure 7.

For WVP were used three specimens of each sample (now figure 5).

Triplicate of each samples were carried out for water absorption test (now figure 6 and 7).

We performd TGA measurement for LDPE and RH ones.

1. Provide the Table for FTIR stretching frequencies or enhance the explanation.

In investigations for this paper we didn't includ the FTIR measurements, but we made it and in figure below you can see just for example the results for the neat LDPE and LDPE/RH + 30 wt% RH and  LDPE/RH + 50 wt% RH.

Intensity of some peaks increases with increasing RH content.

1. Why only used RH up to 50% wt, what happens above 50% wt?

            Above 50 wt% of RH the films become brittle.

1. Explanation for mechanism must be enhanced for the readers.

We are sorry, which mechanism you think?

In the paper we inserted explanation for the thermal degradation of LDPE (3.5. Thermal Stability of the LDPE/RH biocomposites.Is that OK?

1. Please provide the SEM instrument model as well as the microscopy used in soil-burial test.

In Figure 1 we can nicely see the distribution of RH within the LDPE matrix so we are instead of SEM, used a Olympus model BX50 light microscope ( Olympus Optical Co. Ltd., Japan)

A Olympus model BX50 light microscope ( Olympus Optical Co. Ltd., Japan) with a digital camera Olympus was used for the observation of the neat LDPE and LDPE/RH films with different RH content before and after composting process, Figure 2 and 16.

1. Many sections, the explanation seems to be deficient, it should be rectified in the revision.

According to your suggestion we revised and expand  explanation of results in some sections.

Figures resolution should be enhanced and their captions must be re-written with informative and meaningful.

Corrections made directly in the paper.

 

 

Prof. Emi Govorin Bajsic, PhD

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

No more comments, thank you for the effort done by the authors to improve the manuscript.

Reviewer 2 Report

Author rectified all the issues