Introduction

Concerns about the environment and the need for a shift away from plastics derived from fossil fuels have led to a rise in the demand for sustainable and eco-friendly packaging materials in recent years. Further, plastics are mostly made from fossil fuels and end up in the environment as solid waste over time, which causes more disruption to the planet. In accordance with this, renewable resource-based biocomposites present a possible answer to these problems [1]. The creation of food packaging materials that are both biodegradable and efficient in maintaining food quality is one area of concentration. Moreover, numerous bio-based polymers are available which can effectively produce features similar to the non-biodegradable polymers. One such thermoplastic polymer that is both biodegradable and bio-based polyester is the polylactic acid (PLA) which can be produced from plant-based ingredients such as sugarcane, maize starch, and other renewable resources which are available in the markets [2]. Because it is biodegradable in industrial settings, it has attracted a lot of interest because of its environmentally beneficial qualities. PLA is suited for use in packaging, textiles, and biomedical devices due of its exceptional mechanical qualities, which include high tensile strength and stiffness [3].

PLA has advantages for the environment, but its brittleness, low heat stability, and restricted flexibility can limit its use in applications that call for more flexible and durable materials. PLA is frequently combined with additional polymers or plasticizers to improve its performance qualities for particular applications, including food packaging, in order to get around these shortcomings. In order to resolve the issue of flexibility and durability of the PLA polymers, biodegradable, and semi-crystalline polyester, polycaprolactone (PCL) is blended along with the PLA matrix. Because, PCL is renowned for its exceptional biodegradability, low melting point (around 60 °C), and flexibility [4]. PCL is a useful material for decreasing plastic waste because, unlike certain bioplastics, it degrades in a range of environmental conditions, including compost and marine settings. Although it is created from petroleum-based materials, research on sustainable material development has turned its attention to it because of its exceptional biodegradability. To increase its performance for packaging and other industrial applications, PCL is frequently blended with stronger materials because its mechanical strength and stiffness are comparatively low [5].

Owing to the features, both PLA/PCL matrix is widely utilized as a film material in food packaging industries due to their sustainability. Thus, the characteristics are analyzed by various research scholars. For example, Lukic et al. [6] analyzed the PVA/PCL films with thymol and carvacrol for food packaging applications and resulted that the films are antioxidant and has good stability and physical properties and also low water absorption. Similarly, Ramos et al. [7] investigated different polymers such as PBS, PHB, and PLA films with PCL for flexible food packaging application. According to the results of the study, the polymer blend with 20% PCL increased tensile elongation by 26.3%, 68%, and 171%, water vapor barrier by 28.3%, 26.8%, and 30.3%, respectively. Thus, it is evident that the blends of PLA/PCL matrix are a great approach for the food packaging applications.

However, immiscibility between the PLA and PCL matrix arises because PLA and PCL have different solubility parameters (21.9 MPa1/2 and 19.2 MPa1/2, respectively). To resolve this kind of issue, a biocompatibilizer is added to the matrix because it strengthens the interfacial adhesion and compatibility between the polymer mix which leads to the increase in thermal, mechanical, and degrading properties [8]. One promising biocompatibilizer is the lignin which is extracted from the grape stalk since it consists of approximately 20% lignin content within it. Further, lignin improves the hydrophobic and hydrophilic polymers’ interface adhesion, and its aromatic structure enhances polymer blends’ mechanical strength, thermal stability, and UV resistance [9]. Thus, due to the excellent features, lignin is extracted from various biomasses by numerous research scholars. For instance, Mariana et al. [10] analyzed lignin reinforced with biopolymeric blends. The author resulted that the lignin with PLA improves the mechanical properties and the water barrier of the material, respectively.

Similarly, Roostazadeh et al. [11] extracted lignin from wheat straw and reinforced with starch composite films and resulted that 20% of lignin improved mechanical properties such as tensile strength and modulus of 4.8 and 0.9–8 and 2.4 MPa. This rise can be largely attributed to the film’s enhanced crystallinity, which climbed from 29% to 48.3%. Likewise, Chihaoui et al. [12] extracted lignin containing cellulosic fibrils from date palm and reinforced with plasticized PLA biocomposite and resulted that with 8% of lignocellulosic fibrils improves tensile strength, Young’s modulus up to 250% and 1100%, and toughness of about 16 MJ/m3, respectively. Thereby, it is evident that lignin improves mechanical properties and works as a excellent biocompatibilizer. Additionally, essential oils are added to the composite because essential oils have the antibacterial and antioxidant qualities which contribute to the preservation and extension of food shelf life in food packaging application. In addition, they have the natural plasticizing effect of strengthening the film’s barrier against moisture and oxygen while simultaneously increasing its flexibility [13].

Thus, to achieve these features, an essential oil is added which is extracted from orange (Citrus reticulata) peel due to its potent antibacterial and antioxidant qualities, orange peel essential oil is useful in halting the growth of microorganisms and averting oxidation in food products. Additionally, it has limonene, a naturally occurring plasticizer that increases flexibility of films [14]. Thus, plentiful research scholars used essential oil in the composite material for food packaging applications. Typically, Chen et al. [15] developed packaging film with chitosan and oregano oil reinforced with cellulose nanofibril and resulted that the addition of oregano oil and chitosan improved the antimicrobial properties and mechanical properties such as tensile strength of 16.80 MPa. Similarly, Liu et al. [16] utilized cinnamon oil and curcumin reinforced films for meat preservation and freshness indicator. From the results of the study, the cinnamon oil films reduced the water absorption by 336.27% and increased tensile strength by 1.4 MPa thus, serving a excellent biomass film for packaging. Likewise, Arun et al. [17] developed a nanocomposite as a replacement for synthetic plastics in food packaging industry. The author incorporated cellulose nanofibrils with PVA matrix, lemon oil, and linseed oil and resulted that the composite film shows free radicle scavenging activity was 31.52 ± 0.08%, biodegradability; 87.34 ± 0.91%, and contact angle of 91.3° ± 0.79° with the addition of oils. Thereby, it is concluded that the essential oils increase the antimicrobial activities of the composite films making them suitable for food packaging [18, 19].

To sum up, this study offers a novel strategy for biocomposite food packaging via the production of a film that combines PLA/PCL blends with orange peel bio-plasticizer and lignin as a biocompatibilizer. The innovation is in using orange peel extract to improve the film’s antimicrobial, antioxidant, and flexible qualities, while lignin maximizes polymer compatibility and mechanical performance. This research not only fulfills the demand for sustainable packaging solutions but also creatively repurposes agricultural byproducts, providing a compelling advancement in the creation of environmentally friendly and functional packaging materials.

Materials and methods

Materials

The biodegradable PCL and PLA granules are used as polymer in this research study, PCL (polycaprolactone) is a biodegradable polyester with a very low melting point of 60 °C (140 °F) and specific gravities of 1.14 g/cm3while PLA (polylactic acid) is a renewable plastic made from food starches with a melting point of ~ 175 °C and specific gravities of 1.24 g/cm3. Both PLA and PCL sourced from Metalon Marketing in Delhi, India. Sigma-Aldrich, USA, provided the liquidized chloroform with a high degree of purity. Metro Composite in Chennai, India, is the source of the lignin recovered from grape stalks. Following the steam distillation process in a laboratory, OEO was purified and given a density of 0.845 g/cm3.

Orange peel essential oil preparation

The process of steam distillation was used to extract the orange peel essential oil (OEO), as Fig. 1 clearly illustrates. This method involved peeling the orange peel from the cleaned fruit and distilling it. After letting the peel dry, it was roughly crushed. A 200 ml of water and 100 g of ground peel were added to the distillation flask. The oil produced constituent’s limonene like compounds which are having antimicrobial and anticancer properties, and which is much below its usual boiling point, caused by the heating of the distillation machine. A separating funnel was used to separate the two distillate layers, one thick and the other less densein order to collect the OEO, which was then kept in a glass bottle. The presence of natural ingredients and sustainable characteristics of the naturally prepared OEO is preferred in food packaging industry over commercially extracted essential oil. The steam distillation process is followed with accordance to the reference [20].

Fig. 1
figure 1

Orange peel essential oil extraction process

Full size image

Biocomposite film preparation

In order to produce a clear film-forming solution, the various PLA concentrations in chloroform were combined with 10% PCL polymer using 1% lignin biocompatibilizer in a beaker. The mixture was then placed on a hot plate with a magnetic stirrer, the temperature of which was set to 50 °C, and the stirrer speed was continuously maintained at 500 rpm for about 60 min. The grape stalk is used to extract the lignin biocompatibilizer [21]. The aforementioned transparent solution was then mixed with varying weight percentages of OEO (Table 1), and stirring was done constantly until a homogeneous solution was obtained. After that, the solution was subjected to a 15-min sonication process to improve the blending of the polymer molecules. Following the formation of the films and a 24-h cure period at room temperature, the resulting solution was transferred to a glass petri dish [22]. After that, the dried film was manually removed from the petri dish, as shown in Fig. 2. Table 1 contains a list of the bio-based films along with their various ratios.

Table 1 Composition of biocomposite films
Full size table
Fig. 2
figure 2

Diagrammatic representation of orange peel essential oil using PLA and PCL blended film

Full size image

Characterizations

Surface color and opacity of film

A spectrophotometer (X Rite528) was used to measure the color of the composite film surface. The ASTM D 2244 color measurement procedure was appropriately followed.

FTIR analysis

The Perkin Elmer spectrophotometer RX1 in ATR mode was utilized to perform Fourier transform infrared spectroscopy (FTIR) on the different functional groups of PLA/PCL in combination with OEO bio-based films. From the small film sample, a rectangle measuring 22 cm was cut out and put into the sample container. After letting the infrared beam travel through the specimens of each individual sample, the reference spectral values were obtained.

TGA analysis

The TGA apparatus (TGA Q500, TA Instrument, INC.) was used to measure the thermal stability of films test samples are heated at a rate of 10 °C/min in a nitrogen medium up to 600 °C.

Barrier properties

The water vapor permeability of the PLA/PCL blended films is determined using Lyssy L80-5000. This test is conducted in a room with a 90% relative humidity level at 25 °C. The ASTM F1249-90 was utilized to test for water vapor permeability.

Hydrophobicity Behaviour

The water absorption was examined using a HOLMARK goniometer. Water droplets were applied to three different sites on the film at room temperature  and the angle between datum and bubble surface is measured.

Mechanical properties of films

The film sample’s mechanical performance was evaluated using a universal testing device (Tinius 50 Olsen H10KS UK). A constant dimension of 150 mm × 25 mm and a speed range of 50 mm/min were maintained in accordance with ASTM D882.

Scanning Electron Microscope

The PLA/PCL/OEO composite films were subjected to morphological and structural analysis utilizing a 5.0 kV-powered SEM (S-4800, Hitachi, Japan). To prevent the film samples from charging, they are coated with gold prior to scanning.

Antimicrobial Behaviour 

The PLA/PCL/OEO composite films’ antimicrobial resistance against gram-positive and gram-negative bacteria, including S. aureus and E. coli, was evaluated using the zone of inhibition method (ISO 22196). The samples were put it in a bacterial suspension for 48 h at 37 °C.

Results and discussion

Opacity

The opacity test results for the PLA/PCL/OEO film samples demonstrate a clear trend in opacity percentages as the composition of the films varies. The samples, labeled M1–M5, show an increase in opacity as the amount of orange essential oil (OEO) in the film composition rises, while the polycaprolactone (PCL) content remains constant at 10 wt.%. Sample M1, which consists of 100% PLA without any PCL or OEO, exhibits the lowest opacity at 18.9%. As OEO is introduced, and its content increases from 0 to 15% in subsequent samples (M2–M5), the opacity correspondingly rises from 21.6% in M2 to 28.7% in M5. This increase in opacity is attributed to the introduction and rising concentration of OEO, which causes greater light scattering within the film matrix due to the formation of OEO droplets or domains within the PLA/PCL blend [23]. Additionally, the heterogeneous nature introduced by the OEO might enhance the refractive index mismatch within the polymer matrix, thereby increasing the opacity. These results suggest that the presence and concentration of OEO play a significant role in influencing the optical properties of PLA/PCL films, which is critical in applications where transparency or light diffusion is a desired attribute. The film is suggested as the best packaging material for light-sensitive packaged food goods in light of the aforementioned observations [24]. Figure 3 represents opacity behavior of various film samples.

Fig. 3
figure 3

Opacity behavior of various film samples

Full size image

Thermogravimetry analysis

The thermogravimetric analysis (TGA) results for the PLA/PCL/OEO film samples reveal the thermal stability of the films and their decomposition behavior as a function of temperature and its graphical representation for all the prepared samples are presented in Fig. 4. TGA measures the weight loss of a material as it is heated, providing insights into its thermal degradation properties. The two key parameters from the TGA data presented are the percentage of weight loss (TG%) at the onset of significant decomposition and the corresponding decomposition temperature at which this weight loss occurs. For the film samples labeled M1–M5, there is an observable trend of increasing thermal stability with the addition of orange essential oil (OEO). Sample M1, composed of 100% PLA without any PCL or OEO, has the lowest decomposition temperature at 261 °C with a TG% of 81%. PLA materials show a lower molecular weight and rapid thermal breakdown as a result of the molecular chain with carboxyl terminations breaking first at higher temperatures [25].

Fig. 4
figure 4

TGA of PVA/PCL and essential oil reinforced film samples

Full size image

As OEO is added to the subsequent samples, there is a noticeable increase in both the decomposition temperature and the TG%. For example, sample M2, which contains 10 wt.% PCL and 0 wt.% OEO, shows an increase in the decomposition temperature to 275 °C and a slight increase in TG% to 83%. PCL, which displays exceptional thermal stability at high temperatures compared to other PLA, is the cause of this increase in thermal stability [26]. As the OEO content increases from 5 wt.% in M3 to 15 wt.% in M5, the decomposition temperatures rise progressively from 283 °C in M3 to 305 °C in M5, and the TG% also increases from 89 to 91%. As a result, there is a minor decrease in thermal stability [27]. The improvement in thermal stability with higher OEO content suggests that OEO contributes to enhancing the thermal resistance of the PLA/PCL films. This could be due to the potential interactions between OEO and the polymer matrix, which may result in a more thermally stable network structure, reducing the rate of thermal degradation. Moreover, OEO might act as a barrier that limits the release of volatile degradation products, thereby delaying the onset of decomposition. The results from this TGA analysis indicate that incorporating OEO into the PLA/PCL blend improves the thermal stability of the films, making them more suitable for applications that require enhanced thermal resistance.

FTIR analysis

Figure 5 displays the five, ten, and fifteen percent OEO FTIR spectra of films. The existence of the CH3 group and the (C = O) stretching of the carbonyl group in PLA are indicated by the absorption peaks at 1450 cm-1 and 1760 cm-1, respectively. The film’s asymmetric and symmetric –CH stretching is indicated by the peaks that emerged at 1360 cm-1 and 1380 cm-1, respectively. The stretching vibration of the C–O–C–C bonds in the essential oil is also attributed to a peak at 1100 cm-1. The carbonyl group of PCL is indicated by a peak at 1727 cm-1, and the backbone C–C and C–O stretching modes of PCL are defined by the characteristic peak at 1294 cm-1. Because PCL was added to the PLA matrix, the band intensities at 1170 cm-1 and 1727 cm-1 were clearly reduced. The –CH stretching bands are represented by the peaks seen between 2860 cm-1 and 3000 cm-1. The peaks indicating high PLA absorption in this location become less intense with increasing OEO concentration. One possible explanation for the decline in the area could be the limonene level found in the OEO [27].

Fig. 5
figure 5

FTIR spectra of prepared film samples

Full size image

Barrier properties of Biofilm

The water vapor transmission rate (WVTR) test results for the PLA/PCL/OEO film samples show a decreasing trend in WVTR values as the concentration of orange essential oil (OEO) increases. WVTR measures the rate at which water vapor passes through a material, indicating its effectiveness as a barrier against moisture. The film samples, designated as M1–M5, demonstrate that as the OEO content increases, the WVTR values decrease, suggesting an improvement in the water vapor barrier properties of the films [28]. Sample M1, consisting of 100% PLA without any PCL or OEO, has the highest WVTR of 180 g/m2/day, indicating the least effective barrier against water vapor. When 10 wt.% of PCL is introduced in M2, and as the OEO content increases incrementally from 0% in M2 to 15% in M5, the WVTR values decrease progressively from 140 g/m2/day in M2 to 110 g/m2/day in M5. This reduction in WVTR with increasing OEO content could be due to the hydrophobic nature of OEO, which enhances the water resistance of the polymer matrix by reducing the free volume and forming a more compact structure that is less permeable to water molecules [29]. Additionally, the OEO interacts with the PLA/PCL blend to create a more tortuous path for water vapor diffusion, further reducing its transmission rate. These results imply that the incorporation of OEO not only modifies the optical properties of the films but also significantly improves their barrier performance, making them suitable for applications requiring moisture resistance [30]. Figure 6 denotes graphical representation of barrier proper of PVA/PCL samples.

Fig. 6
figure 6

Barrier proper of PVA/PCL samples

Full size image

Hydrophobicity behavior of Biofilm

Figure 7 shows hydrophobicity of PVA/PCL samples. The contact angle measurements for the PLA/PCL/OEO film samples illustrate an increasing trend in hydrophobicity with the addition of orange essential oil (OEO). The contact angle test assesses the wettability of a surface, where a higher contact angle indicates a more hydrophobic (water-repellent) surface. The film samples, labeled M1 through M5, show a progressive increase in contact angle from 66° in M1 to 79° in M5 as the OEO content is increased, while the PCL content remains constant at 10 wt.%. Sample M1, which is composed entirely of PLA (100 wt.%) without any PCL or OEO, exhibits the lowest contact angle of 66°, indicating a relatively hydrophilic surface. As OEO is introduced in subsequent samples (M2–M5) and its concentration rises from 0 to 15%, the contact angle increases from 71° in M2 to 79° in M5. Conversely, the presence of terpenes in the oil improved the hydrophobicity of the films when the weight % of OEO rose [31]. This increase in contact angle can be attributed to the hydrophobic nature of OEO, which, when incorporated into the PLA/PCL matrix, enhances the surface hydrophobicity of the films. The incorporation of OEO likely reduces the surface energy by forming a more non-polar surface, thereby resisting water spreading and leading to higher contact angles. Furthermore, the consistent increase in contact angle with rising OEO content suggests that OEO effectively modifies the surface characteristics of the PLA/PCL blend, making the surface less wettable [32]. This enhanced hydrophobicity may be beneficial for applications where water resistance is desired, such as in packaging materials or coatings. These results reinforce the idea that the addition of hydrophobic agents like OEO significantly alters both the physical and chemical properties of biopolymer-based films.

Fig. 7
figure 7

Hydrophobicity of PVA/PCL samples

Full size image

Mechanical properties of Biofilm

The mechanical properties of the PLA/PCL/OEO film samples, including tensile strength, elongation at break, and Young’s modulus, exhibit notable changes as the composition of orange essential oil (OEO) increases. The tensile strength, which measures the maximum stress a material withstands while being stretched or pulled before breaking, shows a decreasing trend with higher OEO content. Sample M1, consisting of 100% PLA, has the highest tensile strength at 51.38 MPa. The best tensile strength and smallest elongation at break were found in pure PLA film, which is glassy by nature and restricts its use in deforming applications [33, 34]. As OEO is added in subsequent samples (M2–M5) while maintaining a constant PCL content of 10 wt.%, the tensile strength decreases progressively from 47.31 MPa in M2 to 28.63 MPa in M5. This decline in tensile strength could be due to the plasticizing effect of OEO, which reduces the intermolecular forces within the polymer matrix, making it more flexible but less strong. Conversely, the elongation at break, which indicates the ductility of the material, increases significantly with the addition of OEO. M1 has the lowest elongation at break at 6.64%, indicating a brittle nature. With increasing OEO content from M2 to M5, the elongation at break rises dramatically, reaching 43.21% in M5. This increase suggests that the presence of OEO imparts greater flexibility and extensibility to the films, which could be attributed to the disruption of PLA’s crystalline structure and the enhanced plasticity from OEO, allowing the polymer chains to move more freely under stress. Young’s modulus, which reflects the stiffness of the material, also shows a decreasing trend with the addition of OEO. M1 has the highest Young’s modulus at 1.085 GPa, signifying a stiffer material. As the concentration of OEO increases, Young’s modulus decreases slightly from 1.066 GPa in M2 to 0.97 GPa in M5. This reduction in stiffness is consistent with the plasticizing effect of OEO, which makes the film samples less rigid and more flexible. Figure 8 shows mechanical testing of samples a) Young’s modulus (GPa) and b) tensile strength (MPa) and elongation at break (%).

Fig. 8
figure 8

Mechanical testing of samples a Young’s modulus (GPa) and b tensile strength (MPa) and elongation at break (%)

Full size image

Microstructure of fractured Biofilm

The scanning electron microscopy (SEM) analysis of the PLA/PCL/OEO film samples provides detailed insights into the morphological changes in the polymer matrix upon the addition of PCL and OEO. The micrographs, labeled as Fig. 9a–d, highlight the surface characteristics and the degree of compatibility among the different components. Figure 8a shows the SEM image of a plain PLA sample without the addition of PCL or OEO. The surface is relatively smooth and homogeneous, which is characteristic of pure PLA. The absence of additional components such as PCL or OEO results in a uniform structure with no visible voids or phase separations, confirming the film’s purity and homogeneity. Figure 9b presents the SEM image of sample M2, which contains PLA blended with 10 wt.% PCL but without OEO. The micrograph reveals the presence of voids (highlighted with yellow squares), indicating some degree of incompatibility or poor dispersion between PLA and PCL. These voids likely arise from phase separation during the blending process, leading to microstructural defects within the film. Figure 8c depicts the SEM image of a sample with fine mixing of PLA and PCL, showing improved interfacial compatibility compared to the sample in Fig. 9b. The surface displays a more uniform distribution of PCL within the PLA matrix, although small imperfections are still visible. This finer mixing suggests that appropriate blending techniques can enhance the miscibility of PLA and PCL, reducing phase separation and minimizing the occurrence of voids or defects. Figure 9d shows the SEM image of a sample with fine mixing of PLA, PCL, and OEO. The surface morphology is further refined compared to the previous samples, with fewer visible voids and a more homogeneous structure. The addition of OEO appears to aid in better dispersion of PCL within the PLA matrix, creating a more integrated and compatible polymer network [35]. The smoother and more uniform surface indicates that OEO acts as a plasticizing agent, improving the overall miscibility and reducing microstructural flaws in the composite films. Figure 9 shows SEM analysis of samples a) M1, b) M2, c) M3, and d) M5.

Fig. 9
figure 9

SEM analysis of samples a M1, b M2, c M3, and d M5

Full size image

Antimicrobial properties

Table 2 presents the antimicrobial inhibition growth of film samples for various bacteria. The antimicrobial test results for the PLA/PCL/OEO film samples demonstrate that the effectiveness of the films against two common bacterial strains: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The antimicrobial activity is measured by the inhibition zone diameter (in millimeters) around the film samples, where a larger inhibition zone indicates stronger antibacterial activity.

Table 2 Inhibition range of Biofilm samples
Full size table

The results show a clear trend of increasing antimicrobial activity with higher OEO content. The samples M1 and M2 give almost similar inhibition range against S. aureus and E. coli. This is because of both PLA and PCL have similar antimicrobial resistance. However, sample M3, which contains 5 wt.% OEO, exhibits inhibition zone diameters of 13.6 mm against S. aureus and 14.5 mm against E. coli. As the OEO concentration increases to 10 wt.% in M4, the inhibition zones increase to 15.7 mm for S. aureus and 16.6 mm for E. coli. The highest antimicrobial activity is observed in sample M5, which has 15 wt.% OEO, showing inhibition zones of 20.5 mm against S. aureus and 19.7 mm against E. coli. On the other hand, the inhibition zones were 14.5, 16.6, and 19.7 mm, respectively, when OEO was tested against the gram-negative bacteria E. coli [36, 37]. These findings unequivocally show the potent antibacterial action of the d-limonene (94.00%) and beta-mycrene (1.18%) components of OEO, which subsequently suppress the growth of harmful microorganisms in food items. As a result, it was shown that adding OEO helped to stop bacterial development in the biocomposite films that were made [38, 39]. The enhanced antimicrobial activity with increasing OEO content is attributed to the inherent antibacterial properties of orange essential oil, which contains bioactive compounds such as limonene, linalool, and terpenes. These compounds can disrupt the bacterial cell membrane, inhibit bacterial growth, and lead to cell death. The increasing concentration of OEO in the film samples likely results in a higher release of these antimicrobial agents, leading to more effective inhibition of bacterial growth.

Conclusions

In conclusion, the comprehensive analysis of the PLA/PCL/OEO film samples across various tests indicates that the specimen M5, with 15 wt.% OEO, exhibits superior properties in all evaluated aspects. M5 demonstrated the highest opacity of 28.7%, making it an ideal candidate for light-sensitive packaging applications due to enhanced light diffusion and reduced transparency. Thermogravimetric analysis (TGA) showed that M5 has the highest decomposition temperature of 305 °C and a TG% of 91%, suggesting improved thermal stability resulting from the reinforcing effect of OEO, which potentially forms a more thermally stable network within the polymer matrix. The water vapor transmission rate (WVTR) for M5 was the lowest at 110 g/m2/day, indicating excellent moisture barrier properties attributed to the hydrophobic nature of OEO, which reduces water vapor permeability by creating a more compact and tortuous path for diffusion. Furthermore, M5 had the highest contact angle of 79°, highlighting its enhanced hydrophobicity, which is beneficial for applications requiring water-resistant surfaces. In terms of mechanical properties, M5 displayed the highest elongation at break of 43.21% and a moderate Young’s modulus of 0.97 GPa, signifying an optimal balance between flexibility and stiffness, making it suitable for various flexible packaging applications. The SEM analysis of the samples further supports these findings, showing that M5 has a more homogeneous structure with fewer visible voids compared to the other samples. The fine dispersion of OEO in the PLA/PCL matrix in M5 contributes to a more integrated and compatible polymer network, minimizing phase separation and microstructural flaws. This enhanced morphology not only improves the mechanical and thermal properties but also provides a better barrier against moisture and microbial penetration. Moreover, the antimicrobial test results for M5 showed the largest inhibition zones of 20.5 mm against Staphylococcus aureus and 19.7 mm against Escherichia coli, confirming its superior antimicrobial efficacy due to the higher release of bioactive compounds like limonene from OEO. Overall, the combination of improved thermal stability, mechanical flexibility, hydrophobicity, and antimicrobial properties makes M5 the most promising candidate for potential applications in packaging and other related fields.