Abstract
Clay-reinforced polymer composites have been considered as highly demand nanocomposites since several decades. To be utilized as packaging materials, these nanocomposites should possess good impermeability to oxygen and water vapor. The major compatibility issue of the hydrophilic inorganic nanofillers with hydrophobic thermoplastics has been overcome in this work by using the ‘grafting to’ silylation method of two different nanoclays, namely montmorillonite Na+ and halloysite (HNT) nanoclays, at 85 ℃. Organosilanes: 3-aminopropyltriethoxysilane (3-APTES) and vinyltrimethoxysilane (VTMS) were used to functionalize these nanoclays to improve interfacial bonding with linear low-density polyethylene (LLDPE) polymer chains. TGA analysis resulted in higher amount of grafting yield percentages for silane-treated MMT nanoclays (28.9% for MMT-APTES and 24.3% for MMT-VTMS) which are much higher than silane-functionalized HNT nanoclays. The amount of 1, 3 and 5 wt% of each organoclay was melt and mixed with LLDPE to enhance the overall performance properties of the resultant nanocomposites. The maximum tensile strength exhibited by the nanocomposite is around 20.6 MPa for 3 wt% of MMT-APTES concentration. Also, Young modulus improves up to 56% compared to neat LLDPE on the addition of 5 wt% of silane-treated organoclay. The microscopic analysis, especially TEM, provided information about the better dispersion of anisotropic fillers inside the thermoplastic matrix. Moreover, such filler compatibilization also showed 29.4% reduction in oxygen transmission rate (OTR) and 63.5% reduction in water vapor transmission rate (WVTR) value of composite materials with only 5 wt% of nanoclay loading along with improved rheological and ultraviolet (UV) barrier properties of these nanocomposites. The prepared nanocomposites with improved barrier properties could be ideal alternatives for flexible thermoplastic composites as packaging materials. Graphical abstract: Silane functionalization of nanoclays led to uniform distribution of clay in LLDPE matrix which improved mechanical and barrier properties of nanocomposites. [Figure not available: see fulltext.].
| Original language | English |
|---|---|
| Pages (from-to) | 4307-4335 |
| Number of pages | 29 |
| Journal | Polymer Bulletin |
| Volume | 80 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2023 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Funding
Narayan Chandra Das thanks BRNS-DAE, Government of India (35/14/30/2017-BRNS/35307), for funding this research work. Dr. Das also thanks the Central Research Facility (CRF), IIT Kharagpur. Narayan Chandra Das thanks BRNS-DAE, Government of India (35/14/30/2017-BRNS/35307), for funding this research work. Dr. Das also thanks the Central Research Facility (CRF), IIT Kharagpur.
| Funders | Funder number |
|---|---|
| Central research facility | |
| Board of Research in Nuclear Sciences | 35/14/30/2017-BRNS/35307 |
| Indian Institute of Technology Kharagpur |
Keywords
- Barrier properties
- LLDPE nanocomposite
- Mechanical properties
- Nanoclays
- Packaging
- Silylation