Role of lubricant with a plasticizer to change the glass transition temperature as a result improving the mechanical properties of poly(lactic acid) PLLA

Abstract

Poly (lactic acid) (PLLA) is the best important bioplastics derived from renewable resources like blackstrap molasses (sugar beet, date palm and sugar cane). PLLA is brittle and has a low elongation at break, which hinders its applications in the industry. One method to solve this problem is to improve its mechanical properties by adding plasticizers. The PLLA blends were prepared at first by solution blending as a solvent casting method and then melting using a hydraulic hot press. PLLA was blended with a plasticizer (GMS/ TA) to obtain a higher ductile of PLLA. The addition of lubricant and plasticizer (GMS/TA) leads to reduce the glass transition temperature (T g ), melting point (T m ), and the cold crystallization temperature (T cc ) in PLLA blends. The mechanical properties of PLLA have been investigated. The results indicated compatibility between PLLA and additives. The elongation at the break of the PLLA blend is stretched 270% with a tensile strength of 16 MPa. The addition of lubricant with the plasticizer leads to sliding the chain of PLLA, which causes to increase the strain. The physical blending has been demonstrated to be an effective technique to obtain an environmentally friendly PLLA blend with good mechanical properties, therefore it can be used in the food packaging sector.

Biodegradable Molybdenum/Polybutylene Adipate Terephthalate Conductive Paste for Flexible and Stretchable Transient Electronics

“…The reduced friction between Mo-Mo microparticles, Mo microparticles-PBAT polymers, and PBAT-PBAT polymers due to the added TG improved the mobility of PBAT chains, thus enhancing the elongation. [52,53] The tensile strengths decreased also due to the improved PBAT chains mobility resulting in deformations in the Mo/PBAT pastes at lower tensile forces. It should be noted that a TG 6.5 vol% factor effectively enhanced elongation by almost 1.86 times.…”

Effects of Erucamide on Fiber “Softness”: Linking Single-Fiber Crystal Structure and Mechanical Properties

“…Unlike stress-induced crystallization and orientation of crystallites in fiber melt spinning, in the case of polymer films, the absence of the external stress facilitates spherulitic morphology with radial symmetry. , The fact that erucamide had little effect on the size of the daughter lamellae composed of laterally oriented chains, while having a significant effect on the size of the parent lamellae composed of chains oriented along the fiber axis (i.e., along the stress direction during melt spinning), provides evidence for the mechanism underpinning the erucamide action, i.e., it is associated with the stress-induced crystallization. We also note that, whilst plasticizer addition has been reported to improve ductility of polymer films, it reduced the film melting point, in contrast to the effect of erucamide on the PP fibre observed here …”

Design and Study of Novel Composites Based on EPDM Rubber Containing Bismuth (III) Oxide and Graphene Nanoplatelets for Gamma Radiation Shielding

“…The graphene compounds have a residual mass of 6.55% and 7.74% corresponding to EPDM/GN and EPDM/GN/P, respectively. It is important to note that the glass transition temperature does not vary significantly with the content of the filler or the presence of the PEG additive [ 44 , 45 ].…”

“…Glass transition temperature (Tg) depicted in Table 5 , obtained from DSC, did not change, a fact that indicates that PEG did not show a plasticizer effect [ 44 ], and according to the results presented above, it is more likely to have an effect on the crosslinking process. However, it is important to mention that the thermograms of the compounds containing PEG exhibited an endothermic process associated with the melting of PEG, which suggests segregation of this additive (see Supplementary Materials ).…”