The influence of additives on polymer matrix mobility and the glass transition

Abstract

In the region near an interface, the microscopic properties of a glass forming liquid may be perturbed from their equilibrium bulk values. In this work, we probe how the interfacial...

Color Stability, Chemico-Physical and Optical Features of the Most Common PETG and PU Based Orthodontic Aligners for Clear Aligner Therapy

“…Moreover, all the aligners present a T g value in the typical range observed in PETG polymers [23], corresponding to 80 • C, 83 • C, and 88 • C for GA, EK, and EP, respectively. The ZN and IL samples show higher T g values, corresponding to about 97 • C and 111 • C, respectively, not typical of pure PU, but probably ascribed to the additives present in the PU-based mixtures, as also diffusely found in the literature [27,28]. The UV-visible absorbance curves of the clear aligners are shown in Figure 4.…”

“…The chemico-physical analyses (XRD, FTIR and DSC) reveal that some of the as received aligners (EP, EK, GA) are composed of PETG-based thermoplastic materials [ 17 , 23 , 25 ], while ZN shows a different polymer base, attributable to polyurethane (PU) [ 26 , 27 , 28 ]. However, all the aligners are characterized by very low crystalline order, as underlined by measuring the full width at half maximum (FWHM) of each XRD diffraction peak.…”

Tailoring the separation performance of ZIF-based mixed matrix membranes by MOF-matrix interfacial compatibilization

“…The incorporation of additives (e.g. ZIFs) in polymer materials can affect the T 8 of the composite material in three manners: (1) strong interaction between the additive and the matrix decreases the interfacial polymer mobility (rigidification/physical crosslinking), enhancing the T 8 , (2) weak interaction between the additive and the matrix distorts the interfacial polymer mobility (derigidification), suppressing the T 8 , or (3) the additive does not influence the polymer bulk arrangement, leaving the T 8 unchanged (60,61]. The addition of the ZIFs to Matrimid (O wt% PBI) affects the MMM T 8 in two manners (Table 3).…”

Plasticizing effect of biodegradable dipropylene glycol bibenzoate and epoxidized linseed oil on diglycidyl ether of bisphenol A based epoxy resin

“…The increase in storage modulus can be attributed primarily to cross link density which was improved for 10% loading due to good interaction between DPGDB molecules and epoxy chains which may be possible due to homogeneous network formed through primary and secondary amine cross linkage between that of alkyl polyamine and the weight fraction mixture cycloaliphatic amine and DPGDB (Table 3). 45–51 Even loss modulus of 10 wt% modified samples was improved from 234.13 MPa for neat to 262.78 MPa which is an increase of about 12%. Increase in loss modulus indicates that there is some internal damping or energy dissipation effect within the system due to presence of plasticizer.…”

“…Even from TMA analysis it seems that there is an optimum interaction between plasticizer and epoxy system for 10% EP9009 loading (Table 4). It has been reported in literature that with favorable optimum interaction, there will be increase in transition temperatures (Tg) and decrease in expansion coefficients 45–51 …”