scholarly journals Thermal Behaviour and Glass Transition Dynamics of Inclusion Complexes ofα-Cyclodextrin with Poly(D,L-lactic acid)

2008 ◽  
Vol 29 (15) ◽  
pp. 1341-1345 ◽  
Author(s):  
João F. Mano
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Inclusion Complexes ◽  
Thermal Behaviour ◽  
Transition Dynamics

Hyperbranched polyimides crosslinked with ethylene glycol diglycidyl ether: Glass transition dynamics and permeability

Polymer ◽  
2006 ◽  
Vol 47 (19) ◽  
pp. 6765-6772 ◽  
Author(s):  
V.A. Bershtein ◽  
L.M. Egorova ◽  
P.N. Yakushev ◽  
P. Sysel ◽  
R. Hobzova ◽  
...  
Keyword(s):  
Glass Transition ◽  
Ethylene Glycol ◽  
Diglycidyl Ether ◽  
Transition Dynamics ◽  
Hyperbranched Polyimides

Glass transition behavior of carnosine and its impact as a protectant on freeze-dried lactic acid bacteria

2021 ◽  
Author(s):  
Shuto Mikajiri ◽  
Tomochika Sogabe ◽  
Ruodan Cao ◽  
Takahiro Kikawada ◽  
Toru Suzuki ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Lactic Acid Bacteria ◽  
Transition Behavior ◽  
Freeze Dried

Study on the Crystallization Activation Energy of Poly (L-lactic acid) Nucleated with P-tert-butylcalix[8]arene

2018 ◽  
Vol 26 (2) ◽  
pp. 169-175
Author(s):  
Yaoqi Shi ◽  
Liang Wen ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Crystallization Temperature ◽  
Nucleating Agent ◽  
Crystallization Activation Energy ◽  
Temperature Range ◽  
Chain Mobility

The crystallization activation energy (Δ E) of a polymer comprises the nucleation activation energy Δ F and the transport activation energy Δ E*. In this paper, the Δ E of poly (L-lactic acid) (PLLA) nucleated with nucleating agent p- tert-butylcalix[8]arene (tBC8) was calculated. The results showed that the Δ E of nucleated PLLA was 165.97 kJ/mol, which is higher than that of pure PLLA. The reason why Δ E of PLLA increased when incorporating nucleating agent was studied. The increment of glass transition temperature ( Tg) for nucleated PLLA revealed that the polymer chain mobility was restricted by tBC8, which was considered as the reason for the increase of Δ E*. Further, polyethylene glycol (PEG) was added to improve the chain mobility, thus eliminated the variation of the transport activation energy Δ E* caused by tBC8. Then the effect of the increment of crystallization temperature range on the increase of Δ F was also taken into consideration. It was concluded that both decreasing the mobility of chain segments and increasing the crystallization temperature range caused an increase of Δ E for PLLA/tBC8.

Sign in / Sign up

Export Citation Format

Share Document