Biodegradable Poly(ester-urethane)s Containing Poly(butylene succinate) and Mesogen Segments

2013 ◽  
Vol 807-809 ◽  
pp. 567-570
Author(s):  
Xian Qun Luo ◽  
Chun Di Zhang ◽  
Jing Cao ◽  
Xin Guang Wang ◽  
Xian Ying Cao ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Enzymatic Degradation ◽  
Degradation Rate ◽  
Hexamethylene Diisocyanate ◽  
Solution Polymerization ◽  
Butylene Succinate ◽  
Relative Crystallinity ◽  
Phase Transition Temperatures ◽  
Biodegradable Poly

A series of biodegradable segmented poly (ester-urethane) s were prepared by solution polymerization of poly (butylene succinate) (PBS), mesogenic diol (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and enzymatic degradation were examined respectively. It was found that introducing mesogen segments could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures, the degree of relative crystallinity (Xc) and the enzymatic degradation rate.

Synthesis and Properties of Biodegradable Liquid Crystalline Poly(ester-Urethane)s Based on Poly(L-Lactic Acid)

2013 ◽  
Vol 652-654 ◽  
pp. 459-462
Author(s):  
Ya Tong Guo ◽  
Zhu Zheng ◽  
Zhen Qi Hou ◽  
Jie Du
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Physical Properties ◽  
Liquid Crystalline ◽  
Degradation Rate ◽  
Hydrolytic Degradation ◽  
Hexamethylene Diisocyanate ◽  
Solution Polymerization ◽  
Phase Transition Temperatures

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(L-lactic acid) (PLLA), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and hydrolytic degradation were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate.

Synthesis and Characterization of Biodegradable Segmented Liquid Crystalline Poly(Ester-Urethane)s

2011 ◽  
Vol 287-290 ◽  
pp. 2106-2109 ◽  
Author(s):  
Jie Du ◽  
Xian Ying Cao
Keyword(s):  
Liquid Crystalline ◽  
Degradation Rate ◽  
Hydrolytic Degradation ◽  
Hexamethylene Diisocyanate ◽  
Synthesis And Characterization ◽  
Solution Polymerization ◽  
Texture Characteristic ◽  
Butylene Succinate ◽  
Phase Transition Temperatures

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(butylene succinate) (PBS), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, hydrolytic degradation and morphological textures were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate. The mesogenic monomer and mesogenic diol could exhibit a schlieren texture characteristic of nematics, and some of the poly(ester-urethane)s could display a grainy texture.

Biodegradability of Poly (butylene succinate) under Enzymatic Degradation

2013 ◽  
Vol 750-752 ◽  
pp. 1318-1321 ◽  
Author(s):  
Bing Xin Sun ◽  
Cheng Zhi Chuai ◽  
Si Luo ◽  
Ying Guo ◽  
Xu Qiao Feng
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Enzymatic Degradation ◽  
Growth Process ◽  
Linear Growth ◽  
Butylene Succinate ◽  
Surface Corrosion ◽  
Acclimation Period

To investigate the biodegradability of PBS, films made of PBS were subjected to enzymatic degradation. The declining thermal stability and XRD diagrams showed that the crystallinity of PBS was reduced after degradation. SEM results confirmed that the mode of enzymatic degradation was surface corrosion. In addition, the weight loss of the material did not experience the so-called acclimation period, but showed a typical linear growth process.

Novel Poly (butylenes succinate-block-1,3-propylene sebacate): Synthesis and Enzymatic Degradation

2013 ◽  
Vol 774-776 ◽  
pp. 569-572
Author(s):  
Zong Hua Kang ◽  
Chang Lu Wang
Keyword(s):  
Thermal Properties ◽  
Enzymatic Hydrolysis ◽  
Enzymatic Degradation ◽  
Biodegradable Materials ◽  
Pseudomonas Cepacia ◽  
Butylene Succinate ◽  
Molar Ratios ◽  
H Nmr ◽  
Biodegradable Poly

This study synthesizes a series of aliphatic biodegradable poly (butylene succinate-block-1,3-propylene sebacate) (PBS-b-PPS) copolyesters by incorporation of PPS into the PBS molecular chains at various molar ratios. The effects of these compositions on the thermal properties, crystallinity and biodegradability were investigated.The PBS-b-PPS were characterized using 1H NMR, DSC and POM.Biodegradability was evaluated by enzymatic hydrolysis with a lipase from Pseudomonas cepacia. The copolyesters might be potentially useful as the biodegradable materials.

scholarly journals Synthesis and photocatalytic properties of Sn–TiO2 nanomaterials

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060018
Author(s):  
E. M. Bayan ◽  
T. G. Lupeiko ◽  
L. E. Pustovaya ◽  
M. G. Volkova
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Sol Gel ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Light Activation ◽  
X Ray ◽  
Tio2 Nanomaterials ◽  
Visible Light Activation ◽  
Thermal Stability Of

Sn-doped TiO2 nanomaterials were synthesized by sol–gel method. It was shown the phase compositions and phase transitions change with the introduction of different tin amounts (0.5–20[Formula: see text]mol.%). X-ray powder diffraction was used to study the effect of different tin amounts on the anatase–rutile phase transition. It was found that the introduction of ions increases the thermal stability of anatase modifications. The material’s photocatalytic activity was studied in reaction with a model pollutant (methylene blue) photodegradation under UV and visible light activation. The best photocatalytic properties were shown for material, which contains 5[Formula: see text]mol.% of Sn.

scholarly journals Thermal, ferroelastic, and structural properties near phase transitions of organic–inorganic perovskite type [NH3(CH2)3NH3]CdBr4 crystals

RSC Advances ◽  
2021 ◽  
Vol 11 (29) ◽  
pp. 17622-17629
Author(s):  
Ae Ran Lim
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Thermal Behavior ◽  
Structural Properties ◽  
Structural Dynamics ◽  
Transition Temperatures ◽  
Inorganic Perovskite ◽  
Phase Transition Temperatures ◽  
Perovskite Type

We studied the thermal behavior and structural dynamics of [NH3(CH2)3NH3]CdBr4 near phase transition temperatures.

Triply-responsive OEG-based microgels and hydrogels: Regulation of swelling ratio, volume phase transition temperatures and mechanical properties

2021 ◽  
Author(s):  
Dongdong Lu ◽  
Mingning Zhu ◽  
Jing Jin ◽  
Brian R. Saunders
Keyword(s):  
Phase Transition ◽  
Biomedical Engineering ◽  
Volume Phase Transition ◽  
Swelling Ratio ◽  
Transition Temperatures ◽  
Ph Responsive ◽  
Network Systems ◽  
Volume Phase ◽  
Phase Transition Temperatures ◽  
Volume Swelling

Thermally- and pH-responsive microgels (MGs) and hydrogels are fascinating network systems that have been applied in biomedical engineering and sensing. The volume-swelling ratio (Q) and the volume-phase transition temperatures (VPTTs)...

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