Study on Mechanical Properties of Polyurethane Elastomers for Drum Scraper

2011 ◽  
Vol 284-286 ◽  
pp. 2384-2387
Author(s):  
Jin Cui Zhang ◽  
Xi Jun Liu ◽  
Tie Ning Ma
Keyword(s):  
Mechanical Properties ◽  
Chain Extender ◽  
Glycol Ether ◽  
Toluene Diisocyanate ◽  
Chain Extension ◽  
Molar Ratio ◽  
Casting Method ◽  
Polyurethane Elastomers ◽  
Application Requirements

Polyurethane elastomers (PUE) were prepared by casting method using the prepolymer and the chain extender. In here, the prepolymer synthesized by using poly(tetramethylene glycol ether) (PTMG) and toluene diisocyanate (TDI), the chain extender was a mixture of 3,5-dimetylthio toluene diamine (E-300) and triethanolamine. The effects of the NCO concentration in prepolymer, the molar ratio of E-300/triethanolamine, and the chain extension coefficient of NCO/NH2 on the mechanical properties of the prepared PUE were studied. The results showed that the prepared PUE possesses excellent mechanical properties which can meet the drum scraper’s application requirements when the NCO concentration in prepolymer was 5.06% and the molar ratio of composite chain extender was 0.92/0.08.

Preparation and Mechanical Properties of Polyurethane Elastomer with Two Soft Segments of HTPB/PTMG

2010 ◽  
Vol 150-151 ◽  
pp. 1689-1692 ◽  
Author(s):  
Hai Tao Tao ◽  
Xi Jun Liu ◽  
Tie Ning Ma
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Molecular Weight ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Chain Extender ◽  
Toluene Diisocyanate ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Polyurethane Elastomers

In this paper, a series of polyurethane elastomers (PUE) were prepared employing casting method using toluene diisocyanate (TDI), hydroxy-terminated butadiene-acrylonitrile copolymer(HTBN) and polytetrahydrofuran glycol (PTMG) as the main raw materials, and using 2,4- and 2,6- dimethylthioaromatic diamine (DMTDA) as a chain extender. The effects of the content of NCO in PUE (NCO%), mass ratio of HTBN/PTMG, molecular weight of PTMG, dosage of chain extender and heat treatment on the mechanical properties of PUE were studied. The results showed that the lower molecular weight of PTMG and the higher heat treatment temperature were both favorable for increasing the mechanical properties of PUE. When the mass ratio of HTBN/PTMG was 35:65, NCO% was 6.0%, molar ratio of NCO/NH2 was 1.20 and heat treatment time was 2h at 115 , the mechanical properties of PUE were best.

scholarly journals Crystallization, Structure and Significantly Improved Mechanical Properties of PLA/PPC Blends Compatibilized with PLA-PPC Copolymers Produced by Reactions Initiated with TBT or TDI

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3245
Author(s):  
Lixin Song ◽  
Yongchao Li ◽  
Xiangyu Meng ◽  
Ting Wang ◽  
Ying Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Average Molecular Weight ◽  
Toluene Diisocyanate ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Cooling Process ◽  
Material Degradation ◽  
Elongation At Break ◽  
Poly Propylene

Poly (lactic acid) (PLA)-Poly (propylene carbonate) (PPC) block copolymer compatibilizers are produced in incompatible 70wt%PLA/PPC blend by initiating transesterification with addition of 1% of tetra butyl titanate (TBT) or by chain extension with addition of 2% of 2,4-toluene diisocyanate (TDI). The above blends can have much better mechanical properties than the blend without TBT and TDI. The elongation at break is dramatically larger (114% with 2% of TDI and 60% with 1% of TBT) than the blend without TDI and TBT, with a slightly lower mechanical strength. A small fraction of the copolymer is likely formed in the PLA/PPC blend with addition of TBT, and a significant amount of the copolymer can be made with addition of TDI. The copolymer produced with TDI has PPC as a major content (~70 wt%) and forms a miscible interphase with its own Tg. The crystallinity of the blend with TDI is significantly lower than the blend without TDI, as the PLA blocks of the copolymer in the interphase is hardly to crystallize. The average molecular weight increases significantly with addition of TDI, likely compensating the lower mechanical strength due to lower crystallinity. Material degradation can occur with addition of TBT, but it is very limited with 1% of TBT. However, compared with the blends without TBT, the PLA crystallinity of the blend with 1%TBT increases sharply during the cooling process, which likely compensates the loss of mechanical strength due to the slightly material degradation. The added TDI does not have any significant impact on PLA lamellar packing, but the addition of TBT can make PLA lamellar packing much less ordered, presumably resulted from much smaller PPC domains formed in the blend due to better compatibility.

Application of bis(glycidyloxy)phenylphosphine oxide as a chain extender for polyamide-6

RSC Advances ◽  
2015 ◽  
Vol 5 (40) ◽  
pp. 31878-31885 ◽  
Author(s):  
Alvianto Wirasaputra ◽  
Jianqing Zhao ◽  
Yaming Zhu ◽  
Shumei Liu ◽  
Yanchao Yuan
Keyword(s):  
Mechanical Properties ◽  
Small Molecule ◽  
Polyamide 6 ◽  
Chain Extender ◽  
Chain Extension ◽  
A Chain ◽  
Phenylphosphine Oxide

Figure melt torque of PA6 mixed with different contents of chain extender BGPPO. The addition of small molecule diepoxide (BGPPO) greatly enhanced the melt torque, rheological and mechanical properties of polyamide-6 through chain extension reaction.

scholarly journals Influence of Chain-Extension Reaction on Stereocomplexation, Mechanical Properties and Heat Resistance of Compressed Stereocomplex-Polylactide Bioplastic Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1218 ◽  
Author(s):  
Yodthong Baimark ◽  
Sumet Kittipoom
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Heat Resistance ◽  
Tensile Testing ◽  
Chain Extender ◽  
Chain Extension ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Patterns

Stereocomplex polylactide (scPLA) films were prepared by melt blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) with and without an epoxy-based chain extender before compression molding. The obtained scPLA films were characterized through differential scanning calorimetry, X-ray diffractometry (XRD), tensile testing and dimensional stability to heat. XRD patterns revealed that all the scPLA films had only stereocomplex crystallites. The obtained results showed that the chain-extension reaction improved mechanical properties of the scPLA films, however, it suppressed stereocomplexation and heat resistance.

Influence of Diisocyanates on Dynamic Mechanical Properties of Castable Polyurethane Elastomers

2012 ◽  
Vol 217-219 ◽  
pp. 563-566
Author(s):  
Xiao Dong Chen ◽  
Yu Hua Yi
Keyword(s):  
Mechanical Properties ◽  
Dynamic Mechanical Analysis ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Toluene Diisocyanate ◽  
Diphenylmethane Diisocyanate ◽  
Analysis Method ◽  
Polyurethane Elastomers ◽  
Dynamic Mechanical ◽  
Soft Segments

A series of castable polyurethane elastomers, based on polytetramethylene glycol as soft segments and toluene diisocyanate, 4, 4’-diphenylmethane diisocyanate, P-phenylene diisocyanate as diisocyanates respectively, were synthesized. The dynamic mechanical analysis method was utilized to determine tan delta property (tanδ). Also the influence of diisocyanates on the dynamic mechanical properties of castable polyurethane elastomers was analyzed. It can be concluded that the P-phenylene diisocyanate system elastomers have the most excellent dynamic mechanical properties.

scholarly journals The Green Approach to the Synthesis of Bio-Based Thermoplastic Polyurethane Elastomers with Partially Bio-Based Hard Blocks

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2334
Author(s):  
Ewa Głowińska ◽  
Paulina Kasprzyk ◽  
Janusz Datta
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Viscoelastic Behavior ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Chain Extender ◽  
Sustainable Chemistry ◽  
Polyurethane Elastomers ◽  
Thermoplastic Polyurethane Elastomers ◽  
Hard Segments

Bio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal, thermomechanical, and mechanical properties of obtained bio-TPUs. Diisocyanate mixture and bio-based 1,4-butanediol (as a low molecular chain extender) created bio-based hard blocks (HS). The diisocyanate mixture contained up to 75 wt % of partially bio-based diisocyanate. It is worth mentioning that the structure and amount of HS impact the phase separation, processing, thermal or mechanical properties of polyurethanes. The soft blocks (SS) in the bio-TPU’s materials were built from α,ω-oligo(ethylene-butylene adipate) diol. Hereby, bio-TPUs differed in hard segments content (c.a. 30; 34; 40, and 53%). We found that already increase of bio-based diisocyanate content of the bio-TPU impact the changes in their thermal stability which was measured by TGA. Based on DMTA results we observed changes in the viscoelastic behavior of bio-TPUs. The DSC analysis revealed decreasing in glass transition temperature and melting temperature of hard segments. In general, obtained materials were characterized by good mechanical properties. The results confirmed the validity of undertaken research problem related to obtaining bio-TPUs consist of bio-based hard building blocks. The application of partially bio-based diisocyanate mixtures and bio-based chain extender for bio-TPU synthesis leads to sustainable chemistry. Therefore the total level of “green carbons” increases with the increase of bio-based diisocyanate content in the bio-TPU structure. Obtained results constitute promising data for further works related to the preparation of fully bio-based thermoplastic polyurethane elastomers and development in the field of bio-based polymeric materials.

Chain Extension of Poly(butylene adipate) with 2,2’-(1,4- Phenylene)-bis(2-oxazoline)

2006 ◽  
Vol 11-12 ◽  
pp. 387-390 ◽  
Author(s):  
Si Yang Luo ◽  
Yu Zhang ◽  
Jing Bo Zhao
Keyword(s):  
Molecular Weight ◽  
Influencing Factors ◽  
1H Nmr ◽  
Reaction Temperature ◽  
Chain Extender ◽  
Chain Extension ◽  
Molar Ratio ◽  
Low Molecular Weight ◽  
Melt Polycondensation

Low molecular weight poly(butylene adipate) (PBA) was synthesized by melt polycondensation. The chain extension of the prepolymers was carried out using 2,2’-(1,4-phenylene)-bis(2-oxazoline) (PBOX) as chain-extender. The influencing factors including reaction temperature, oxazoline/-COOH molar ratio, and the molecular weight of prepolymers were studied. At the optimal chain-extending condition, PBA with Mn of 38583 and Mw of 125497 was prepared. The structure of the chain-extended PBA was also characterized by the FTIR and 1H NMR.

scholarly journals The flame retardancy and rheological properties of PA6/MCA modified by DOPO-based chain extender

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19593-19603 ◽  
Author(s):  
Jianan Cai ◽  
Alvianto Wirasaputra ◽  
Yaming Zhu ◽  
Shumei Liu ◽  
Yubin Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rheological Properties ◽  
Flame Retardancy ◽  
Chain Extender ◽  
Chain Extension ◽  
P Addition

Addition of DOPO-based chain extender (DEP) simultaneously enhanced the flame retardancy and mechanical properties of PA6/MCA through chain extension and coaction in flame-retarding.

Effect of the Starting NCO/OH Molar Ratio on the Structure and Properties of Polyurethane

2011 ◽  
Vol 415-417 ◽  
pp. 1261-1264
Author(s):  
Yu Hua Yi ◽  
Hao Shi
Keyword(s):  
Mechanical Properties ◽  
Microphase Separation ◽  
Dynamic Mechanical Properties ◽  
Toluene Diisocyanate ◽  
Molar Ratio ◽  
Structure And Properties ◽  
Dynamic Mechanical ◽  
Compression Set

The present study described the effect of the starting NCO/OH molar ratio on the structure and properties of castable polyurethanes based on polytetrahydrofuran glycol (PTMG) and 2,4- toluene diisocyanate (TDI). The structural was tested by SEM. The result showed that higher starting NCO/OH molar ratio can lead to higher degree of microphase separation, decrease the compression set and improve the dynamic mechanical properties.

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