Effect of vegetable-based polyols in unimodal glass-transition polyurethane slabstock viscoelastic foams and some guidance for the control of their structure-property behavior. I

2010 ◽  
Vol 119 (5) ◽  
pp. 2683-2697 ◽  
Author(s):  
Benjamin R. Vaughan ◽  
Garth L. Wilkes ◽  
Dimitrios V. Dounis ◽  
Cam McLaughlin
Keyword(s):  
Glass Transition ◽  
Structure Property ◽  
Viscoelastic Foams

Prediction of glass transition temperatures of polyacrylates from the structures of motion units

2016 ◽  
Vol 15 (02) ◽  
pp. 1650011 ◽  
Author(s):  
Xinliang Yu ◽  
Xianwei Huang
Keyword(s):  
Glass Transition ◽  
Molecular Descriptors ◽  
Amorphous Polymer ◽  
External Validation ◽  
Data Sets ◽  
Structure Property ◽  
Internal Validation ◽  
The Stability ◽  
Leave One Out ◽  
Mlr Model

The glass transition temperature [Formula: see text] is the most important parameter of an amorphous polymer. A quantitative structure-property relationship (QSPR) was developed for [Formula: see text]s of 82 polyacrylates, by applying stepwise multiple linear regression (MLR) analysis. Molecular descriptors used to describe polymer structures were, for the first time, calculated from the motion units of polymer backbones, which are chain segments with 20 carbons in length (10 repeating units). After internal validation with leave-one-out (LOO) method, external validation was carried out to test the stability of the MLR model of [Formula: see text]s. Compared to the models already published in the literature, the MLR model in this paper was accurate and acceptable, although our model was based on bigger data sets. The feasibility of calculating molecular descriptors from the motion units of polymer backbones for developing [Formula: see text] models of polyacrylates has been demonstrated.

Structure-Property Relationship in Rubber-Modified Propylene-Ethylene Block Copolymer Blends

1988 ◽  
Vol 61 (5) ◽  
pp. 747-759 ◽  
Author(s):  
M. M. Sain ◽  
I. Hudec ◽  
J. Beniska ◽  
P. Rosner
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Block Copolymer ◽  
Strong Interaction ◽  
Transition Temperatures ◽  
Structure Property ◽  
Glass Transition Temperatures ◽  
Copolymer Blends ◽  
Structure Property Relationship ◽  
Plastic Components

Abstract The incorporation of a phase modifier, as is well known in the case of elasto-plastic blends, leads to an improvement of mechanical properties and brittleness character for PRP-EVA blends. Similarly, the influence of a cocuring agent and a phase modifier on NR-PRP blends also improved the mechanical properties. Although the modification of the PRP-EVA blend has very little influence on glass transition temperatures, the NR-PRP blends show a measurable shift in their glass-transition temperatures. It is demonstrated that strong interaction occurs between the elastic and plastic components of the blends. Further, it has been shown that this interaction is responsible for improved properties of the blends over that of the pure polymer components.

Polyetherimides—synthesis and structure-property relationships

1993 ◽  
Vol 5 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Martin Davies ◽  
John N Hay ◽  
Barry Woodfine
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Thermal Properties ◽  
Structure Property ◽  
Polymer Molecular Weight ◽  
Chain Flexibility ◽  
Structure Property Relationships ◽  
Polymer Properties ◽  
Synthetic Routes ◽  
Rotational Freedom

Polyetherimides have been synthesized by two complementary routes starting from 4-halophthalic anhydride. A range of polymers has been prepared by varying the structure of the diamines and bisphenols employed in the syntheses. These polymers have been characterized by their m spectra, molecular weight and thermal properties. The applicability and limitations of the synthetic routes are discussed. Structure-property (glass transition temperature, Tg relationships are elucidated and discused in terms of the structural fragments in the polymer chain. Chain flexibility, rotational freedom and inter-chain interactions are all important parameters affecting the polymer properties. The effect of polymer molecular weight on Tg is also discussed.

Structure-Property Relationships in Elastomer-Modified Terpolymer Systems

1971 ◽  
Vol 44 (1) ◽  
pp. 62-70
Author(s):  
E. M. Hagerman
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Impact Resistance ◽  
Acrylonitrile Butadiene Styrene ◽  
Matrix Composition ◽  
Structure Property ◽  
Constant Matrix ◽  
Izod Impact

Abstract A number of terpolymers, incorporating as the elastomer phase polybutadiene, polyisoprene, poly-2,3-dimethylbutadiene, poly(butadiene-co-styrene), and poly(butadiene-co-2-methyl-5-vinylpyridine), were studied. Matrices were composed of poly(styrene-co-aerylonitrile) (SAN), poly(α-methylstyrene-eo-acrylonitrile), and poly(styrene-co-acenaphthylene). At constant elastomer content and elastomer molecular weight in systems employing a SAN matrix, Izod impact resistance was found to vary inversely with rising elastomer-glass transition temperature. In systems of various matrix composition, using a polybutadiene elastomer, heat deflection temperatures were found to vary directly and impact resistance inversely with rising matrix-glass transition temperature. In acrylonitrile-butadiene-styrene (ABS), systems of constant matrix composition and elastomer content, varying the elastomer molecular weight from 0.6 to 2.6×105 resulted in increasing the Izod impact resistance from 0.67 to 12.8 ft-1b/in. of notch.

Synthesis and properties of polyimides derived from bis(4-aminophenyl)isohexides

2016 ◽  
Vol 29 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Xiaodong Ji ◽  
Jingling Yan ◽  
Xiuju Liu ◽  
Zikun Wang ◽  
Zhen Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Glass Transition ◽  
Physical And Mechanical Properties ◽  
Amic Acid ◽  
Systematic Investigation ◽  
Structure Property ◽  
Free Standing ◽  
Structure Property Relationship ◽  
Relationship Of

Several partially bio-based polyimides have been successfully synthesized by polycondensation between bis(4-aminophenyl)isohexides with various commercial dianhydrides. Flexible and free-standing films were readily obtained from their poly(amic acid) or polyimide solutions. A systematic investigation of the structure–property relationship of polyimides highlights the significant impact of the isohexides moieties on their physical and mechanical properties (glass transition temperature, inherent viscosity, thermal stability, solubility, and mechanical properties). The results revealed that these polyimides exhibited comparable thermal stability and mechanical properties to those of petrochemical-based ones.

scholarly journals Predicting Polymer’s Glass Transition Temperature by A Chemical Language Processing Model

2021 ◽  
Author(s):  
Guang Chen ◽  
Lei Tao ◽  
Ying Li
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Language Processing ◽  
High Throughput Screening ◽  
Molecular Descriptors ◽  
Feature Representation ◽  
Structure Property ◽  
Repeat Units ◽  
Chemical Language

We propose a chemical language processing model to predict polymers’ glass transition temperature (Tg) through a polymer language (SMILES, Simplified Molecular Input Line Entry System) embedding and recurrent neural network. This model only receives the SMILES strings of polymer’s repeat units as inputs and considers the SMILES strings as sequential data at the character level. Using this method, there is no need to calculate any additional molecular descriptors or fingerprints of polymers, and thereby, being very computationally efficient and simple. More importantly, it avoids the difficulties to generate molecular descriptors for repeat units containing polymerization point `*’. Results show that the trained model demonstrates reasonable prediction accuracy on unseen polymer’s Tg. Besides, this model is further applied for high-throughput screening on an unlabeled polymer database to identify high-temperature polymers that are desired for applications in extreme environments. Our work demonstrates that the SMILES strings of polymer’s repeat units can be used as an effective feature representation to develop a chemical language processing model for predictions of Tg. The framework of this model is general and can be used to construct structure-property relationships for other polymer’s properties.

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