Mechanical Properties of Polymers: The Influence of Molecular Weight and Molecular Weight Distribution

Martin, John R.; Johnson, Julian F.; Cooper, Anthony R.

doi:10.1080/15321797208068169

Cited by 180 publications

(44 citation statements)

References 162 publications

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“…The PAAs in their studies were conventional aqueous solutions with M n ranging between 5 K and 200 K. They have suggested, in line with the observations of Martin et al [74], that the critical M w would be approximately 80 K, lower than that (100 K) suggested by Hill et al [30] and based on work by Prentice [59]. Additionally, Dowling and Fleming [23] suggested the entanglement M w for PAA to be below 5 K, for aqueous PAAs, compared with the 7 K suggested by Hill et al [30] for anhydrous PAAs.…”

supporting

confidence: 76%

The role of poly(acrylic acid) in conventional glass polyalkenoate cements

Alhalawani

Curran

Boyd

et al. 2015

Journal of Polymer Engineering

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Abstract Glass polyalkenoate cements (GPCs) have been used in dentistry for over 40 years. These novel bioactive materials are the result of a reaction between a finely ground glass (base) and a polymer (acid), usually poly(acrylic acid) (PAA), in the presence of water. This article reviews the types of PAA used as reagents (including how they vary by molar mass, molecular weight, concentration, polydispersity and content) and the way that they control the properties of the conventional GPCs (CGPCs) formulated from them. The article also considers the effect of PAA on the clinical performance of CGPCs, including biocompatibility, rheological and mechanical properties, adhesion, ion release, acid erosion and clinical durability. The review has critically evaluated the literature and clarified the role that the polyacid component of CGPCs plays in setting and maturation. This review will lead to an improved understanding of the chemistry and properties of the PAA phase which will lead to further innovation in the glass-based cements field.

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supporting

confidence: 76%

The role of poly(acrylic acid) in conventional glass polyalkenoate cements

Alhalawani

Curran

Boyd

et al. 2015

Journal of Polymer Engineering

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“…Previous work by Harman (1949) using curing cycles that produced a greater range of residual monomer concentrations than in this study showed that transverse bend strength was also proportional to residual monomer concentration. Martin, Johnson & Cooper (1973) have shown that the properties of polymethylmethacrylate are dependent on the distribution of the polymer chains below a molecular weight of 10^. Above this molecular weight no change in properties can be observed unless a large proportion of low molecular weight material is present.…”

Section: Discussionmentioning

confidence: 99%

Effect of the curing cycle on some properties of a polymethylmethacrylate denture base material

Jagger¹

1978

J of Oral Rehabilitation

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The properties of a denture base material may be modified by altering both the temperature and the time of heating during the curing cycle. In this study a polymethylmethacrylate denture base containing no crosslinking agent was polymerised using four different curing cycles. The structure of the materials so obtained was investigated by an acid etching technique. The materials were characterized with respect to degree of cure, strength and water sorption. It was concluded that: 1. No correlation was observed between the curing cycles and polymer structure. 2. The curing cycle of 7 h at 70 degrees C plus 1 h at 100 degrees C produced best indentation strength and tensile strength. 3. A correlation was observed between residual monomer, indentation resistance, tensile strength and water sorption. This suggested that residual monomer concentration is the most important parameter in the determination of the properties of the material investigated in this study.

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“…While this may be true for some properties, such as Tg or possibly modulus, it does not hold for ultimate properties such as fatigue endurance [14,15,[74][75][76]. Also, various literature references indicate that increasing molecular weight also increases craze strength, creep resistance, and endurance under long-time steady loading [3,77].…”

Section: B Molecular Weightmentioning

confidence: 93%

Fatigue of polymers

1980

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The general nature of fracture in polymers, when subject to alternating loads as distinct from static or steadily increasing loads, is reviewed; and the molecular mechanisms and micromechanics aspects of the fatigue fracture process are discussed. Some attention is given to thermal fatigue, where fracture results primarily from a large specimen temperature rise due to hysteresis heating. However, primary emphasis is devoted to mechanical fatigue, in which fracture is a result of initiation and propagation of a crack, as a result of the periodic nature of the applied load.Attention is given to the important internal, or material, variables such as polymer structure, molecular weight, crosslinking, and filler or diluent type and content; and to significant external variables such as stress or stress intensity factor amplitude, mean stress, temperature, frequency and environment. Various methods that can be utilized to provide significant degrees of enhancement in the fatigue resistance of polymers are outlined and discussed.

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Mechanical Properties of Polymers: The Influence of Molecular Weight and Molecular Weight Distribution

Cited by 180 publications

References 162 publications

The role of poly(acrylic acid) in conventional glass polyalkenoate cements

The role of poly(acrylic acid) in conventional glass polyalkenoate cements

Effect of the curing cycle on some properties of a polymethylmethacrylate denture base material

Fatigue of polymers

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