Structure and Strength at Immiscible Polymer Interfaces

Ge, Ting; Grest, Gary S.; Robbins, Mark O.

doi:10.1021/mz400407m

Cited by 39 publications

(94 citation statements)

References 39 publications

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“…31 A simple quartic potential with the same equilibrium spacing was used in the mechanical tests since chain scission plays an essential role in failure. As in past simulations, 6,7,18,30,32 the breaking force for the quartic potential, 240u 0 /a, is 100 times higher than that for the intermolecular LJ potential. This ratio is consistent with experimental estimates.…”

Section: Simulation Model and Methodologysupporting

confidence: 73%

“…To limit excluded volume effects, we use a modification of the original PPA algorithm where the diameter of repulsive interactions between chains is then reduced by a factor of four and the contour is minimized again. 6,18,45 The resulting configuration is a network of primitive paths for each chain.…”

Section: Simulation Model and Methodologymentioning

confidence: 99%

“…[4][5][6][8][9][10][11][12][13][14][15][16][17][18] Experiments 4,8,9 have found a correlation between the mechanical strength and the interfacial width. For homopolymers, the growth of interfacial width with time has been explained using reptation theory.…”

Section: Introductionmentioning

confidence: 97%

“…18 The maximum shear stress before failure σ max was evaluated using a geometry that mimics a lap-joint shear experiment. [21][22][23][24] As in experi-ments, 21 we found that σ max rose with welding time t as t 1/4 and saturated long before polymers had diffused by their radius of gyration.…”

Section: Introductionmentioning

confidence: 99%

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Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements, and Crazing

Grest

Robbins

2014

Macromolecules

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Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time t. Changes in the tensile stress, mode of failure and interfacial fracture energy G I are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small t welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy G I is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, G I increases as * To whom correspondence should be addressed † Johns Hopkins University ‡ University of North Carolina ¶ Sandia National Laboratories 1 arXiv:1410.1917v1 [cond-mat.soft] 7 Oct 2014 t 1/2 before saturating at the average bulk fracture energy G b . As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, G I is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and

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Section: Simulation Model and Methodologysupporting

confidence: 73%

Section: Simulation Model and Methodologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements, and Crazing

Grest

Robbins

2014

Macromolecules

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“…[ 23,25 ] However, numerous studies have shown that the adhesion between poorly miscible polymers, such as PGMA-PAS, or use of short linkers (ethylene diamine) are generally weak due to poor chain diffusion and localized stress concentration. [ 29,[42][43][44] The symmetric PGMA-PGMA interface employed in our studies enables diffusion and chain entanglement of polymer chains between the fi lms, which are important factors to realize higher adhesion energies. [ 40 ] Together with the crosslinking ability of iCVD PGMA, moderate thermal treatments enabled us to tailor the crack-propagation interface in bonded substrates.…”

Section: Transitions In Film Adhesive Properties Characterized By Posmentioning

confidence: 99%

Wafer Scale Solventless Adhesive Bonding with iCVD Polyglycidylmethacrylate: Effects of Bonding Parameters on Adhesion Energies

Jeevendrakumar

Pascual

Bergkvist

2015

Adv Materials Inter

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heterogeneous 3D bonding of different materials, [8][9][10][11][12] in which temporary/permanent wafer bonding and wafer thinning processes are integral processes to realize such 3D architectures. [13][14][15] Polymers are the preferred adhesive materials due to their ease of handling, chemical and physical modifi cation, mild processing conditions, and compatibility with standard semiconductor processing. [ 5,16,17 ] Such adhesive fi lms are most commonly applied to wafer substrates by spin coating, owing to its low cost, simplicity, and high throughput. However, use of solvents poses certain limitations with substrate compatibility, solvent outgassing, and conformal coatings. This could result in void trapping at the interface and compromise the integrity and reliability of the formed bond. [ 5,17,18 ] Additional solvent bake-out and cure steps are needed to minimize such solvent effects, which increases processing time and can negatively impact the chemical/mechanical properties of the adhesive. [ 16 ] Deposition of polymers via gas-phase methods is an attractive alternative to negate issues with solvents and textured substrates. Among polymeric chemical vapor deposition (CVD) techniques, initiated CVD (iCVD) has gained signifi cant attention in the last decade, owing to its performance characteristics such as retention of polymer functionality, good conformity, and substrate insensitivity. [ 19,20 ] Unlike plasma-enhanced CVD, iCVD follows similar reaction mechanisms as bulk polymerization, in that linear, noncrosslinked polymer chains can be formed. [ 21 ] Recently, CVD polymer thin fi lms were explored as alternative materials for solventless adhesive bonding (SAB) of microfl uidic devices. [22][23][24][25][26] The SAB technology has potential for void-free bonding of larger substrates, with additional advantages including the ability to bond dissimilar and patterned substrates, which is critical for heterogeneous integration. [ 22 ] We are interested in investigating the adhesive properties of iCVD polymers and evaluating the feasibility of using iCVD nanometer thin fi lms for wafer-scale bonding, focusing on 300 mm silicon substrates (the current standard wafer size for IC production). To that end, 200-250 nm thick iCVD polyglycidylmethacrylate (PGMA) fi lms were deposited on 300 mm Initiated chemical vapor deposition (iCVD) polyglycidylmethacrylate (PGMA) thin fi lms are investigated as adhesives for wafer-scale bonding of 300 mm silicon substrates and demonstrated to form highly uniform, void-free bond interfaces. The effects of bonding temperature and pressure on critical adhesion energy ( G c ) between iCVD PGMA and silicon are studied using the fourpoint bend technique. G c values can be varied over an order of magnitude (0.59-41.6 J m −2 ) by controlling the bonding temperature and the observed dependence is attributed to changes in the physical (diffusion) and chemical (crosslinking) properties of the fi lm. Thermal degradation studies using spectroscopic ellipsometry reveal that the iCVD PGMA fi l...

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Microstructural investigation of butt‐fusion joint in high‐density polyethylene pipes using wide‐ and small‐angle X‐ray scattering

Kang

Choi

Song

2017

J of Applied Polymer Sci

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The melt fusion zone (MFZ) of polyethylene pipe was investigated employing synchrotron wide-and small-angle X-ray scattering at various locations in MFZ by changing X-ray incidence angles to probe three-dimensional structural features. It was determined that the crystals were oriented in two different modes. One is that the polymer chains are oriented parallel to the joint interface line consistently throughout the MFZ. The other is that the crystals are oriented in particular directions depending on the positions in MFZ. The combination of pressure and melt flow during joining process resulted in such a complex structure. It was notable that the boundary of MFZ against the base material was found to be very different depending on the structures involved such as crystallographic unit orientation, lamellae orientation, crystallinity, and spherulitic morphology. V C 2017 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2018, 135, 45668.

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Structure and Strength at Immiscible Polymer Interfaces

Cited by 39 publications

References 39 publications

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements, and Crazing

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements, and Crazing

Wafer Scale Solventless Adhesive Bonding with iCVD Polyglycidylmethacrylate: Effects of Bonding Parameters on Adhesion Energies

Microstructural investigation of butt‐fusion joint in high‐density polyethylene pipes using wide‐ and small‐angle X‐ray scattering

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