摘要:

AbstractThe formation and agglomeration of PVC primary particles were studied in bulk polymerization experiments. In the absence of additives, the primary particles started to agglomerate at low conversions. The agglomeration conversion, as well as the size of the agglomerated particles, decreased when the agitation speed increased. At the highest speed tested, the agglomeration started already at 0.05 percent conversion. The primary particle size was about 0.16‐0.18 μm, and seemed to be constant in the conversion interval studied (up to 5 percent). This indicated that the nucleation rate of primary particles was almost constant and that the growth rate of agglomerated particles was very low. The addition of sorbitan monolaurate produced a decrease in primary particle size. Polymeric additives such as PMMA, EVA, and PVAc stabilized primary particles against agglomeration but had no marked effect on the primary particle size. The monomer‐soluble fraction of poly(vnyl alcohol‐b‐vinyl acetate) with high content acetate groups did not affect either the particle size or the agglomeration

ISSN:0193-7197    

DOI:10.1002/vnl.730040202

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractVinyl chloride‐ethylene copolymers containing from 1.0 to 5.5 wt.% ethylene were synthesized and compounded with DOP plasticizer at levels of 0, 5, 10, 20, 30, and 40 parts per hundred parts of resin. Physical property tests indicated that, as an internal plasticizer, ethylene was 2 to 3 times more efficient than DOP in the range studied. An examination of room temperature modulus as well as brittleness also indicated that crystallinity was still apparent in all copolymer

ISSN:0193-7197    

DOI:10.1002/vnl.730040203

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040204

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040205

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040206

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040207

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040208

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractPVC is a notch‐sensitive polymer. The drop weight impact strength is also lost dramatically below 0°C. This requires special formulation considerations for critical applications. The general trend is to use polymeric impact modifiers, which are rubbery, graft polymers or blends of both hard and rubbery materials. This is achieved with some sacrifice in flexural modulus and formulation economics. A recent study conducted to relate calcium carbonate particle size with notched Izod and low‐temperature drop weight impact strength has shown that the stearate‐coated Ultrafine precipitated calcium carbonate (0.07 μ), at 15 phr loading, substantially improves both properties without sacrifice in flexural modulus. The formulation cost is also favorable. It is hypothesized that improvement in the above properties is primarily due to uniform stress distribution and lack of defect structure, as observed with coarse fillers. Surprisingly, the optimum‐particle‐size, coated, precipitated calacium carbonates also improved the Ultraviolet light stability

ISSN:0193-7197    

DOI:10.1002/vnl.730040209

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730040201

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY