Synthetic polymers and latex have been widely used in an array of applications such as packaging and coatings, construction materials, consumer electronics, medical equipment and agriculture. The recently staged Latex and Synthetic Polymer Dispersions conference, held in Kuala Lumpur, Malaysia, highlighted development studies and innovations for a modestly growing sector that is banking on demand, according to Angelica Buan.
US research firm Kline & Company expects the synthetic latex polymers industry to grow by 10% this year. Based on its study, the European Union (EU) is the second largest consumer after the US, and in 2011, the combined consumption of the 27 states in the EU was close to 2.5 million dry tonnes of latex polymers, valued at over EUR6 billion.
It adds that polymer dispersion consumption in Eastern Europe, Russia, and Turkey is significantly smaller than the major EU states, yet these regions show potential for growth. Demand will be spurred by applications for paper, paints and coatings as well as adhesives and sealants. Nonetheless, growth rates differ and in general, growth will be moderate over the next few years, says the Kline report.
REACH a driving force
While in some cases stringent regulations serve as obstacles for development, such is not the case with the implementation of Europe’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) programme for polymers. Also, the United Nations globally harmonised system (UN GHS) is used for classification and labelling of chemicals in Europe.
The goal for the REACH initiative is to uplift and consolidate the knowledge base of the European SME polymer industry, especially since the initiative encompasses application of novel techniques, new technologies and innovative instruments and methods that offer environmental as well as economic advantages to the industry.
Compliance with the REACH initiative has resulted in various modifications in the use of substances covered by the regulation. For instance, in Europe, water-based paints are replacing solventbased paints in the market, thus boosting favourable demand for synthetic latex polymers.
Latching on to advancements for future growth
Applications for polymer dispersions and latices are varied. The water-based mixtures/ preparations are used as binder, primarily in paints, surface coatings, adhesives, non-wovens, plasters and carpet backing. They also find applications in paper and textile sectors as finishing agents.
The 8th Smithers Rapra conference on Latex and Synthetic Polymer Dispersions, held in Kuala Lumpur from 10-11 September, gave the 140+ delegates a broad picture of the industry.
Amongst the experts who shared technical insights on the various facets of the sector was Professor Ho Chee Cheong, an adjunct professor at the University Tunku Abdul Rahman, Malaysia. He described the scientific principles underlying latex dipping and the pre-requisites for a barrier device for gloves, as part of his talk on the influence of surface phenomena on the latex dipping process for gloves. He says that the essential part of gloves, which is the latex (as the material), should be able to form a continuous film and be resistant to any pathogens to efficiently render a barrier device to the gloves.
“The material should be soft and conform to the contour of the hand,” he said, adding that it should also give a good working surface so that it can provide the wearer with the necessary grip.
Ho emphasised the non-deformable requisite. “The material for the gloves must be mechanically strong enough for it to be stretched and elastic enough for it to return to its original shape,” he said. Furthermore, he said that the material should exhibit low surface friction to enable the wearer’s hand to slide easily into the glove. An important aspect of Ho’s topic is that latex needs to be able to form a film, and thereby, the particles of the latex must be fused together to form a continuous film.
Another expert, Aik Hwee Eng of glove maker Ansell, discussed about the production of an antimicrobial glove via a modern dipping method.
According to Joseph L. Keddie and Alexander Francis Routh in the paper titled “Fundamentals of Latex Film Formation”, the processing of latex film involves several steps “from dilution through to concentrated dispersion into a packed array of particles and eventually into a continuous polymer film.” The process is split into three steps: drying, particle deformation and diffusion.
The environmental side of the industry was covered by two presentations from the Malaysian Rubber Board (MRB). Muhammad Syaarani Danya presented comparison works involving complexometric titration (a form of volumetric analysis in which the formation of a coloured complex is used to indicate the end point of a titration) of magnesium content in field and concentrated latices by using KCN (potassium cyanide). He added that cyanide-free compound as masking agents can be used instead.
Also from MRB, Dr Devaraj Veerasamy presented the use of ultrafiltration to process latex. In a similar vein, Professor Khairah Haji Badri, of the Universiti Kebangsaan Malaysia (UKM), showed how natural resources such as palm oil can be used to create useful polymers. She said the latest development in a pre-vulcanisation technique to produce rubber-like polyurethane from palm kernel oil. The innovation has been produced at UKM’s 500 kg/cycle-capacity pilot plant.
She says that the rising cost of petrol in Malaysia was one reason why the research department was prompted to develop the alternative synthetic material from sustainable materials. And since palm oil is abundant in the country, her team utilised it for the project. Badri also said that the basic reactant, the palm-based ester, is already in a pre-commercialisation phase.
Hardi Tamm of Estonia-based Korymbos, a research and technology development company, touched on the allergenic potential of synthetic latex gloves versus those dipped in natural rubber.
Meanwhile, the use of gamma radiation sterlisation from the onset of the glove making process, as a means of prevulcanisation, to the end of the production process, was discussed by both Dr Rosamma Alex of the Rubber Research Institute of India (RRII) and Eric Beers of Nordion, a Canadian company that provides sterilisation techniques.
The versatility of natural latex was demonstrated by Dr Azura A Rashid of Universiti Sains Malaysia who explained how natural latex can be used for cleaning compression moulds.
Innovative polymer synthesis in the manufacture of latex dispersions was covered by Dr Joachim Storsberg, Head of the Department Functional Medical Polymers of the German Fraunhofer Institute. In his presentation, he explained that dispersions can be used to facilitate modification of the surface properties of different materials. Furthermore, “synthesis and analysis are essential in respect to residues of reactive reagents,” he said.
Sören Butz of synthetic latex emulsion resins maker Synthomer spoke about how more “clever” chemistry could be used to tailor-make pressuresensitive adhesives.
Rounding up the presentations were David Hill of David Hill and Associates who focused on process validation of dipped condoms and gloves while Dr Bert Krutzer of Dutch polymers maker Kraton provided a comparison between the newest latex for dipping, polyisoprene latex, with natural rubber. The conference ended with RRII’s Dr Siby Varghese and Mahatma Gandhi University’s Professor Sabu Thomas describing the latest advances and applications in the field of nanotechnology.